SERVER-13961 Add OperationContext argument to Client::Context

Time tracking and database access in Client::Context require access to the
OperationContext. Adding it as argument.

This is in preparation for removing LockState from Client.

72 files changed, 1010 insertions, 898 deletions

diff --git a/src/mongo/db/catalog/collection_cursor_cache.cpp b/src/mongo/db/catalog/collection_cursor_cache.cpp
index 2e941dd1f40..c8e8feae704 100644
--- a/src/mongo/db/catalog/collection_cursor_cache.cpp
+++ b/src/mongo/db/catalog/collection_cursor_cache.cpp
@@ -191,7 +191,7 @@ namespace mongo {
         Database* db = dbHolder().get(txn, ns);
         if ( !db )
             return false;
-        Client::Context context( ns, db );
+        Client::Context context(txn, ns, db );
         Collection* collection = db->getCollection( txn, ns );
         if ( !collection ) {
             if ( checkAuth )
@@ -221,7 +221,7 @@ namespace mongo {
             Database* db = dbHolder().get(txn, ns);
             if ( !db )
                 continue;
-            Client::Context context( ns, db );
+            Client::Context context(txn,  ns, db );
             Collection* collection = db->getCollection( txn, ns );
             if ( collection == NULL ) {
                 continue;
diff --git a/src/mongo/db/catalog/database.cpp b/src/mongo/db/catalog/database.cpp
index affa5d64195..1238072ba59 100644
--- a/src/mongo/db/catalog/database.cpp
+++ b/src/mongo/db/catalog/database.cpp
@@ -513,7 +513,7 @@ namespace mongo {
         log() << "dropAllDatabasesExceptLocal " << n.size() << endl;
         for( vector<string>::iterator i = n.begin(); i != n.end(); i++ ) {
             if( *i != "local" ) {
-                Client::Context ctx(*i);
+                Client::Context ctx(txn, *i);
                 dropDatabase(txn, ctx.db());
             }
         }
diff --git a/src/mongo/db/catalog/database_holder.cpp b/src/mongo/db/catalog/database_holder.cpp
index e1f83b53e98..438be2fd6aa 100644
--- a/src/mongo/db/catalog/database_holder.cpp
+++ b/src/mongo/db/catalog/database_holder.cpp
@@ -141,8 +141,10 @@ namespace mongo {
         int nNotClosed = 0;
         for( set< string >::iterator i = dbs.begin(); i != dbs.end(); ++i ) {
             string name = *i;
+
             LOG(2) << "DatabaseHolder::closeAll name:" << name;
-            Client::Context ctx( name );
+            Client::Context ctx(txn, name);
+
             if( !force && BackgroundOperation::inProgForDb(name) ) {
                 log() << "WARNING: can't close database "
                       << name
diff --git a/src/mongo/db/catalog/index_catalog.cpp b/src/mongo/db/catalog/index_catalog.cpp
index 309775aed85..8d70c6b123c 100644
--- a/src/mongo/db/catalog/index_catalog.cpp
+++ b/src/mongo/db/catalog/index_catalog.cpp
@@ -420,7 +420,8 @@ namespace mongo {
             return;
         }
 
-        Client::Context context( _collection->ns().ns(),
+        Client::Context context( _txn,
+                                 _collection->ns().ns(),
                                  _collection->_database );
 
         // if we're here, the index build failed or was interrupted
diff --git a/src/mongo/db/client.cpp b/src/mongo/db/client.cpp
index fb87dc5b9a7..6cfefce96a6 100644
--- a/src/mongo/db/client.cpp
+++ b/src/mongo/db/client.cpp
@@ -54,7 +54,7 @@
 #include "mongo/db/instance.h"
 #include "mongo/db/json.h"
 #include "mongo/db/jsobj.h"
-#include "mongo/db/operation_context_impl.h"
+#include "mongo/db/operation_context.h"
 #include "mongo/db/repl/repl_coordinator_global.h"
 #include "mongo/db/repl/rs.h"
 #include "mongo/db/storage_options.h"
@@ -162,23 +162,27 @@ namespace mongo {
     }
 
     BSONObj CachedBSONObjBase::_tooBig = fromjson("{\"$msg\":\"query not recording (too large)\"}");
-    Client::Context::Context(const std::string& ns , Database * db) :
-        _client( currentClient.get() ), 
-        _justCreated(false),
-        _doVersion( true ),
-        _ns( ns ), 
-        _db(db)
-    {
+
+    Client::Context::Context(OperationContext* txn, const std::string& ns, Database * db)
+        : _client( currentClient.get() ), 
+          _justCreated(false),
+          _doVersion( true ),
+          _ns( ns ), 
+          _db(db),
+          _txn(txn) {
 
     }
 
-    Client::Context::Context(const string& ns, bool doVersion) :
-        _client( currentClient.get() ), 
-        _justCreated(false), // set for real in finishInit
-        _doVersion(doVersion),
-        _ns( ns ), 
-        _db(0) 
-    {
+    Client::Context::Context(OperationContext* txn,
+                             const string& ns,
+                             bool doVersion)
+        : _client( currentClient.get() ), 
+          _justCreated(false), // set for real in finishInit
+          _doVersion(doVersion),
+          _ns( ns ), 
+          _db(NULL),
+          _txn(txn) {
+
         _finishInit();
     }
        
@@ -191,7 +195,7 @@ namespace mongo {
             _lk.reset(new Lock::DBRead(txn->lockState(), ns));
             Database *db = dbHolder().get(txn, ns);
             if( db ) {
-                _c.reset(new Context(ns, db, doVersion));
+                _c.reset(new Context(txn, ns, db, doVersion));
                 return;
             }
         }
@@ -202,18 +206,18 @@ namespace mongo {
             if (txn->lockState()->isW()) {
                 // write locked already
                 DEV RARELY log() << "write locked on ReadContext construction " << ns << endl;
-                _c.reset(new Context(ns, doVersion));
+                _c.reset(new Context(txn, ns, doVersion));
             }
             else if (!txn->lockState()->isRecursive()) {
                 _lk.reset(0);
                 {
                     Lock::GlobalWrite w(txn->lockState());
-                    Context c(ns, doVersion);
+                    Context c(txn, ns, doVersion);
                 }
 
                 // db could be closed at this interim point -- that is ok, we will throw, and don't mind throwing.
                 _lk.reset(new Lock::DBRead(txn->lockState(), ns));
-                _c.reset(new Context(ns, doVersion));
+                _c.reset(new Context(txn, ns, doVersion));
             }
             else { 
                 uasserted(15928, str::stream() << "can't open a database from a nested read lock " << ns);
@@ -228,7 +232,8 @@ namespace mongo {
     Client::WriteContext::WriteContext(
                 OperationContext* opCtx, const std::string& ns, bool doVersion)
         : _lk(opCtx->lockState(), ns),
-          _c(ns, doVersion) {
+          _c(opCtx, ns, doVersion) {
+
     }
 
 
@@ -252,21 +257,24 @@ namespace mongo {
     }
 
     // invoked from ReadContext
-    Client::Context::Context(const string& ns, Database *db, bool doVersion) :
-        _client( currentClient.get() ), 
-        _justCreated(false),
-        _doVersion( doVersion ),
-        _ns( ns ), 
-        _db(db)
-    {
+    Client::Context::Context(OperationContext* txn,
+                             const string& ns,
+                             Database *db,
+                             bool doVersion)
+        : _client( currentClient.get() ), 
+          _justCreated(false),
+          _doVersion( doVersion ),
+          _ns( ns ), 
+          _db(db),
+          _txn(txn) {
+
         verify(_db);
         if (_doVersion) checkNotStale();
         _client->_curOp->enter( this );
     }
        
     void Client::Context::_finishInit() {
-        OperationContextImpl txn; // TODO get rid of this once reads require transactions
-        _db = dbHolder().getOrCreate(&txn, _ns, _justCreated);
+        _db = dbHolder().getOrCreate(_txn, _ns, _justCreated);
         invariant(_db);
 
         if( _doVersion ) checkNotStale();
@@ -276,7 +284,11 @@ namespace mongo {
     
     Client::Context::~Context() {
         DEV verify( _client == currentClient.get() );
-        _client->_curOp->recordGlobalTime( _timer.micros() );
+
+        // Lock must still be held
+        invariant(_txn->lockState()->isLocked());
+
+        _client->_curOp->recordGlobalTime(_txn->lockState()->isWriteLocked(), _timer.micros());
     }
 
     void Client::appendLastOp( BSONObjBuilder& b ) const {
diff --git a/src/mongo/db/client.h b/src/mongo/db/client.h
index 48a8d74dd18..cf5c9f38964 100644
--- a/src/mongo/db/client.h
+++ b/src/mongo/db/client.h
@@ -157,20 +157,20 @@ namespace mongo {
         /* Set database we want to use, then, restores when we finish (are out of scope)
            Note this is also helpful if an exception happens as the state if fixed up.
         */
-        class Context : boost::noncopyable {
+        class Context {
+            MONGO_DISALLOW_COPYING(Context);
         public:
             /** this is probably what you want */
-            Context(const std::string& ns,
-                    bool doVersion = true);
+            Context(OperationContext* txn, const std::string& ns, bool doVersion = true);
 
             /** note: this does not call finishInit -- i.e., does not call 
                       shardVersionOk() for example. 
                 see also: reset().
             */
-            Context(const std::string& ns , Database * db);
+            Context(OperationContext* txn, const std::string& ns, Database * db);
 
             // used by ReadContext
-            Context(const std::string& ns, Database *db, bool doVersion );
+            Context(OperationContext* txn, const std::string& ns, Database *db, bool doVersion);
 
             ~Context();
             Client* getClient() const { return _client; }
@@ -199,6 +199,7 @@ namespace mongo {
             bool _doVersion;
             const std::string _ns;
             Database * _db;
+            OperationContext* _txn;
             
             Timer _timer;
         }; // class Client::Context
diff --git a/src/mongo/db/commands/apply_ops.cpp b/src/mongo/db/commands/apply_ops.cpp
index 88c8c66f484..b3fa1b6ce2e 100644
--- a/src/mongo/db/commands/apply_ops.cpp
+++ b/src/mongo/db/commands/apply_ops.cpp
@@ -133,7 +133,7 @@ namespace mongo {
                 Lock::DBWrite lk(txn->lockState(), ns);
                 invariant(txn->lockState()->isRecursive());
 
-                Client::Context ctx(ns);
+                Client::Context ctx(txn, ns);
                 bool failed = repl::applyOperation_inlock(txn,
                                                              ctx.db(),
                                                              temp,
diff --git a/src/mongo/db/commands/collection_to_capped.cpp b/src/mongo/db/commands/collection_to_capped.cpp
index 7299f0abf29..476d80edf08 100644
--- a/src/mongo/db/commands/collection_to_capped.cpp
+++ b/src/mongo/db/commands/collection_to_capped.cpp
@@ -60,7 +60,7 @@ namespace mongo {
 
         // create new collection
         {
-            Client::Context ctx( toNs );
+            Client::Context ctx(txn,  toNs );
             BSONObjBuilder spec;
             spec.appendBool( "capped", true );
             spec.append( "size", size );
@@ -153,7 +153,7 @@ namespace mongo {
             }
 
             Lock::DBWrite dbXLock(txn->lockState(), dbname);
-            Client::Context ctx(dbname);
+            Client::Context ctx(txn, dbname);
 
             Status status = cloneCollectionAsCapped( txn, ctx.db(), from, to, size, temp, true );
             return appendCommandStatus( result, status );
@@ -200,7 +200,7 @@ namespace mongo {
             // calls renamecollection which does a global lock, so we must too:
             //
             Lock::GlobalWrite globalWriteLock(txn->lockState());
-            Client::Context ctx(dbname);
+            Client::Context ctx(txn, dbname);
 
             Database* db = ctx.db();
 
diff --git a/src/mongo/db/commands/compact.cpp b/src/mongo/db/commands/compact.cpp
index e9d4ca106d8..c0df090d29a 100644
--- a/src/mongo/db/commands/compact.cpp
+++ b/src/mongo/db/commands/compact.cpp
@@ -142,7 +142,7 @@ namespace mongo {
 
             Lock::DBWrite lk(txn->lockState(), ns.ns());
             BackgroundOperation::assertNoBgOpInProgForNs(ns.ns());
-            Client::Context ctx(ns);
+            Client::Context ctx(txn, ns);
 
             Collection* collection = ctx.db()->getCollection(txn, ns.ns());
             if( ! collection ) {
diff --git a/src/mongo/db/commands/count.cpp b/src/mongo/db/commands/count.cpp
index 48ebb4422e1..aa43882ea78 100644
--- a/src/mongo/db/commands/count.cpp
+++ b/src/mongo/db/commands/count.cpp
@@ -73,7 +73,7 @@ namespace mongo {
                        string &err,
                        int &errCode) {
         // Lock 'ns'.
-        Client::Context cx(ns);
+        Client::Context cx(txn, ns);
         Collection* collection = cx.db()->getCollection(txn, ns);
 
         if (NULL == collection) {
diff --git a/src/mongo/db/commands/cpuprofile.cpp b/src/mongo/db/commands/cpuprofile.cpp
index b6c6f923f83..de614b8a553 100644
--- a/src/mongo/db/commands/cpuprofile.cpp
+++ b/src/mongo/db/commands/cpuprofile.cpp
@@ -136,7 +136,7 @@ namespace mongo {
                                            BSONObjBuilder &result,
                                            bool fromRepl ) {
             Lock::DBWrite dbXLock(db);
-            Client::Context ctx(db);
+            Client::Context ctx(txn, db);
 
             std::string profileFilename = cmdObj[commandName]["profileFilename"].String();
             if ( ! ::ProfilerStart( profileFilename.c_str() ) ) {
@@ -154,7 +154,7 @@ namespace mongo {
                                           BSONObjBuilder &result,
                                           bool fromRepl ) {
             Lock::DBWrite dbXLock(db);
-            Client::Context ctx(db);
+            Client::Context ctx(txn, db);
 
             ::ProfilerStop();
             return true;
diff --git a/src/mongo/db/commands/drop_indexes.cpp b/src/mongo/db/commands/drop_indexes.cpp
index c659454d684..d5491d166e7 100644
--- a/src/mongo/db/commands/drop_indexes.cpp
+++ b/src/mongo/db/commands/drop_indexes.cpp
@@ -110,7 +110,7 @@ namespace mongo {
                 LOG(0) << "CMD: dropIndexes " << toDeleteNs << endl;
             }
 
-            Client::Context ctx(toDeleteNs);
+            Client::Context ctx(txn, toDeleteNs);
             Database* db = ctx.db();
 
             Collection* collection = db->getCollection( txn, toDeleteNs );
@@ -222,7 +222,7 @@ namespace mongo {
             LOG(0) << "CMD: reIndex " << toDeleteNs << endl;
 
             Lock::DBWrite dbXLock(txn->lockState(), dbname);
-            Client::Context ctx(toDeleteNs);
+            Client::Context ctx(txn, toDeleteNs);
 
             Collection* collection = ctx.db()->getCollection( txn, toDeleteNs );
 
diff --git a/src/mongo/db/commands/find_and_modify.cpp b/src/mongo/db/commands/find_and_modify.cpp
index 7c3221cbbb6..3981705ed00 100644
--- a/src/mongo/db/commands/find_and_modify.cpp
+++ b/src/mongo/db/commands/find_and_modify.cpp
@@ -94,7 +94,7 @@ namespace mongo {
             }
 
             Lock::DBWrite dbXLock(txn->lockState(), dbname);
-            Client::Context ctx(ns);
+            Client::Context ctx(txn, ns);
             
             return runNoDirectClient( txn, ns , 
                                       query , fields , update , 
@@ -134,7 +134,7 @@ namespace mongo {
                                       string& errmsg) {
 
             Lock::DBWrite lk(txn->lockState(), ns);
-            Client::Context cx( ns );
+            Client::Context cx(txn, ns);
             Collection* collection = cx.db()->getCollection( txn, ns );
 
             const WhereCallbackReal whereCallback = WhereCallbackReal(StringData(ns));
@@ -330,7 +330,7 @@ namespace mongo {
             }
 
             Lock::DBWrite dbXLock(txn->lockState(), dbname);
-            Client::Context ctx(ns);
+            Client::Context ctx(txn, ns);
 
             BSONObj out = db.findOne(ns, q, fields);
             if (out.isEmpty()) {
diff --git a/src/mongo/db/commands/mr.cpp b/src/mongo/db/commands/mr.cpp
index 38dbceefe4d..b359a6fa3e4 100644
--- a/src/mongo/db/commands/mr.cpp
+++ b/src/mongo/db/commands/mr.cpp
@@ -588,7 +588,7 @@ namespace mongo {
 
                     bool found;
                     {
-                        Client::Context tx( _config.outputOptions.finalNamespace );
+                        Client::Context tx(txn, _config.outputOptions.finalNamespace);
                         Collection* coll =
                             tx.db()->getCollection(_txn, _config.outputOptions.finalNamespace);
                         found = Helpers::findOne(_txn,
@@ -1290,7 +1290,7 @@ namespace mongo {
 
                         // This context does no version check, safe b/c we checked earlier and have an
                         // open cursor
-                        scoped_ptr<Client::Context> ctx(new Client::Context(config.ns, false));
+                        scoped_ptr<Client::Context> ctx(new Client::Context(txn, config.ns, false));
 
                         const NamespaceString nss(config.ns);
                         const WhereCallbackReal whereCallback(nss.db());
@@ -1349,7 +1349,8 @@ namespace mongo {
                                 lock.reset();
                                 state.reduceAndSpillInMemoryStateIfNeeded();
                                 lock.reset(new Lock::DBRead(txn->lockState(), config.ns));
-                                ctx.reset(new Client::Context(config.ns, false));
+
+                                ctx.reset(new Client::Context(txn, config.ns, false));
 
                                 reduceTime += t.micros();
 
diff --git a/src/mongo/db/commands/rename_collection.cpp b/src/mongo/db/commands/rename_collection.cpp
index bae48fcc17f..a25b2e19a09 100644
--- a/src/mongo/db/commands/rename_collection.cpp
+++ b/src/mongo/db/commands/rename_collection.cpp
@@ -139,7 +139,7 @@ namespace mongo {
             std::vector<BSONObj> indexesInProg;
 
             {
-                Client::Context srcCtx( source );
+                Client::Context srcCtx(txn, source);
                 Collection* sourceColl = srcCtx.db()->getCollection( txn, source );
 
                 if ( !sourceColl ) {
@@ -182,7 +182,7 @@ namespace mongo {
             }
 
             {
-                Client::Context ctx( target );
+                Client::Context ctx(txn,  target );
 
                 // Check if the target namespace exists and if dropTarget is true.
                 // If target exists and dropTarget is not true, return false.
@@ -245,7 +245,7 @@ namespace mongo {
             Collection* sourceColl = NULL;
 
             {
-                Client::Context srcCtx( source );
+                Client::Context srcCtx(txn, source);
                 sourceColl = srcCtx.db()->getCollection( txn, source );
                 sourceIt.reset( sourceColl->getIterator( DiskLoc(), false, CollectionScanParams::FORWARD ) );
             }
@@ -254,12 +254,12 @@ namespace mongo {
             while ( !sourceIt->isEOF() ) {
                 BSONObj o;
                 {
-                    Client::Context srcCtx( source );
+                    Client::Context srcCtx(txn, source);
                     o = sourceColl->docFor(sourceIt->getNext());
                 }
                 // Insert and check return status of insert.
                 {
-                    Client::Context ctx( target );
+                    Client::Context ctx(txn,  target );
                     if ( !targetColl )
                         targetColl = ctx.db()->getCollection( txn, target );
                     // No logOp necessary because the entire renameCollection command is one logOp.
@@ -275,7 +275,7 @@ namespace mongo {
 
             // If inserts were unsuccessful, drop the target collection and return false.
             if ( !insertSuccessful ) {
-                Client::Context ctx( target );
+                Client::Context ctx(txn,  target );
                 Status s = ctx.db()->dropCollection( txn, target );
                 if ( !s.isOK() )
                     errmsg = s.toString();
@@ -287,7 +287,7 @@ namespace mongo {
             vector<BSONObj> copiedIndexes;
             bool indexSuccessful = true;
             {
-                Client::Context srcCtx( source );
+                Client::Context srcCtx(txn, source);
                 IndexCatalog::IndexIterator sourceIndIt =
                     sourceColl->getIndexCatalog()->getIndexIterator( true );
 
@@ -313,7 +313,7 @@ namespace mongo {
             }
 
             {
-                Client::Context ctx( target );
+                Client::Context ctx(txn,  target );
                 if ( !targetColl )
                     targetColl = ctx.db()->getCollection( txn, target );
 
@@ -339,7 +339,7 @@ namespace mongo {
 
             // Drop the source collection.
             {
-                Client::Context srcCtx( source );
+                Client::Context srcCtx(txn, source);
                 Status s = srcCtx.db()->dropCollection( txn, source );
                 if ( !s.isOK() ) {
                     errmsg = s.toString();
diff --git a/src/mongo/db/commands/test_commands.cpp b/src/mongo/db/commands/test_commands.cpp
index 58d5e143a11..20175588afc 100644
--- a/src/mongo/db/commands/test_commands.cpp
+++ b/src/mongo/db/commands/test_commands.cpp
@@ -62,7 +62,7 @@ namespace mongo {
             BSONObj obj = cmdObj[ "obj" ].embeddedObjectUserCheck();
 
             Lock::DBWrite lk(txn->lockState(), ns);
-            Client::Context ctx( ns );
+            Client::Context ctx(txn,  ns );
             Database* db = ctx.db();
             Collection* collection = db->getCollection( txn, ns );
             if ( !collection ) {
diff --git a/src/mongo/db/commands/write_commands/batch_executor.cpp b/src/mongo/db/commands/write_commands/batch_executor.cpp
index 52acb7aae6f..39b5e7c0014 100644
--- a/src/mongo/db/commands/write_commands/batch_executor.cpp
+++ b/src/mongo/db/commands/write_commands/batch_executor.cpp
@@ -918,8 +918,9 @@ namespace mongo {
         if (!checkIndexConstraints(txn, &shardingState, *request, result)) {
             return false;
         }
-        _context.reset(new Client::Context(request->getNS(),
-                                           false /* don't check version */));
+
+        _context.reset(new Client::Context(txn, request->getNS(), false));
+
         Database* database = _context->db();
         dassert(database);
         _collection = database->getCollection(txn, request->getTargetingNS());
@@ -1098,7 +1099,7 @@ namespace mongo {
         if (!checkShardVersion(txn, &shardingState, *updateItem.getRequest(), result))
             return;
 
-        Client::Context ctx(nsString.ns(), false /* don't check version */);
+        Client::Context ctx(txn, nsString.ns(), false /* don't check version */);
 
         try {
             UpdateResult res = executor.execute(txn, ctx.db());
@@ -1159,8 +1160,7 @@ namespace mongo {
 
         // Context once we're locked, to set more details in currentOp()
         // TODO: better constructor?
-        Client::Context writeContext( nss.ns(),
-                                      false /* don't check version */);
+        Client::Context writeContext(txn, nss.ns(), false /* don't check version */);
 
         try {
             result->getStats().n = executor.execute(txn, writeContext.db());
diff --git a/src/mongo/db/curop.cpp b/src/mongo/db/curop.cpp
index 178166402d3..2f968ca4979 100644
--- a/src/mongo/db/curop.cpp
+++ b/src/mongo/db/curop.cpp
@@ -158,12 +158,8 @@ namespace mongo {
         _dbprofile = std::max( context->_db ? context->_db->getProfilingLevel() : 0 , _dbprofile );
     }
 
-    void CurOp::recordGlobalTime( long long micros ) const {
-        if ( _client ) {
-            const LockState& ls = _client->lockState();
-            verify( ls.threadState() );
-            Top::global.record( _ns , _op , ls.isWriteLocked() ? 1 : -1 , micros , _isCommand );
-        }
+    void CurOp::recordGlobalTime(bool isWriteLocked, long long micros) const {
+        Top::global.record(_ns, _op, isWriteLocked ? 1 : -1, micros, _isCommand);
     }
 
     void CurOp::reportState(BSONObjBuilder* builder) {
diff --git a/src/mongo/db/curop.h b/src/mongo/db/curop.h
index f24da292c98..ee52d2682a9 100644
--- a/src/mongo/db/curop.h
+++ b/src/mongo/db/curop.h
@@ -305,7 +305,7 @@ namespace mongo {
         long long getExpectedLatencyMs() const { return _expectedLatencyMs; }
         void setExpectedLatencyMs( long long latency ) { _expectedLatencyMs = latency; }
 
-        void recordGlobalTime( long long micros ) const;
+        void recordGlobalTime(bool isWriteLocked, long long micros) const;
         
         const LockStat& lockStat() const { return _lockStat; }
         LockStat& lockStat() { return _lockStat; }
diff --git a/src/mongo/db/db.cpp b/src/mongo/db/db.cpp
index 913419ef4f0..75242557c32 100644
--- a/src/mongo/db/db.cpp
+++ b/src/mongo/db/db.cpp
@@ -335,7 +335,7 @@ namespace mongo {
             string dbName = *i;
             LOG(1) << "\t" << dbName << endl;
 
-            Client::Context ctx( dbName );
+            Client::Context ctx(&txn,  dbName );
 
             if (repl::replSettings.usingReplSets()) {
                 // we only care about the _id index if we are in a replset
diff --git a/src/mongo/db/dbcommands.cpp b/src/mongo/db/dbcommands.cpp
index 4d7f8000f15..8dfc574c064 100644
--- a/src/mongo/db/dbcommands.cpp
+++ b/src/mongo/db/dbcommands.cpp
@@ -181,7 +181,7 @@ namespace mongo {
                 // this is suboptimal but syncDataAndTruncateJournal is called from dropDatabase,
                 // and that may need a global lock.
                 Lock::GlobalWrite lk(txn->lockState());
-                Client::Context context(dbname);
+                Client::Context context(txn, dbname);
 
                 log() << "dropDatabase " << dbname << " starting" << endl;
 
@@ -258,7 +258,7 @@ namespace mongo {
             // SERVER-4328 todo don't lock globally. currently syncDataAndTruncateJournal is being
             // called within, and that requires a global lock i believe.
             Lock::GlobalWrite lk(txn->lockState());
-            Client::Context context( dbname );
+            Client::Context context(txn,  dbname );
 
             log() << "repairDatabase " << dbname;
             std::vector<BSONObj> indexesInProg = stopIndexBuilds(txn, context.db(), cmdObj);
@@ -331,7 +331,7 @@ namespace mongo {
             // in the local database.
             //
             Lock::DBWrite dbXLock(txn->lockState(), dbname);
-            Client::Context ctx(dbname);
+            Client::Context ctx(txn, dbname);
 
             BSONElement e = cmdObj.firstElement();
             result.append("was", ctx.db()->getProfilingLevel());
@@ -381,7 +381,7 @@ namespace mongo {
             // locking, but originally the lock was set to be WRITE, so preserving the behaviour.
             //
             Lock::DBWrite dbXLock(txn->lockState(), dbname);
-            Client::Context ctx(dbname);
+            Client::Context ctx(txn, dbname);
 
             int was = _diaglog.setLevel( cmdObj.firstElement().numberInt() );
             _diaglog.flush();
@@ -436,7 +436,7 @@ namespace mongo {
             }
 
             Lock::DBWrite dbXLock(txn->lockState(), dbname);
-            Client::Context ctx(nsToDrop);
+            Client::Context ctx(txn, nsToDrop);
             Database* db = ctx.db();
 
             Collection* coll = db->getCollection( txn, nsToDrop );
@@ -534,7 +534,7 @@ namespace mongo {
                         options.hasField("$nExtents"));
 
             Lock::DBWrite dbXLock(txn->lockState(), dbname);
-            Client::Context ctx(ns);
+            Client::Context ctx(txn, ns);
 
             // Create collection.
             return appendCommandStatus( result,
@@ -648,7 +648,7 @@ namespace mongo {
 
         bool run(OperationContext* txn, const string& dbname , BSONObj& jsobj, int, string& errmsg, BSONObjBuilder& result, bool /*fromRepl*/) {
             Lock::GlobalWrite globalWriteLock(txn->lockState());
-            Client::Context ctx(dbname);
+            Client::Context ctx(txn, dbname);
 
             try {
                 return dbHolder().closeAll(txn, result, false);
@@ -1032,7 +1032,7 @@ namespace mongo {
             const string ns = dbname + "." + jsobj.firstElement().valuestr();
 
             Lock::DBWrite dbXLock(txn->lockState(), dbname);
-            Client::Context ctx( ns );
+            Client::Context ctx(txn,  ns );
 
             Collection* coll = ctx.db()->getCollection( txn, ns );
             if ( !coll ) {
diff --git a/src/mongo/db/dbeval.cpp b/src/mongo/db/dbeval.cpp
index f2076e97178..e5bd01890e7 100644
--- a/src/mongo/db/dbeval.cpp
+++ b/src/mongo/db/dbeval.cpp
@@ -143,7 +143,7 @@ namespace mongo {
             }
 
             Lock::GlobalWrite lk(txn->lockState());
-            Client::Context ctx( dbname );
+            Client::Context ctx(txn,  dbname );
 
             return dbEval(dbname, cmdObj, result, errmsg);
         }
diff --git a/src/mongo/db/dbhelpers.cpp b/src/mongo/db/dbhelpers.cpp
index abbeea15a86..0de77233f93 100644
--- a/src/mongo/db/dbhelpers.cpp
+++ b/src/mongo/db/dbhelpers.cpp
@@ -181,7 +181,7 @@ namespace mongo {
        Returns: true if object exists.
     */
     bool Helpers::getSingleton(OperationContext* txn, const char *ns, BSONObj& result) {
-        Client::Context context(ns);
+        Client::Context context(txn, ns);
         auto_ptr<Runner> runner(InternalPlanner::collectionScan(ns,
                                                                 context.db()->getCollection(txn,
                                                                                             ns)));
@@ -191,7 +191,7 @@ namespace mongo {
     }
 
     bool Helpers::getLast(OperationContext* txn, const char *ns, BSONObj& result) {
-        Client::Context ctx(ns);
+        Client::Context ctx(txn, ns);
         Collection* coll = ctx.db()->getCollection( txn, ns );
         auto_ptr<Runner> runner(InternalPlanner::collectionScan(ns,
                                                                 coll,
@@ -209,7 +209,7 @@ namespace mongo {
         BSONObj id = e.wrap();
 
         OpDebug debug;
-        Client::Context context(ns);
+        Client::Context context(txn, ns);
 
         const NamespaceString requestNs(ns);
         UpdateRequest request(requestNs);
@@ -227,7 +227,7 @@ namespace mongo {
 
     void Helpers::putSingleton(OperationContext* txn, const char *ns, BSONObj obj) {
         OpDebug debug;
-        Client::Context context(ns);
+        Client::Context context(txn, ns);
 
         const NamespaceString requestNs(ns);
         UpdateRequest request(requestNs);
@@ -245,7 +245,7 @@ namespace mongo {
 
     void Helpers::putSingletonGod(OperationContext* txn, const char *ns, BSONObj obj, bool logTheOp) {
         OpDebug debug;
-        Client::Context context(ns);
+        Client::Context context(txn, ns);
 
         const NamespaceString requestNs(ns);
         UpdateRequest request(requestNs);
@@ -546,7 +546,7 @@ namespace mongo {
 
 
     void Helpers::emptyCollection(OperationContext* txn, const char *ns) {
-        Client::Context context(ns);
+        Client::Context context(txn, ns);
         deleteObjects(txn, context.db(), ns, BSONObj(), false);
     }
 
diff --git a/src/mongo/db/instance.cpp b/src/mongo/db/instance.cpp
index 745ab93bd52..3edb27e5e65 100644
--- a/src/mongo/db/instance.cpp
+++ b/src/mongo/db/instance.cpp
@@ -615,7 +615,7 @@ namespace mongo {
         if ( ! broadcast && handlePossibleShardedMessage( m , 0 ) )
             return;
 
-        Client::Context ctx( ns );
+        Client::Context ctx(txn,  ns );
 
         UpdateResult res = executor.execute(txn, ctx.db());
 
@@ -654,7 +654,7 @@ namespace mongo {
         if ( ! broadcast && handlePossibleShardedMessage( m , 0 ) )
             return;
 
-        Client::Context ctx(ns);
+        Client::Context ctx(txn, ns);
 
         long long n = executor.execute(txn, ctx.db());
         lastError.getSafe()->recordDelete( n );
@@ -895,7 +895,7 @@ namespace mongo {
         if ( handlePossibleShardedMessage( m , 0 ) )
             return;
 
-        Client::Context ctx(ns);
+        Client::Context ctx(txn, ns);
 
         if (multi.size() > 1) {
             const bool keepGoing = d.reservedField() & InsertOption_ContinueOnError;
diff --git a/src/mongo/db/introspect.cpp b/src/mongo/db/introspect.cpp
index 667964aee1a..87b74e6201a 100644
--- a/src/mongo/db/introspect.cpp
+++ b/src/mongo/db/introspect.cpp
@@ -138,8 +138,7 @@ namespace {
             // we're sometimes inside the lock already
             Lock::DBWrite lk(txn->lockState(), currentOp.getNS() );
             if (dbHolder().get(txn, nsToDatabase(currentOp.getNS())) != NULL) {
-
-                Client::Context cx(currentOp.getNS(), false);
+                Client::Context cx(txn, currentOp.getNS(), false);
                 _profile(txn, c, cx.db(), currentOp, profileBufBuilder);
             }
             else {
diff --git a/src/mongo/db/operation_context_impl.h b/src/mongo/db/operation_context_impl.h
index 3acadbca4a5..ed681f1940a 100644
--- a/src/mongo/db/operation_context_impl.h
+++ b/src/mongo/db/operation_context_impl.h
@@ -25,13 +25,13 @@
  *    exception statement from all source files in the program, then also delete
  *    it in the license file.
  */
+#pragma once
 
 #include <boost/scoped_ptr.hpp>
 #include <string>
 
 #include "mongo/db/operation_context.h"
 
-#pragma once
 
 namespace mongo {
 
diff --git a/src/mongo/db/operation_context_noop.h b/src/mongo/db/operation_context_noop.h
index 527348b1537..f3964494936 100644
--- a/src/mongo/db/operation_context_noop.h
+++ b/src/mongo/db/operation_context_noop.h
@@ -25,13 +25,13 @@
  *    exception statement from all source files in the program, then also delete
  *    it in the license file.
  */
+#pragma once
 
 #include "mongo/db/operation_context.h"
 #include "mongo/db/client.h"
 #include "mongo/db/curop.h"
-
 #include "mongo/db/storage/recovery_unit_noop.h"
-#pragma once
+
 
 namespace mongo {
 
diff --git a/src/mongo/db/pipeline/document_source_cursor.cpp b/src/mongo/db/pipeline/document_source_cursor.cpp
index 62b8b52645a..6c4d8c5d6c0 100644
--- a/src/mongo/db/pipeline/document_source_cursor.cpp
+++ b/src/mongo/db/pipeline/document_source_cursor.cpp
@@ -80,7 +80,7 @@ namespace mongo {
         // We have already validated the sharding version when we constructed the Runner
         // so we shouldn't check it again.
         Lock::DBRead lk(pExpCtx->opCtx->lockState(), _ns);
-        Client::Context ctx(_ns, /*doVersion=*/false);
+        Client::Context ctx(pExpCtx->opCtx, _ns, /*doVersion=*/false);
 
         _runner->restoreState(pExpCtx->opCtx);
 
@@ -200,7 +200,8 @@ namespace {
         scoped_ptr<TypeExplain> plan;
         {
             Lock::DBRead lk(pExpCtx->opCtx->lockState(), _ns);
-            Client::Context ctx(_ns, /*doVersion=*/false);
+            Client::Context ctx(pExpCtx->opCtx, _ns, /*doVersion=*/ false);
+
             massert(17392, "No _runner. Were we disposed before explained?",
                     _runner);
 
diff --git a/src/mongo/db/repl/master_slave.cpp b/src/mongo/db/repl/master_slave.cpp
index 2b3eca3de42..bdbbc14cc41 100644
--- a/src/mongo/db/repl/master_slave.cpp
+++ b/src/mongo/db/repl/master_slave.cpp
@@ -196,9 +196,10 @@ namespace repl {
         LOG( 1 ) << "Saving repl source: " << o << endl;
 
         {
-            OpDebug debug;
-            Client::Context ctx("local.sources");
             OperationContextImpl txn;
+            OpDebug debug;
+
+            Client::Context ctx(&txn, "local.sources");
 
             const NamespaceString requestNs("local.sources");
             UpdateRequest request(requestNs);
@@ -234,7 +235,7 @@ namespace repl {
     */
     void ReplSource::loadAll(OperationContext* txn, SourceVector &v) {
         const char* localSources = "local.sources";
-        Client::Context ctx(localSources);
+        Client::Context ctx(txn, localSources);
         SourceVector old = v;
         v.clear();
 
@@ -364,7 +365,7 @@ namespace repl {
 
     void ReplSource::resyncDrop( OperationContext* txn, const string& db ) {
         log() << "resync: dropping database " << db;
-        Client::Context ctx(db);
+        Client::Context ctx(txn, db);
         dropDatabase(txn, ctx.db());
     }
 
@@ -513,8 +514,9 @@ namespace repl {
             ___databaseIgnorer.doIgnoreUntilAfter( *i, lastTime );
             incompleteCloneDbs.erase(*i);
             addDbNextPass.erase(*i);
-            Client::Context ctx(*i);
-            dropDatabase(txn, ctx.db() );
+
+            Client::Context ctx(txn, *i);
+            dropDatabase(txn, ctx.db());
         }
         
         massert(14034, "Duplicate database names present after attempting to delete duplicates",
@@ -626,11 +628,11 @@ namespace repl {
         if (!handleDuplicateDbName(txn, op, ns, clientName)) {
             return;   
         }
-                
+
         // This code executes on the slaves only, so it doesn't need to be sharding-aware since
         // mongos will not send requests there. That's why the last argument is false (do not do
         // version checking).
-        Client::Context ctx(ns, false);
+        Client::Context ctx(txn, ns, false);
         ctx.getClient()->curop()->reset();
 
         bool empty = ctx.db()->getDatabaseCatalogEntry()->isEmpty();
@@ -661,7 +663,7 @@ namespace repl {
                     log() << "An earlier initial clone of '" << clientName << "' did not complete, now resyncing." << endl;
                 }
                 save();
-                Client::Context ctx(ns);
+                Client::Context ctx(txn, ns);
                 nClonedThisPass++;
                 resync(txn, ctx.db()->name());
                 addDbNextPass.erase(clientName);
@@ -1285,7 +1287,7 @@ namespace repl {
                     BSONObjBuilder b;
                     b.append(_id);
                     BSONObj result;
-                    Client::Context ctx( ns );
+                    Client::Context ctx(&txn, ns);
                     if( Helpers::findById(&txn, ctx.db(), ns, b.done(), result) )
                         _dummy_z += result.objsize(); // touch
                 }
diff --git a/src/mongo/db/repl/oplog.cpp b/src/mongo/db/repl/oplog.cpp
index 632986c9426..18754046e2f 100644
--- a/src/mongo/db/repl/oplog.cpp
+++ b/src/mongo/db/repl/oplog.cpp
@@ -123,7 +123,8 @@ namespace repl {
 
         {
             if ( localOplogRSCollection == 0 ) {
-                Client::Context ctx(rsoplog);
+                Client::Context ctx(&txn, rsoplog);
+
                 localDB = ctx.db();
                 verify( localDB );
                 localOplogRSCollection = localDB->getCollection( &txn, rsoplog );
@@ -131,7 +132,7 @@ namespace repl {
                         "local.oplog.rs missing. did you drop it? if so restart server",
                         localOplogRSCollection);
             }
-            Client::Context ctx(rsoplog, localDB);
+            Client::Context ctx(&txn, rsoplog, localDB);
             checkOplogInsert( localOplogRSCollection->insertDocument( &txn, op, false ) );
 
             /* todo: now() has code to handle clock skew.  but if the skew server to server is large it will get unhappy.
@@ -283,14 +284,14 @@ namespace repl {
         DEV verify( logNS == 0 ); // check this was never a master/slave master
 
         if ( localOplogRSCollection == 0 ) {
-            Client::Context ctx(rsoplog);
+            Client::Context ctx(txn, rsoplog);
             localDB = ctx.db();
             verify( localDB );
             localOplogRSCollection = localDB->getCollection( txn, rsoplog );
             massert(13347, "local.oplog.rs missing. did you drop it? if so restart server", localOplogRSCollection);
         }
 
-        Client::Context ctx(rsoplog, localDB);
+        Client::Context ctx(txn, rsoplog, localDB);
         OplogDocWriter writer( partial, obj );
         checkOplogInsert( localOplogRSCollection->insertDocument( txn, &writer, false ) );
 
@@ -361,14 +362,14 @@ namespace repl {
         }
 
         if ( localOplogMainCollection == 0 ) {
-            Client::Context ctx(logNS);
+            Client::Context ctx(txn, logNS);
             localDB = ctx.db();
             verify( localDB );
             localOplogMainCollection = localDB->getCollection(txn, logNS);
             verify( localOplogMainCollection );
         }
 
-        Client::Context ctx(logNS , localDB);
+        Client::Context ctx(txn, logNS , localDB);
         OplogDocWriter writer( partial, obj );
         checkOplogInsert( localOplogMainCollection->insertDocument( txn, &writer, false ) );
 
@@ -454,7 +455,7 @@ namespace repl {
         if( rs )
             ns = rsoplog;
 
-        Client::Context ctx(ns);
+        Client::Context ctx(&txn, ns);
         Collection* collection = ctx.db()->getCollection( &txn, ns );
 
         if ( collection ) {
diff --git a/src/mongo/db/repl/repl_set_impl.cpp b/src/mongo/db/repl/repl_set_impl.cpp
index 5a9d393ae4e..030da5fc532 100644
--- a/src/mongo/db/repl/repl_set_impl.cpp
+++ b/src/mongo/db/repl/repl_set_impl.cpp
@@ -105,7 +105,7 @@ namespace {
             if (*it == "local")
                 continue;
 
-            Client::Context ctx(*it);
+            Client::Context ctx(&txn, *it);
             ctx.db()->clearTmpCollections(&txn);
         }
     }
diff --git a/src/mongo/db/repl/resync.cpp b/src/mongo/db/repl/resync.cpp
index d1c693d4b92..ca16a00139a 100644
--- a/src/mongo/db/repl/resync.cpp
+++ b/src/mongo/db/repl/resync.cpp
@@ -68,7 +68,7 @@ namespace repl {
 
             const std::string ns = parseNs(dbname, cmdObj);
             Lock::GlobalWrite globalWriteLock(txn->lockState());
-            Client::Context ctx(ns);
+            Client::Context ctx(txn, ns);
             if (replSettings.usingReplSets()) {
                 if (!theReplSet) {
                     errmsg = "no replication yet active";
diff --git a/src/mongo/db/repl/rs_rollback.cpp b/src/mongo/db/repl/rs_rollback.cpp
index 985d751aa8e..19a2b70fbf7 100644
--- a/src/mongo/db/repl/rs_rollback.cpp
+++ b/src/mongo/db/repl/rs_rollback.cpp
@@ -230,7 +230,7 @@ namespace repl {
     int getRBID(DBClientConnection*);
 
     static void syncRollbackFindCommonPoint(OperationContext* txn, DBClientConnection* them, FixUpInfo& fixUpInfo) {
-        Client::Context ctx(rsoplog);
+        Client::Context ctx(txn, rsoplog);
 
         boost::scoped_ptr<Runner> runner(
                 InternalPlanner::collectionScan(rsoplog,
@@ -499,13 +499,13 @@ namespace repl {
         for (set<string>::iterator it = fixUpInfo.toDrop.begin();
                 it != fixUpInfo.toDrop.end();
                 it++) {
-            Client::Context ctx(*it);
+            Client::Context ctx(txn, *it);
             log() << "replSet rollback drop: " << *it << rsLog;
             ctx.db()->dropCollection(txn, *it);
         }
 
         sethbmsg("rollback 4.7");
-        Client::Context ctx(rsoplog);
+        Client::Context ctx(txn, rsoplog);
         Collection* oplogCollection = ctx.db()->getCollection(txn, rsoplog);
         uassert(13423,
                 str::stream() << "replSet error in rollback can't find " << rsoplog,
@@ -543,7 +543,7 @@ namespace repl {
                     removeSaver.reset(new Helpers::RemoveSaver("rollback", "", doc.ns));
 
                 // todo: lots of overhead in context, this can be faster
-                Client::Context ctx(doc.ns);
+                Client::Context ctx(txn, doc.ns);
 
                 // Add the doc to our rollback file
                 BSONObj obj;
diff --git a/src/mongo/db/repl/rs_sync.cpp b/src/mongo/db/repl/rs_sync.cpp
index 41b7247bd52..b0a16002336 100644
--- a/src/mongo/db/repl/rs_sync.cpp
+++ b/src/mongo/db/repl/rs_sync.cpp
@@ -228,8 +228,9 @@ namespace repl {
     bool ReplSetImpl::resync(string& errmsg) {
         changeState(MemberState::RS_RECOVERING);
 
-        Client::Context ctx("local");
         OperationContextImpl txn;
+        Client::Context ctx(&txn, "local");
+
         ctx.db()->dropCollection(&txn, "local.oplog.rs");
         {
             boost::unique_lock<boost::mutex> lock(theReplSet->initialSyncMutex);
diff --git a/src/mongo/db/repl/sync.cpp b/src/mongo/db/repl/sync.cpp
index 153e7e048e2..c9f43ebf894 100644
--- a/src/mongo/db/repl/sync.cpp
+++ b/src/mongo/db/repl/sync.cpp
@@ -109,7 +109,7 @@ namespace repl {
 
         // should already have write lock
         const char *ns = o.getStringField("ns");
-        Client::Context ctx(ns);
+        Client::Context ctx(txn, ns);
 
         // we don't have the object yet, which is possible on initial sync.  get it.
         log() << "replication info adding missing object" << endl; // rare enough we can log
diff --git a/src/mongo/db/repl/sync_tail.cpp b/src/mongo/db/repl/sync_tail.cpp
index 9719dceeeee..ce4e3902a59 100644
--- a/src/mongo/db/repl/sync_tail.cpp
+++ b/src/mongo/db/repl/sync_tail.cpp
@@ -106,7 +106,7 @@ namespace repl {
             lk.reset(new Lock::DBWrite(txn->lockState(), ns)); 
         }
 
-        Client::Context ctx(ns);
+        Client::Context ctx(txn, ns);
         ctx.getClient()->curop()->reset();
         // For non-initial-sync, we convert updates to upserts
         // to suppress errors when replaying oplog entries.
diff --git a/src/mongo/db/storage/mmap_v1/repair_database.cpp b/src/mongo/db/storage/mmap_v1/repair_database.cpp
index f1061147a70..dc9e50f1f6c 100644
--- a/src/mongo/db/storage/mmap_v1/repair_database.cpp
+++ b/src/mongo/db/storage/mmap_v1/repair_database.cpp
@@ -247,7 +247,9 @@ namespace mongo {
 
             try {
                 _txn->recoveryUnit()->syncDataAndTruncateJournal();
+
                 globalStorageEngine->flushAllFiles(true); // need both in case journaling is disabled
+
                 MONGO_ASSERT_ON_EXCEPTION( boost::filesystem::remove_all( _path ) );
             }
             catch ( DBException& e ) {
@@ -335,7 +337,7 @@ namespace mongo {
             map<string,CollectionOptions> namespacesToCopy;
             {
                 string ns = dbName + ".system.namespaces";
-                Client::Context ctx( ns );
+                Client::Context ctx(txn,  ns );
                 Collection* coll = originalDatabase->getCollection( txn, ns );
                 if ( coll ) {
                     scoped_ptr<RecordIterator> it( coll->getIterator( DiskLoc(),
@@ -377,11 +379,11 @@ namespace mongo {
 
                 Collection* tempCollection = NULL;
                 {
-                    Client::Context tempContext( ns, tempDatabase );
+                    Client::Context tempContext(txn, ns, tempDatabase );
                     tempCollection = tempDatabase->createCollection( txn, ns, options, true, false );
                 }
 
-                Client::Context readContext( ns, originalDatabase );
+                Client::Context readContext(txn, ns, originalDatabase);
                 Collection* originalCollection = originalDatabase->getCollection( txn, ns );
                 invariant( originalCollection );
 
@@ -397,7 +399,7 @@ namespace mongo {
                         indexes.push_back( desc->infoObj() );
                     }
 
-                    Client::Context tempContext( ns, tempDatabase );
+                    Client::Context tempContext(txn, ns, tempDatabase);
                     Status status = indexBlock.init( indexes );
                     if ( !status.isOK() )
                         return status;
@@ -413,7 +415,7 @@ namespace mongo {
 
                     BSONObj doc = originalCollection->docFor( loc );
 
-                    Client::Context tempContext( ns, tempDatabase );
+                    Client::Context tempContext(txn, ns, tempDatabase);
                     StatusWith<DiskLoc> result = tempCollection->insertDocument( txn, doc, indexBlock );
                     if ( !result.isOK() )
                         return result.getStatus();
@@ -423,7 +425,7 @@ namespace mongo {
                 }
 
                 {
-                    Client::Context tempContext( ns, tempDatabase );
+                    Client::Context tempContext(txn, ns, tempDatabase);
                     Status status = indexBlock.commit();
                     if ( !status.isOK() )
                         return status;
@@ -435,7 +437,6 @@ namespace mongo {
             globalStorageEngine->flushAllFiles(true); // need both in case journaling is disabled
 
             txn->checkForInterrupt(false);
-
         }
 
         // at this point if we abort, we don't want to delete new files
@@ -444,7 +445,7 @@ namespace mongo {
         if ( repairFileDeleter.get() )
             repairFileDeleter->success();
 
-        Client::Context ctx( dbName );
+        Client::Context ctx(txn, dbName);
         Database::closeDatabase(txn, dbName);
 
         if ( backupOriginalFiles ) {
diff --git a/src/mongo/dbtests/clienttests.cpp b/src/mongo/dbtests/clienttests.cpp
index 527f52f2554..1ba539f0266 100644
--- a/src/mongo/dbtests/clienttests.cpp
+++ b/src/mongo/dbtests/clienttests.cpp
@@ -40,19 +40,23 @@ namespace ClientTests {
     class Base {
     public:
 
-        Base( string coll ) {
+        Base( string coll ) : _ns("test." + coll) {
+            OperationContextImpl txn;
+            DBDirectClient db(&txn);
+
             db.dropDatabase("test");
-            _ns = (string)"test." + coll;
         }
 
         virtual ~Base() {
+            OperationContextImpl txn;
+            DBDirectClient db(&txn);
+
             db.dropCollection( _ns );
         }
 
         const char * ns() { return _ns.c_str(); }
 
-        string _ns;
-        DBDirectClient db;
+        const string _ns;
     };
 
 
@@ -60,6 +64,9 @@ namespace ClientTests {
     public:
         DropIndex() : Base( "dropindex" ) {}
         void run() {
+            OperationContextImpl txn;
+            DBDirectClient db(&txn);
+
             db.insert( ns() , BSON( "x" << 2 ) );
             ASSERT_EQUALS( 1 , db.getIndexes( ns() )->itcount() );
 
@@ -81,6 +88,8 @@ namespace ClientTests {
     public:
         ReIndex() : Base( "reindex" ) {}
         void run() {
+            OperationContextImpl txn;
+            DBDirectClient db(&txn);
 
             db.insert( ns() , BSON( "x" << 2 ) );
             ASSERT_EQUALS( 1 , db.getIndexes( ns() )->itcount() );
@@ -98,6 +107,8 @@ namespace ClientTests {
     public:
         ReIndex2() : Base( "reindex2" ) {}
         void run() {
+            OperationContextImpl txn;
+            DBDirectClient db(&txn);
 
             db.insert( ns() , BSON( "x" << 2 ) );
             ASSERT_EQUALS( 1 , db.getIndexes( ns() )->itcount() );
@@ -123,7 +134,9 @@ namespace ClientTests {
         BuildIndex() : Base("buildIndex") {}
         void run() {
             OperationContextImpl txn;
+
             Client::WriteContext ctx(&txn, ns());
+            DBDirectClient db(&txn);
 
             db.insert(ns(), BSON("x" << 1 << "y" << 2));
             db.insert(ns(), BSON("x" << 2 << "y" << 2));
@@ -158,9 +171,14 @@ namespace ClientTests {
     public:
         CS_10() : Base( "CS_10" ) {}
         void run() {
-            string longs( 770, 'c' );
-            for( int i = 0; i < 1111; ++i )
-                db.insert( ns(), BSON( "a" << i << "b" << longs ) );
+            OperationContextImpl txn;
+            DBDirectClient db(&txn);
+
+            const string longs( 770, 'c' );
+            for (int i = 0; i < 1111; ++i) {
+                db.insert(ns(), BSON("a" << i << "b" << longs));
+            }
+
             db.ensureIndex( ns(), BSON( "a" << 1 << "b" << 1 ) );
 
             auto_ptr< DBClientCursor > c = db.query( ns(), Query().sort( BSON( "a" << 1 << "b" << 1 ) ) );
@@ -172,8 +190,13 @@ namespace ClientTests {
     public:
         PushBack() : Base( "PushBack" ) {}
         void run() {
-            for( int i = 0; i < 10; ++i )
-                db.insert( ns(), BSON( "i" << i ) );
+            OperationContextImpl txn;
+            DBDirectClient db(&txn);
+
+            for (int i = 0; i < 10; ++i) {
+                db.insert(ns(), BSON("i" << i));
+            }
+
             auto_ptr< DBClientCursor > c = db.query( ns(), Query().sort( BSON( "i" << 1 ) ) );
 
             BSONObj o = c->next();
@@ -212,7 +235,10 @@ namespace ClientTests {
     public:
         Create() : Base( "Create" ) {}
         void run() {
-            db.createCollection( "unittests.clienttests.create", 4096, true );
+            OperationContextImpl txn;
+            DBDirectClient db(&txn);
+
+            db.createCollection("unittests.clienttests.create", 4096, true);
             BSONObj info;
             ASSERT( db.runCommand( "unittests", BSON( "collstats" << "clienttests.create" ), info ) );
         }
@@ -237,6 +263,7 @@ namespace ClientTests {
     class All : public Suite {
     public:
         All() : Suite( "client" ) {
+
         }
 
         void setupTests() {
diff --git a/src/mongo/dbtests/commandtests.cpp b/src/mongo/dbtests/commandtests.cpp
index a8aeb09bd6a..955620eac94 100644
--- a/src/mongo/dbtests/commandtests.cpp
+++ b/src/mongo/dbtests/commandtests.cpp
@@ -26,9 +26,10 @@
  *    then also delete it in the license file.
  */
 
-#include "mongo/pch.h"
+#include "mongo/platform/basic.h"
 
 #include "mongo/db/d_concurrency.h"
+#include "mongo/db/operation_context_impl.h"
 #include "mongo/dbtests/dbtests.h"
 
 using namespace mongo;
@@ -37,13 +38,14 @@ namespace CommandTests {
     // one namespace per command
     namespace FileMD5 {
         struct Base {
-            Base() {
+            Base() : db(&_txn) {
                 db.dropCollection(ns());
                 db.ensureIndex(ns(), BSON( "files_id" << 1 << "n" << 1 ));
             }
 
             const char* ns() { return "test.fs.chunks"; }
 
+            OperationContextImpl _txn;
             DBDirectClient db;
         };
         struct Type0 : Base {
diff --git a/src/mongo/dbtests/config_server_fixture.h b/src/mongo/dbtests/config_server_fixture.h
index 55c2d7f559f..f80565e1723 100644
--- a/src/mongo/dbtests/config_server_fixture.h
+++ b/src/mongo/dbtests/config_server_fixture.h
@@ -36,12 +36,18 @@
 
 namespace mongo {
 
+    class OperationContext;
+
     class CustomDirectClient: public DBDirectClient {
     public:
         CustomDirectClient() {
             setWireVersions(minWireVersion, maxWireVersion);
         }
 
+        CustomDirectClient(OperationContext* txn) : DBDirectClient(txn) {
+            setWireVersions(minWireVersion, maxWireVersion);
+        }
+
         virtual ConnectionString::ConnectionType type() const {
             return ConnectionString::CUSTOM;
         }
diff --git a/src/mongo/dbtests/counttests.cpp b/src/mongo/dbtests/counttests.cpp
index 8e34074e2aa..f8119b632a1 100644
--- a/src/mongo/dbtests/counttests.cpp
+++ b/src/mongo/dbtests/counttests.cpp
@@ -42,7 +42,7 @@ namespace CountTests {
 
     class Base {
     public:
-        Base() : lk(_txn.lockState(), ns()), _context( ns() ) {
+        Base() : lk(_txn.lockState(), ns()), _context(&_txn, ns()) {
             _database = _context.db();
             _collection = _database->getCollection( &_txn, ns() );
             if ( _collection ) {
diff --git a/src/mongo/dbtests/dbhelper_tests.cpp b/src/mongo/dbtests/dbhelper_tests.cpp
index e0aeb507e36..88c04aece66 100644
--- a/src/mongo/dbtests/dbhelper_tests.cpp
+++ b/src/mongo/dbtests/dbhelper_tests.cpp
@@ -61,7 +61,7 @@ namespace mongo {
             {
                 // Remove _id range [_min, _max).
                 Lock::DBWrite lk(txn.lockState(), ns);
-                Client::Context ctx( ns );
+                Client::Context ctx(&txn,  ns );
 
                 KeyRange range( ns,
                                 BSON( "_id" << _min ),
@@ -115,9 +115,8 @@ namespace mongo {
     //
 
     TEST(DBHelperTests, FindDiskLocs) {
-
-        DBDirectClient client;
         OperationContextImpl txn;
+        DBDirectClient client(&txn);
 
         // Some unique tag we can use to make sure we're pulling back the right data
         OID tag = OID::gen();
@@ -170,9 +169,8 @@ namespace mongo {
     //
 
     TEST(DBHelperTests, FindDiskLocsNoIndex) {
-
-        DBDirectClient client;
         OperationContextImpl txn;
+        DBDirectClient client(&txn);
 
         client.remove( ns, BSONObj() );
         client.insert( ns, BSON( "_id" << OID::gen() ) );
@@ -184,7 +182,7 @@ namespace mongo {
         long long estSizeBytes;
         {
             Lock::DBRead lk(txn.lockState(), ns);
-            Client::Context ctx( ns );
+            Client::Context ctx(&txn,  ns );
 
             // search invalid index range
             KeyRange range( ns,
@@ -212,9 +210,8 @@ namespace mongo {
     //
 
     TEST(DBHelperTests, FindDiskLocsTooBig) {
-
-        DBDirectClient client;
         OperationContextImpl txn;
+        DBDirectClient client(&txn);
 
         client.remove( ns, BSONObj() );
 
@@ -231,7 +228,7 @@ namespace mongo {
         long long estSizeBytes;
         {
             Lock::DBRead lk(txn.lockState(), ns);
-            Client::Context ctx( ns );
+            Client::Context ctx(&txn,  ns );
             KeyRange range( ns,
                             BSON( "_id" << 0 ),
                             BSON( "_id" << numDocsInserted ),
diff --git a/src/mongo/dbtests/directclienttests.cpp b/src/mongo/dbtests/directclienttests.cpp
index 0bea6ea2399..9c96dc331fd 100644
--- a/src/mongo/dbtests/directclienttests.cpp
+++ b/src/mongo/dbtests/directclienttests.cpp
@@ -35,6 +35,7 @@
 #include "mongo/db/instance.h"
 #include "mongo/db/json.h"
 #include "mongo/db/lasterror.h"
+#include "mongo/db/operation_context_impl.h"
 #include "mongo/dbtests/dbtests.h"
 #include "mongo/util/timer.h"
 
@@ -52,7 +53,8 @@ namespace DirectClientTests {
     class Capped : public ClientBase {
     public:
         virtual void run() {
-            DBDirectClient client;
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
             for( int pass=0; pass < 3; pass++ ) {
                 client.createCollection(ns, 1024 * 1024, true, 999);
                 for( int j =0; j < pass*3; j++ )
@@ -76,7 +78,9 @@ namespace DirectClientTests {
     class InsertMany : ClientBase {
     public:
         virtual void run(){
-            DBDirectClient client;
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             vector<BSONObj> objs;
             objs.push_back(BSON("_id" << 1));
             objs.push_back(BSON("_id" << 1));
@@ -99,7 +103,9 @@ namespace DirectClientTests {
     class BadNSCmd : ClientBase {
     public:
         virtual void run(){
-            DBDirectClient client;
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             BSONObj result;
             BSONObj cmdObj = BSON( "count" << "" );
             ASSERT_THROWS( client.runCommand( "", cmdObj, result ), UserException );
@@ -109,7 +115,9 @@ namespace DirectClientTests {
     class BadNSQuery : ClientBase {
     public:
         virtual void run(){
-            DBDirectClient client;
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             auto_ptr<DBClientCursor> cursor = client.query( "", Query(), 1 );
             ASSERT(cursor->more());
             BSONObj result = cursor->next().getOwned();
@@ -121,7 +129,9 @@ namespace DirectClientTests {
     class BadNSGetMore : ClientBase {
     public:
         virtual void run(){
-            DBDirectClient client;
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             auto_ptr<DBClientCursor> cursor = client.getMore("", 1, 1);
             ASSERT(cursor->more());
             BSONObj result = cursor->next().getOwned();
@@ -133,7 +143,9 @@ namespace DirectClientTests {
     class BadNSInsert : ClientBase {
     public:
         virtual void run(){
-            DBDirectClient client;
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             client.insert( "", BSONObj(), 0 );
             ASSERT( !client.getLastError().empty() );
         }
@@ -142,7 +154,9 @@ namespace DirectClientTests {
     class BadNSUpdate : ClientBase {
     public:
         virtual void run(){
-            DBDirectClient client;
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             client.update( "", Query(), BSON( "$set" << BSON( "x" << 1 )) );
             ASSERT( !client.getLastError().empty() );
         }
@@ -151,7 +165,9 @@ namespace DirectClientTests {
     class BadNSRemove : ClientBase {
     public:
         virtual void run(){
-            DBDirectClient client;
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             client.remove( "", Query() );
             ASSERT( !client.getLastError().empty() );
         }
diff --git a/src/mongo/dbtests/gle_test.cpp b/src/mongo/dbtests/gle_test.cpp
index 71b3642e3af..ded97a490e1 100644
--- a/src/mongo/dbtests/gle_test.cpp
+++ b/src/mongo/dbtests/gle_test.cpp
@@ -26,6 +26,7 @@
  *    then also delete it in the license file.
  */
 
+#include "mongo/db/operation_context_impl.h"
 #include "mongo/dbtests/dbtests.h"
 #include "mongo/util/assert_util.h"
 
@@ -43,7 +44,9 @@ namespace {
     class GetLastErrorCommandFailure {
     public:
         void run() {
-            DBDirectClient client;
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             client.insert(_ns, BSON( "test" << "test"));
 
             // Cannot mix fsync + j, will make command fail
@@ -58,7 +61,9 @@ namespace {
     class GetLastErrorClean {
     public:
         void run() {
-            DBDirectClient client;
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             client.insert(_ns, BSON( "test" << "test"));
 
             // Make sure there was no error
@@ -73,7 +78,9 @@ namespace {
     class GetLastErrorFromDup {
     public:
         void run() {
-            DBDirectClient client;
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             client.insert(_ns, BSON( "_id" << 1));
 
             // Make sure there was no error
diff --git a/src/mongo/dbtests/gridfstest.cpp b/src/mongo/dbtests/gridfstest.cpp
index 768db4cc307..14c861ca58e 100644
--- a/src/mongo/dbtests/gridfstest.cpp
+++ b/src/mongo/dbtests/gridfstest.cpp
@@ -29,6 +29,7 @@
 #include "mongo/pch.h"
 
 #include "mongo/client/gridfs.h"
+#include "mongo/db/operation_context_impl.h"
 #include "mongo/dbtests/dbtests.h"
 #include "mongo/util/assert_util.h"
 
@@ -41,7 +42,8 @@ namespace {
     class SetChunkSizeTest {
     public:
         virtual void run() {
-            DBDirectClient client;
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
 
             GridFS grid(client, "gridtest");
             grid.setChunkSize( 5 );
diff --git a/src/mongo/dbtests/jstests.cpp b/src/mongo/dbtests/jstests.cpp
index 400aceffd40..a5f8ff997b6 100644
--- a/src/mongo/dbtests/jstests.cpp
+++ b/src/mongo/dbtests/jstests.cpp
@@ -29,18 +29,20 @@
  *    then also delete it in the license file.
  */
 
-#include "mongo/pch.h"
+#include "mongo/platform/basic.h"
 
 #include <limits>
 
 #include "mongo/base/parse_number.h"
 #include "mongo/db/instance.h"
 #include "mongo/db/json.h"
+#include "mongo/db/operation_context_impl.h"
 #include "mongo/db/storage_options.h"
 #include "mongo/dbtests/dbtests.h"
 #include "mongo/scripting/engine.h"
 #include "mongo/util/timer.h"
 
+
 namespace mongo {
     bool dbEval(const string& dbName , BSONObj& cmd, BSONObjBuilder& result, string& errmsg);
 } // namespace mongo
@@ -916,6 +918,10 @@ namespace JSTests {
             }
             string utf8ObjSpec = "{'_id':'\\u0001\\u007f\\u07ff\\uffff'}";
             BSONObj utf8Obj = fromjson( utf8ObjSpec );
+
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             client.insert( ns(), utf8Obj );
             client.eval( "unittest", "v = db.jstests.utf8check.findOne(); db.jstests.utf8check.remove( {} ); db.jstests.utf8check.insert( v );" );
             check( utf8Obj, client.findOne( ns(), BSONObj() ) );
@@ -927,12 +933,15 @@ namespace JSTests {
                 FAIL( fail.c_str() );
             }
         }
+
         void reset() {
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             client.dropCollection( ns() );
         }
-        static const char *ns() { return "unittest.jstests.utf8check"; }
 
-        DBDirectClient client;
+        static const char *ns() { return "unittest.jstests.utf8check"; }
     };
 
     class LongUtf8String {
@@ -942,15 +951,21 @@ namespace JSTests {
         void run() {
             if( !globalScriptEngine->utf8Ok() )
                 return;
+
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             client.eval( "unittest", "db.jstests.longutf8string.save( {_id:'\\uffff\\uffff\\uffff\\uffff'} )" );
         }
     private:
         void reset() {
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             client.dropCollection( ns() );
         }
-        static const char *ns() { return "unittest.jstests.longutf8string"; }
 
-        DBDirectClient client;
+        static const char *ns() { return "unittest.jstests.longutf8string"; }
     };
 
     class InvalidUTF8Check {
@@ -1021,10 +1036,12 @@ namespace JSTests {
         public:
             virtual ~TestRoundTrip() {}
             void run() {
-
                 // Insert in Javascript -> Find using DBDirectClient
 
                 // Drop the collection
+                OperationContextImpl txn;
+                DBDirectClient client(&txn);
+
                 client.dropCollection( "unittest.testroundtrip" );
 
                 // Insert in Javascript
@@ -1080,8 +1097,6 @@ namespace JSTests {
             virtual string jsonOut() const {
                 return json();
             }
-
-            DBDirectClient client;
         };
 
         class DBRefTest : public TestRoundTrip {
@@ -1993,7 +2008,9 @@ namespace JSTests {
             update.append( "_id" , "invalidstoredjs1" );
             update.appendCode( "value" , "function () { db.test.find().forEach(function(obj) { continue; }); }" );
 
-            DBDirectClient client;
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             client.update( "test.system.js" , query.obj() , update.obj() , true /* upsert */ );
 
             scoped_ptr<Scope> s( globalScriptEngine->newScope() );
diff --git a/src/mongo/dbtests/matchertests.cpp b/src/mongo/dbtests/matchertests.cpp
index 67bff7ef74b..cee3995395c 100644
--- a/src/mongo/dbtests/matchertests.cpp
+++ b/src/mongo/dbtests/matchertests.cpp
@@ -41,18 +41,19 @@ namespace MatcherTests {
 
     class CollectionBase {
     public:
-        CollectionBase() :
-        _ns( "unittests.matchertests" ) {
+        CollectionBase() : _ns( "unittests.matchertests" ) {
+
         }
+
         virtual ~CollectionBase() {
-            client().dropCollection( ns() );
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
+            client.dropCollection(_ns);
         }
+
     protected:
-        const char* ns() const { return _ns; }
-        DBDirectClient &client() { return _client; }
-    private:
         const char * const _ns;
-        DBDirectClient _client;
     };
 
     template <typename M>
diff --git a/src/mongo/dbtests/oplogstarttests.cpp b/src/mongo/dbtests/oplogstarttests.cpp
index a0c94493fbc..45015afe883 100644
--- a/src/mongo/dbtests/oplogstarttests.cpp
+++ b/src/mongo/dbtests/oplogstarttests.cpp
@@ -38,7 +38,8 @@ namespace OplogStartTests {
     class Base {
     public:
         Base() : _lk(_txn.lockState()),
-                 _context(ns()) {
+                 _context(&_txn, ns()),
+                 _client(&_txn) {
 
             Collection* c = _context.db()->getCollection(&_txn, ns());
             if (!c) {
diff --git a/src/mongo/dbtests/pdfiletests.cpp b/src/mongo/dbtests/pdfiletests.cpp
index 10d4e01d1fd..d954c801fdd 100644
--- a/src/mongo/dbtests/pdfiletests.cpp
+++ b/src/mongo/dbtests/pdfiletests.cpp
@@ -48,7 +48,7 @@ namespace PdfileTests {
         class Base {
         public:
             Base() : _lk(_txn.lockState()),
-                     _context(ns()) {
+                     _context(&_txn, ns()) {
 
             }
 
diff --git a/src/mongo/dbtests/perf/perftest.cpp b/src/mongo/dbtests/perf/perftest.cpp
index 2afa74f68fa..6ae7cf35532 100644
--- a/src/mongo/dbtests/perf/perftest.cpp
+++ b/src/mongo/dbtests/perf/perftest.cpp
@@ -702,7 +702,7 @@ namespace Plan {
             lk_.reset( new Lock::GlobalWrite );
         }
         void run() {
-            Client::Context ctx( ns_ );
+            Client::Context ctx(txn,  ns_ );
             for( int i = 0; i < 10000; ++i ) {
                 scoped_ptr<MultiPlanScanner> s
                         ( MultiPlanScanner::make( ns_.c_str(), BSONObj(), BSON( "a" << 1 ) ) );
@@ -723,7 +723,7 @@ namespace Plan {
             lk_.reset( new Lock::GlobalWrite );
         }
         void run() {
-            Client::Context ctx( ns_.c_str() );
+            Client::Context ctx(txn,  ns_.c_str() );
             for( int i = 0; i < 10000; ++i ) {
                 scoped_ptr<MultiPlanScanner>
                         s( MultiPlanScanner::make( ns_.c_str(), BSON( "a" << 1 ), BSONObj() ) );
diff --git a/src/mongo/dbtests/perftests.cpp b/src/mongo/dbtests/perftests.cpp
index 74eb31e8f68..3536b8ec07e 100644
--- a/src/mongo/dbtests/perftests.cpp
+++ b/src/mongo/dbtests/perftests.cpp
@@ -41,6 +41,7 @@
 #include <fstream>
 
 #include "mongo/db/db.h"
+#include "mongo/db/operation_context_impl.h"
 #include "mongo/db/storage/mmap_v1/durable_mapped_file.h"
 #include "mongo/db/storage/mmap_v1/dur_stats.h"
 #include "mongo/db/instance.h"
@@ -71,8 +72,8 @@ namespace PerfTests {
     class ClientBase {
     public:
         // NOTE: Not bothering to backup the old error record.
-        ClientBase() {
-            mongo::lastError.reset( new LastError() );
+        ClientBase() : _client(&_txn) {
+            mongo::lastError.reset(new LastError());
         }
         virtual ~ClientBase() {
 
@@ -91,6 +92,7 @@ namespace PerfTests {
         DBClientBase* client() { return &_client; }
 
     private:
+        OperationContextImpl _txn;
         DBDirectClient _client;
     };
 
@@ -356,7 +358,9 @@ namespace PerfTests {
             static int z;
             srand( ++z ^ (unsigned) time(0));
 #endif
-            DBDirectClient c;
+            OperationContextImpl txn;
+            DBDirectClient c(&txn);
+
             Client::initThreadIfNotAlready("perftestthr");
             const unsigned int Batch = batchSize();
             while( 1 ) {
diff --git a/src/mongo/dbtests/plan_ranking.cpp b/src/mongo/dbtests/plan_ranking.cpp
index 240371f1482..79419bb60fa 100644
--- a/src/mongo/dbtests/plan_ranking.cpp
+++ b/src/mongo/dbtests/plan_ranking.cpp
@@ -60,7 +60,10 @@ namespace PlanRankingTests {
 
     class PlanRankingTestBase {
     public:
-        PlanRankingTestBase() : _internalQueryForceIntersectionPlans(internalQueryForceIntersectionPlans) {
+        PlanRankingTestBase()
+            : _internalQueryForceIntersectionPlans(internalQueryForceIntersectionPlans),
+              _client(&_txn) {
+
             Client::WriteContext ctx(&_txn, ns);
             _client.dropCollection(ns);
         }
@@ -140,12 +143,13 @@ namespace PlanRankingTests {
         OperationContextImpl _txn;
 
     private:
-
-        DBDirectClient _client;
-        scoped_ptr<MultiPlanStage> _mps;
         // Holds the value of global "internalQueryForceIntersectionPlans" setParameter flag.
         // Restored at end of test invocation regardless of test result.
         bool _internalQueryForceIntersectionPlans;
+
+        scoped_ptr<MultiPlanStage> _mps;
+
+        DBDirectClient _client;
     };
 
     // static
diff --git a/src/mongo/dbtests/profile_test.cpp b/src/mongo/dbtests/profile_test.cpp
index b7a58b856d4..15e04854bf2 100644
--- a/src/mongo/dbtests/profile_test.cpp
+++ b/src/mongo/dbtests/profile_test.cpp
@@ -31,6 +31,7 @@
  */
 
 #include "mongo/db/instance.h"
+#include "mongo/db/operation_context_impl.h"
 #include "mongo/unittest/unittest.h"
 
 using mongo::BSONObj;
@@ -38,7 +39,8 @@ using mongo::DBDirectClient;
 
 using std::string;
 
-namespace mongo_test {
+namespace mongo {
+
     class Profiler: public mongo::unittest::Test {
     public:
         static const string PROFILER_TEST_DB;
@@ -48,11 +50,13 @@ namespace mongo_test {
     protected:
         void setUp() {
             BSONObj ret;
+
+            OperationContextImpl txn;
+            DBDirectClient db(&txn);
+
             db.runCommand(PROFILER_TEST_DB, BSON("dropDatabase" << 1), ret);
             ASSERT(ret["ok"].trueValue());
         }
-
-        DBDirectClient db;
     };
 
     const string Profiler::PROFILER_TEST_DB = "profilerTestDB";
@@ -64,6 +68,9 @@ namespace mongo_test {
         // be profiled in a shortened version
         const string bigStr(16 * (1 << 20) - 200, 'a');
 
+        OperationContextImpl txn;
+        DBDirectClient db(&txn);
+
         {
             BSONObj replyObj;
             db.runCommand(PROFILER_TEST_DB, BSON("profile" << 2), replyObj);
@@ -95,7 +102,8 @@ namespace mongo_test {
             builder.append(fieldName, x);
         }
 
-        DBDirectClient db;
+        OperationContextImpl txn;
+        DBDirectClient db(&txn);
 
         {
             BSONObj replyObj;
diff --git a/src/mongo/dbtests/query_multi_plan_runner.cpp b/src/mongo/dbtests/query_multi_plan_runner.cpp
index 8ca3b5a248c..f47d08ecfe8 100644
--- a/src/mongo/dbtests/query_multi_plan_runner.cpp
+++ b/src/mongo/dbtests/query_multi_plan_runner.cpp
@@ -57,7 +57,9 @@ namespace QueryMultiPlanRunner {
 
     class MultiPlanRunnerBase {
     public:
-        MultiPlanRunnerBase() { }
+        MultiPlanRunnerBase() : _client(&_txn) {
+
+        }
 
         virtual ~MultiPlanRunnerBase() {
             _client.dropCollection(ns());
@@ -82,7 +84,8 @@ namespace QueryMultiPlanRunner {
 
         static const char* ns() { return "unittests.QueryStageMultiPlanRunner"; }
 
-    private:
+    protected:
+        OperationContextImpl _txn;
         DBDirectClient _client;
     };
 
@@ -92,8 +95,7 @@ namespace QueryMultiPlanRunner {
     class MPRCollectionScanVsHighlySelectiveIXScan : public MultiPlanRunnerBase {
     public:
         void run() {
-            OperationContextImpl txn;
-            Client::WriteContext ctx(&txn, ns());
+            Client::WriteContext ctx(&_txn, ns());
 
             const int N = 5000;
             for (int i = 0; i < N; ++i) {
@@ -106,14 +108,14 @@ namespace QueryMultiPlanRunner {
             // Every call to work() returns something so this should clearly win (by current scoring
             // at least).
             IndexScanParams ixparams;
-            ixparams.descriptor = getIndex(&txn, ctx.ctx().db(), BSON("foo" << 1));
+            ixparams.descriptor = getIndex(&_txn, ctx.ctx().db(), BSON("foo" << 1));
             ixparams.bounds.isSimpleRange = true;
             ixparams.bounds.startKey = BSON("" << 7);
             ixparams.bounds.endKey = BSON("" << 7);
             ixparams.bounds.endKeyInclusive = true;
             ixparams.direction = 1;
 
-            const Collection* coll = ctx.ctx().db()->getCollection(&txn, ns());
+            const Collection* coll = ctx.ctx().db()->getCollection(&_txn, ns());
 
             auto_ptr<WorkingSet> sharedWs(new WorkingSet());
             IndexScan* ix = new IndexScan(ixparams, sharedWs.get(), NULL);
@@ -121,7 +123,7 @@ namespace QueryMultiPlanRunner {
 
             // Plan 1: CollScan with matcher.
             CollectionScanParams csparams;
-            csparams.collection = ctx.ctx().db()->getCollection( &txn, ns() );
+            csparams.collection = ctx.ctx().db()->getCollection( &_txn, ns() );
             csparams.direction = CollectionScanParams::FORWARD;
 
             // Make the filter.
@@ -138,7 +140,7 @@ namespace QueryMultiPlanRunner {
             verify(CanonicalQuery::canonicalize(ns(), BSON("foo" << 7), &cq).isOK());
             verify(NULL != cq);
 
-            MultiPlanStage* mps = new MultiPlanStage(ctx.ctx().db()->getCollection(&txn, ns()),cq);
+            MultiPlanStage* mps = new MultiPlanStage(ctx.ctx().db()->getCollection(&_txn, ns()),cq);
             mps->addPlan(createQuerySolution(), firstRoot.release(), sharedWs.get());
             mps->addPlan(createQuerySolution(), secondRoot.release(), sharedWs.get());
 
@@ -148,7 +150,7 @@ namespace QueryMultiPlanRunner {
             ASSERT_EQUALS(0, mps->bestPlanIdx());
 
             SingleSolutionRunner sr(
-                ctx.ctx().db()->getCollection(&txn, ns()),
+                ctx.ctx().db()->getCollection(&_txn, ns()),
                 cq,
                 mps->bestSolution(),
                 mps,
diff --git a/src/mongo/dbtests/query_single_solution_runner.cpp b/src/mongo/dbtests/query_single_solution_runner.cpp
index 246cf66df1a..d5290853151 100644
--- a/src/mongo/dbtests/query_single_solution_runner.cpp
+++ b/src/mongo/dbtests/query_single_solution_runner.cpp
@@ -45,7 +45,9 @@ namespace QuerySingleSolutionRunner {
 
     class SingleSolutionRunnerBase {
     public:
-        SingleSolutionRunnerBase() { }
+        SingleSolutionRunnerBase() : _client(&_txn) {
+        
+        }
 
         virtual ~SingleSolutionRunnerBase() {
             _client.dropCollection(ns());
diff --git a/src/mongo/dbtests/query_stage_and.cpp b/src/mongo/dbtests/query_stage_and.cpp
index ab7ff6a5457..59a5ae3819f 100644
--- a/src/mongo/dbtests/query_stage_and.cpp
+++ b/src/mongo/dbtests/query_stage_and.cpp
@@ -51,7 +51,9 @@ namespace QueryStageAnd {
 
     class QueryStageAndBase {
     public:
-        QueryStageAndBase() { }
+        QueryStageAndBase() : _client(&_txn) { 
+
+        }
 
         virtual ~QueryStageAndBase() {
             _client.dropCollection(ns());
diff --git a/src/mongo/dbtests/query_stage_collscan.cpp b/src/mongo/dbtests/query_stage_collscan.cpp
index 20fb3ad5b62..647b721f878 100644
--- a/src/mongo/dbtests/query_stage_collscan.cpp
+++ b/src/mongo/dbtests/query_stage_collscan.cpp
@@ -313,7 +313,7 @@ namespace QueryStageCollectionScan {
 
     class QueryStageCollectionScanBase {
     public:
-        QueryStageCollectionScanBase() {
+        QueryStageCollectionScanBase() : _client(&_txn) {
             Client::WriteContext ctx(&_txn, ns());
 
             for (int i = 0; i < numObj(); ++i) {
diff --git a/src/mongo/dbtests/query_stage_count.cpp b/src/mongo/dbtests/query_stage_count.cpp
index eaecb772981..04a45d98044 100644
--- a/src/mongo/dbtests/query_stage_count.cpp
+++ b/src/mongo/dbtests/query_stage_count.cpp
@@ -48,7 +48,9 @@ namespace QueryStageCount {
 
     class CountBase {
     public:
-        CountBase() { }
+        CountBase() : _client(&_txn) {
+        
+        }
 
         virtual ~CountBase() {
             Client::WriteContext ctx(&_txn, ns());
diff --git a/src/mongo/dbtests/query_stage_distinct.cpp b/src/mongo/dbtests/query_stage_distinct.cpp
index c8799f73fcb..942c87b264a 100644
--- a/src/mongo/dbtests/query_stage_distinct.cpp
+++ b/src/mongo/dbtests/query_stage_distinct.cpp
@@ -46,7 +46,9 @@ namespace QueryStageDistinct {
 
     class DistinctBase {
     public:
-        DistinctBase() { }
+        DistinctBase() : _client(&_txn) { 
+
+        }
 
         virtual ~DistinctBase() {
             Client::WriteContext ctx(&_txn, ns());
diff --git a/src/mongo/dbtests/query_stage_fetch.cpp b/src/mongo/dbtests/query_stage_fetch.cpp
index 3414475baf9..4bea8b9e004 100644
--- a/src/mongo/dbtests/query_stage_fetch.cpp
+++ b/src/mongo/dbtests/query_stage_fetch.cpp
@@ -48,7 +48,9 @@ namespace QueryStageFetch {
 
     class QueryStageFetchBase {
     public:
-        QueryStageFetchBase() { }
+        QueryStageFetchBase() : _client(&_txn) {
+        
+        }
 
         virtual ~QueryStageFetchBase() {
             _client.dropCollection(ns());
@@ -75,6 +77,7 @@ namespace QueryStageFetch {
         static const char* ns() { return "unittests.QueryStageFetch"; }
 
     private:
+        OperationContextImpl _txn;
         DBDirectClient _client;
     };
 
diff --git a/src/mongo/dbtests/query_stage_keep.cpp b/src/mongo/dbtests/query_stage_keep.cpp
index 3be756ae2a5..3283b66ab8c 100644
--- a/src/mongo/dbtests/query_stage_keep.cpp
+++ b/src/mongo/dbtests/query_stage_keep.cpp
@@ -52,7 +52,9 @@ namespace QueryStageKeep {
 
     class QueryStageKeepBase {
     public:
-        QueryStageKeepBase() { }
+        QueryStageKeepBase() : _client(&_txn) {
+        
+        }
 
         virtual ~QueryStageKeepBase() {
             _client.dropCollection(ns());
@@ -89,7 +91,8 @@ namespace QueryStageKeep {
             return WorkingSet::INVALID_ID;
         }
 
-    private:
+    protected:
+        OperationContextImpl _txn;
         DBDirectClient _client;
     };
 
@@ -102,13 +105,12 @@ namespace QueryStageKeep {
     class KeepStageBasic : public QueryStageKeepBase {
     public:
         void run() {
-            OperationContextImpl txn;
-            Client::WriteContext ctx(&txn, ns());
+            Client::WriteContext ctx(&_txn, ns());
 
             Database* db = ctx.ctx().db();
-            Collection* coll = db->getCollection(&txn, ns());
+            Collection* coll = db->getCollection(&_txn, ns());
             if (!coll) {
-                coll = db->createCollection(&txn, ns());
+                coll = db->createCollection(&_txn, ns());
             }
             WorkingSet ws;
 
diff --git a/src/mongo/dbtests/query_stage_merge_sort.cpp b/src/mongo/dbtests/query_stage_merge_sort.cpp
index ff52f9c6ffc..11161a5c6be 100644
--- a/src/mongo/dbtests/query_stage_merge_sort.cpp
+++ b/src/mongo/dbtests/query_stage_merge_sort.cpp
@@ -47,7 +47,9 @@ namespace QueryStageMergeSortTests {
 
     class QueryStageMergeSortTestBase {
     public:
-        QueryStageMergeSortTestBase() { }
+        QueryStageMergeSortTestBase() : _client(&_txn) {
+        
+        }
 
         virtual ~QueryStageMergeSortTestBase() {
             Client::WriteContext ctx(&_txn, ns());
@@ -109,9 +111,8 @@ namespace QueryStageMergeSortTests {
     public:
         void run() {
             Client::WriteContext ctx(&_txn, ns());
-            OperationContextImpl txn;
             Database* db = ctx.ctx().db();
-            Collection* coll = db->getCollection(&txn, ns());
+            Collection* coll = db->getCollection(&_txn, ns());
             if (!coll) {
                 coll = db->createCollection(&_txn, ns());
             }
@@ -173,9 +174,8 @@ namespace QueryStageMergeSortTests {
     public:
         void run() {
             Client::WriteContext ctx(&_txn, ns());
-            OperationContextImpl txn;
             Database* db = ctx.ctx().db();
-            Collection* coll = db->getCollection(&txn, ns());
+            Collection* coll = db->getCollection(&_txn, ns());
             if (!coll) {
                 coll = db->createCollection(&_txn, ns());
             }
@@ -236,9 +236,8 @@ namespace QueryStageMergeSortTests {
     public:
         void run() {
             Client::WriteContext ctx(&_txn, ns());
-            OperationContextImpl txn;
             Database* db = ctx.ctx().db();
-            Collection* coll = db->getCollection(&txn, ns());
+            Collection* coll = db->getCollection(&_txn, ns());
             if (!coll) {
                 coll = db->createCollection(&_txn, ns());
             }
@@ -300,9 +299,8 @@ namespace QueryStageMergeSortTests {
     public:
         void run() {
             Client::WriteContext ctx(&_txn, ns());
-            OperationContextImpl txn;
             Database* db = ctx.ctx().db();
-            Collection* coll = db->getCollection(&txn, ns());
+            Collection* coll = db->getCollection(&_txn, ns());
             if (!coll) {
                 coll = db->createCollection(&_txn, ns());
             }
@@ -365,9 +363,8 @@ namespace QueryStageMergeSortTests {
     public:
         void run() {
             Client::WriteContext ctx(&_txn, ns());
-            OperationContextImpl txn;
             Database* db = ctx.ctx().db();
-            Collection* coll = db->getCollection(&txn, ns());
+            Collection* coll = db->getCollection(&_txn, ns());
             if (!coll) {
                 coll = db->createCollection(&_txn, ns());
             }
@@ -428,9 +425,8 @@ namespace QueryStageMergeSortTests {
     public:
         void run() {
             Client::WriteContext ctx(&_txn, ns());
-            OperationContextImpl txn;
             Database* db = ctx.ctx().db();
-            Collection* coll = db->getCollection(&txn, ns());
+            Collection* coll = db->getCollection(&_txn, ns());
             if (!coll) {
                 coll = db->createCollection(&_txn, ns());
             }
@@ -481,9 +477,8 @@ namespace QueryStageMergeSortTests {
     public:
         void run() {
             Client::WriteContext ctx(&_txn, ns());
-            OperationContextImpl txn;
             Database* db = ctx.ctx().db();
-            Collection* coll = db->getCollection(&txn, ns());
+            Collection* coll = db->getCollection(&_txn, ns());
             if (!coll) {
                 coll = db->createCollection(&_txn, ns());
             }
diff --git a/src/mongo/dbtests/query_stage_sort.cpp b/src/mongo/dbtests/query_stage_sort.cpp
index 1d9b4806db3..6ae66a0b7bb 100644
--- a/src/mongo/dbtests/query_stage_sort.cpp
+++ b/src/mongo/dbtests/query_stage_sort.cpp
@@ -47,7 +47,9 @@ namespace QueryStageSortTests {
 
     class QueryStageSortTestBase {
     public:
-        QueryStageSortTestBase() { }
+        QueryStageSortTestBase() : _client(&_txn) {
+        
+        }
 
         void fillData() {
             for (int i = 0; i < numObj(); ++i) {
@@ -168,7 +170,9 @@ namespace QueryStageSortTests {
 
 
         static const char* ns() { return "unittests.QueryStageSort"; }
-    private:
+
+    protected:
+        OperationContextImpl _txn;
         DBDirectClient _client;
     };
 
@@ -179,13 +183,12 @@ namespace QueryStageSortTests {
         virtual int numObj() { return 100; }
 
         void run() {
-            OperationContextImpl txn;
-            Client::WriteContext ctx(&txn, ns());
+            Client::WriteContext ctx(&_txn, ns());
 
             Database* db = ctx.ctx().db();
-            Collection* coll = db->getCollection(&txn, ns());
+            Collection* coll = db->getCollection(&_txn, ns());
             if (!coll) {
-                coll = db->createCollection(&txn, ns());
+                coll = db->createCollection(&_txn, ns());
             }
 
             fillData();
@@ -199,13 +202,12 @@ namespace QueryStageSortTests {
         virtual int numObj() { return 100; }
 
         void run() {
-            OperationContextImpl txn;
-            Client::WriteContext ctx(&txn, ns());
+            Client::WriteContext ctx(&_txn, ns());
 
             Database* db = ctx.ctx().db();
-            Collection* coll = db->getCollection(&txn, ns());
+            Collection* coll = db->getCollection(&_txn, ns());
             if (!coll) {
-                coll = db->createCollection(&txn, ns());
+                coll = db->createCollection(&_txn, ns());
             }
 
             fillData();
@@ -228,13 +230,12 @@ namespace QueryStageSortTests {
         virtual int numObj() { return 10000; }
 
         void run() {
-            OperationContextImpl txn;
-            Client::WriteContext ctx(&txn, ns());
+            Client::WriteContext ctx(&_txn, ns());
 
             Database* db = ctx.ctx().db();
-            Collection* coll = db->getCollection(&txn, ns());
+            Collection* coll = db->getCollection(&_txn, ns());
             if (!coll) {
-                coll = db->createCollection(&txn, ns());
+                coll = db->createCollection(&_txn, ns());
             }
 
             fillData();
@@ -248,13 +249,12 @@ namespace QueryStageSortTests {
         virtual int numObj() { return 2000; }
 
         void run() {
-            OperationContextImpl txn;
-            Client::WriteContext ctx(&txn, ns());
+            Client::WriteContext ctx(&_txn, ns());
             
             Database* db = ctx.ctx().db();
-            Collection* coll = db->getCollection(&txn, ns());
+            Collection* coll = db->getCollection(&_txn, ns());
             if (!coll) {
-                coll = db->createCollection(&txn, ns());
+                coll = db->createCollection(&_txn, ns());
             }
             fillData();
 
@@ -339,13 +339,12 @@ namespace QueryStageSortTests {
         virtual int numObj() { return 100; }
 
         void run() {
-            OperationContextImpl txn;
-            Client::WriteContext ctx(&txn, ns());
+            Client::WriteContext ctx(&_txn, ns());
             
             Database* db = ctx.ctx().db();
-            Collection* coll = db->getCollection(&txn, ns());
+            Collection* coll = db->getCollection(&_txn, ns());
             if (!coll) {
-                coll = db->createCollection(&txn, ns());
+                coll = db->createCollection(&_txn, ns());
             }
 
             WorkingSet* ws = new WorkingSet();
diff --git a/src/mongo/dbtests/query_stage_tests.cpp b/src/mongo/dbtests/query_stage_tests.cpp
index 23525ca265d..fc5ee43ea50 100644
--- a/src/mongo/dbtests/query_stage_tests.cpp
+++ b/src/mongo/dbtests/query_stage_tests.cpp
@@ -46,7 +46,7 @@ namespace QueryStageTests {
 
     class IndexScanBase {
     public:
-        IndexScanBase() {
+        IndexScanBase() : _client(&_txn) {
             Client::WriteContext ctx(&_txn, ns());
 
             for (int i = 0; i < numObj(); ++i) {
diff --git a/src/mongo/dbtests/querytests.cpp b/src/mongo/dbtests/querytests.cpp
index ac70e48555f..ef3d859a260 100644
--- a/src/mongo/dbtests/querytests.cpp
+++ b/src/mongo/dbtests/querytests.cpp
@@ -65,7 +65,7 @@ namespace QueryTests {
 
     public:
         Base() : _lk(_txn.lockState()),
-                 _context(ns()) {
+                 _context(&_txn, ns()) {
 
             _database = _context.db();
             _collection = _database->getCollection( &_txn, ns() );
@@ -162,7 +162,7 @@ namespace QueryTests {
             // We don't normally allow empty objects in the database, but test that we can find
             // an empty object (one might be allowed inside a reserved namespace at some point).
             Lock::GlobalWrite lk(_txn.lockState());
-            Client::Context ctx( "unittests.querytests" );
+            Client::Context ctx(&_txn,  "unittests.querytests" );
 
             Database* db = ctx.db();
             if ( db->getCollection( &_txn, ns() ) ) {
@@ -172,7 +172,7 @@ namespace QueryTests {
             _collection = db->createCollection( &_txn, ns(), CollectionOptions(), true, false );
             ASSERT( _collection );
 
-            DBDirectClient cl;
+            DBDirectClient cl(&_txn);
             BSONObj info;
             bool ok = cl.runCommand( "unittests", BSON( "godinsert" << "querytests" << "obj" << BSONObj() ), info );
             ASSERT( ok );
@@ -188,7 +188,7 @@ namespace QueryTests {
     
     class ClientBase {
     public:
-        ClientBase() {
+        ClientBase() : _client(&_txn) {
             mongo::lastError.reset( new LastError() );
         }
         ~ClientBase() {
@@ -197,27 +197,23 @@ namespace QueryTests {
 
     protected:
         void insert( const char *ns, BSONObj o ) {
-            client_.insert( ns, o );
+            _client.insert( ns, o );
         }
         void update( const char *ns, BSONObj q, BSONObj o, bool upsert = 0 ) {
-            client_.update( ns, Query( q ), o, upsert );
+            _client.update( ns, Query( q ), o, upsert );
         }
         bool error() {
-            return !client_.getPrevError().getField( "err" ).isNull();
+            return !_client.getPrevError().getField( "err" ).isNull();
         }
 
-        const DBDirectClient& client() const { return client_; }
-        DBDirectClient& client() { return client_; }
-
-        DBDirectClient client_;
-
         OperationContextImpl _txn;
+        DBDirectClient _client;
     };
 
     class BoundedKey : public ClientBase {
     public:
         ~BoundedKey() {
-            client().dropCollection( "unittests.querytests.BoundedKey" );
+            _client.dropCollection( "unittests.querytests.BoundedKey" );
         }
         void run() {
             const char *ns = "unittests.querytests.BoundedKey";
@@ -225,23 +221,23 @@ namespace QueryTests {
             BSONObjBuilder a;
             a.appendMaxKey( "$lt" );
             BSONObj limit = a.done();
-            ASSERT( !client().findOne( ns, QUERY( "a" << limit ) ).isEmpty() );
-            client().ensureIndex( ns, BSON( "a" << 1 ) );
-            ASSERT( !client().findOne( ns, QUERY( "a" << limit ).hint( BSON( "a" << 1 ) ) ).isEmpty() );
+            ASSERT( !_client.findOne( ns, QUERY( "a" << limit ) ).isEmpty() );
+            _client.ensureIndex( ns, BSON( "a" << 1 ) );
+            ASSERT( !_client.findOne( ns, QUERY( "a" << limit ).hint( BSON( "a" << 1 ) ) ).isEmpty() );
         }
     };
 
     class GetMore : public ClientBase {
     public:
         ~GetMore() {
-            client().dropCollection( "unittests.querytests.GetMore" );
+            _client.dropCollection( "unittests.querytests.GetMore" );
         }
         void run() {
             const char *ns = "unittests.querytests.GetMore";
             insert( ns, BSON( "a" << 1 ) );
             insert( ns, BSON( "a" << 2 ) );
             insert( ns, BSON( "a" << 3 ) );
-            auto_ptr< DBClientCursor > cursor = client().query( ns, BSONObj(), 2 );
+            auto_ptr< DBClientCursor > cursor = _client.query( ns, BSONObj(), 2 );
             long long cursorId = cursor->getCursorId();
             cursor->decouple();
             cursor.reset();
@@ -249,7 +245,7 @@ namespace QueryTests {
             {
                 // Check internal server handoff to getmore.
                 Lock::DBWrite lk(_txn.lockState(), ns);
-                Client::Context ctx( ns );
+                Client::Context ctx(&_txn,  ns );
                 ClientCursorPin clientCursor( ctx.db()->getCollection(&_txn, ns), cursorId );
                 // pq doesn't exist if it's a runner inside of the clientcursor.
                 // ASSERT( clientCursor.c()->pq );
@@ -257,7 +253,7 @@ namespace QueryTests {
                 ASSERT_EQUALS( 2, clientCursor.c()->pos() );
             }
             
-            cursor = client().getMore( ns, cursorId );
+            cursor = _client.getMore( ns, cursorId );
             ASSERT( cursor->more() );
             ASSERT_EQUALS( 3, cursor->next().getIntField( "a" ) );
         }
@@ -274,7 +270,7 @@ namespace QueryTests {
     public:
         ~GetMoreKillOp() {
             getGlobalEnvironment()->unsetKillAllOperations();
-            client().dropCollection( "unittests.querytests.GetMoreKillOp" );
+            _client.dropCollection( "unittests.querytests.GetMoreKillOp" );
         }
         void run() {
             
@@ -285,7 +281,7 @@ namespace QueryTests {
             }
 
             // Create a cursor on the collection, with a batch size of 200.
-            auto_ptr<DBClientCursor> cursor = client().query( ns, "", 0, 0, 0, 0, 200 );
+            auto_ptr<DBClientCursor> cursor = _client.query( ns, "", 0, 0, 0, 0, 200 );
             CursorId cursorId = cursor->getCursorId();
             
             // Count 500 results, spanning a few batches of documents.
@@ -313,7 +309,7 @@ namespace QueryTests {
             ASSERT_FALSE(CollectionCursorCache::eraseCursorGlobal(&_txn, cursorId));
 
             // Check that a subsequent get more fails with the cursor removed.
-            ASSERT_THROWS( client().getMore( ns, cursorId ), UserException );
+            ASSERT_THROWS( _client.getMore( ns, cursorId ), UserException );
         }
     };
 
@@ -326,7 +322,7 @@ namespace QueryTests {
     public:
         ~GetMoreInvalidRequest() {
             getGlobalEnvironment()->unsetKillAllOperations();
-            client().dropCollection( "unittests.querytests.GetMoreInvalidRequest" );
+            _client.dropCollection( "unittests.querytests.GetMoreInvalidRequest" );
         }
         void run() {
 
@@ -337,7 +333,7 @@ namespace QueryTests {
             }
             
             // Create a cursor on the collection, with a batch size of 200.
-            auto_ptr<DBClientCursor> cursor = client().query( ns, "", 0, 0, 0, 0, 200 );
+            auto_ptr<DBClientCursor> cursor = _client.query( ns, "", 0, 0, 0, 0, 200 );
             CursorId cursorId = cursor->getCursorId();
 
             // Count 500 results, spanning a few batches of documents.
@@ -350,7 +346,7 @@ namespace QueryTests {
 
             // Send a get more with a namespace that is incorrect ('spoofed') for this cursor id.
             // This is the invalaid get more request described in the comment preceding this class.
-            client().getMore
+            _client.getMore
                     ( "unittests.querytests.GetMoreInvalidRequest_WRONG_NAMESPACE_FOR_CURSOR",
                       cursor->getCursorId() );
 
@@ -375,38 +371,38 @@ namespace QueryTests {
         const char* ns;
         PositiveLimit() : ns("unittests.querytests.PositiveLimit") {}
         ~PositiveLimit() {
-            client().dropCollection( ns );
+            _client.dropCollection( ns );
         }
 
         void testLimit(int limit) {
-            ASSERT_EQUALS(client().query( ns, BSONObj(), limit )->itcount(), limit);
+            ASSERT_EQUALS(_client.query( ns, BSONObj(), limit )->itcount(), limit);
         }
         void run() {
             for(int i=0; i<1000; i++)
                 insert( ns, BSON( GENOID << "i" << i ) );
 
-            ASSERT_EQUALS( client().query(ns, BSONObj(),    1 )->itcount(), 1);
-            ASSERT_EQUALS( client().query(ns, BSONObj(),   10 )->itcount(), 10);
-            ASSERT_EQUALS( client().query(ns, BSONObj(),  101 )->itcount(), 101);
-            ASSERT_EQUALS( client().query(ns, BSONObj(),  999 )->itcount(), 999);
-            ASSERT_EQUALS( client().query(ns, BSONObj(), 1000 )->itcount(), 1000);
-            ASSERT_EQUALS( client().query(ns, BSONObj(), 1001 )->itcount(), 1000);
-            ASSERT_EQUALS( client().query(ns, BSONObj(),    0 )->itcount(), 1000);
+            ASSERT_EQUALS( _client.query(ns, BSONObj(),    1 )->itcount(), 1);
+            ASSERT_EQUALS( _client.query(ns, BSONObj(),   10 )->itcount(), 10);
+            ASSERT_EQUALS( _client.query(ns, BSONObj(),  101 )->itcount(), 101);
+            ASSERT_EQUALS( _client.query(ns, BSONObj(),  999 )->itcount(), 999);
+            ASSERT_EQUALS( _client.query(ns, BSONObj(), 1000 )->itcount(), 1000);
+            ASSERT_EQUALS( _client.query(ns, BSONObj(), 1001 )->itcount(), 1000);
+            ASSERT_EQUALS( _client.query(ns, BSONObj(),    0 )->itcount(), 1000);
         }
     };
 
     class ReturnOneOfManyAndTail : public ClientBase {
     public:
         ~ReturnOneOfManyAndTail() {
-            client().dropCollection( "unittests.querytests.ReturnOneOfManyAndTail" );
+            _client.dropCollection( "unittests.querytests.ReturnOneOfManyAndTail" );
         }
         void run() {
             const char *ns = "unittests.querytests.ReturnOneOfManyAndTail";
-            client().createCollection( ns, 1024, true );
+            _client.createCollection( ns, 1024, true );
             insert( ns, BSON( "a" << 0 ) );
             insert( ns, BSON( "a" << 1 ) );
             insert( ns, BSON( "a" << 2 ) );
-            auto_ptr< DBClientCursor > c = client().query( ns, QUERY( "a" << GT << 0 ).hint( BSON( "$natural" << 1 ) ), 1, 0, 0, QueryOption_CursorTailable );
+            auto_ptr< DBClientCursor > c = _client.query( ns, QUERY( "a" << GT << 0 ).hint( BSON( "$natural" << 1 ) ), 1, 0, 0, QueryOption_CursorTailable );
             // If only one result requested, a cursor is not saved.
             ASSERT_EQUALS( 0, c->getCursorId() );
             ASSERT( c->more() );
@@ -417,15 +413,15 @@ namespace QueryTests {
     class TailNotAtEnd : public ClientBase {
     public:
         ~TailNotAtEnd() {
-            client().dropCollection( "unittests.querytests.TailNotAtEnd" );
+            _client.dropCollection( "unittests.querytests.TailNotAtEnd" );
         }
         void run() {
             const char *ns = "unittests.querytests.TailNotAtEnd";
-            client().createCollection( ns, 2047, true );
+            _client.createCollection( ns, 2047, true );
             insert( ns, BSON( "a" << 0 ) );
             insert( ns, BSON( "a" << 1 ) );
             insert( ns, BSON( "a" << 2 ) );
-            auto_ptr< DBClientCursor > c = client().query( ns, Query().hint( BSON( "$natural" << 1 ) ), 2, 0, 0, QueryOption_CursorTailable );
+            auto_ptr< DBClientCursor > c = _client.query( ns, Query().hint( BSON( "$natural" << 1 ) ), 2, 0, 0, QueryOption_CursorTailable );
             ASSERT( 0 != c->getCursorId() );
             while( c->more() )
                 c->next();
@@ -442,16 +438,16 @@ namespace QueryTests {
     class EmptyTail : public ClientBase {
     public:
         ~EmptyTail() {
-            client().dropCollection( "unittests.querytests.EmptyTail" );
+            _client.dropCollection( "unittests.querytests.EmptyTail" );
         }
         void run() {
             const char *ns = "unittests.querytests.EmptyTail";
-            client().createCollection( ns, 1900, true );
-            auto_ptr< DBClientCursor > c = client().query( ns, Query().hint( BSON( "$natural" << 1 ) ), 2, 0, 0, QueryOption_CursorTailable );
+            _client.createCollection( ns, 1900, true );
+            auto_ptr< DBClientCursor > c = _client.query( ns, Query().hint( BSON( "$natural" << 1 ) ), 2, 0, 0, QueryOption_CursorTailable );
             ASSERT_EQUALS( 0, c->getCursorId() );
             ASSERT( c->isDead() );
             insert( ns, BSON( "a" << 0 ) );
-            c = client().query( ns, QUERY( "a" << 1 ).hint( BSON( "$natural" << 1 ) ), 2, 0, 0, QueryOption_CursorTailable );
+            c = _client.query( ns, QUERY( "a" << 1 ).hint( BSON( "$natural" << 1 ) ), 2, 0, 0, QueryOption_CursorTailable );
             ASSERT( 0 != c->getCursorId() );
             ASSERT( !c->isDead() );
         }
@@ -460,14 +456,14 @@ namespace QueryTests {
     class TailableDelete : public ClientBase {
     public:
         ~TailableDelete() {
-            client().dropCollection( "unittests.querytests.TailableDelete" );
+            _client.dropCollection( "unittests.querytests.TailableDelete" );
         }
         void run() {
             const char *ns = "unittests.querytests.TailableDelete";
-            client().createCollection( ns, 8192, true, 2 );
+            _client.createCollection( ns, 8192, true, 2 );
             insert( ns, BSON( "a" << 0 ) );
             insert( ns, BSON( "a" << 1 ) );
-            auto_ptr< DBClientCursor > c = client().query( ns, Query().hint( BSON( "$natural" << 1 ) ), 2, 0, 0, QueryOption_CursorTailable );
+            auto_ptr< DBClientCursor > c = _client.query( ns, Query().hint( BSON( "$natural" << 1 ) ), 2, 0, 0, QueryOption_CursorTailable );
             c->next();
             c->next();
             ASSERT( !c->more() );
@@ -492,19 +488,19 @@ namespace QueryTests {
     class TailableInsertDelete : public ClientBase {
     public:
         ~TailableInsertDelete() {
-            client().dropCollection( "unittests.querytests.TailableInsertDelete" );
+            _client.dropCollection( "unittests.querytests.TailableInsertDelete" );
         }
         void run() {
             const char *ns = "unittests.querytests.TailableInsertDelete";
-            client().createCollection( ns, 1330, true );
+            _client.createCollection( ns, 1330, true );
             insert( ns, BSON( "a" << 0 ) );
             insert( ns, BSON( "a" << 1 ) );
-            auto_ptr< DBClientCursor > c = client().query( ns, Query().hint( BSON( "$natural" << 1 ) ), 2, 0, 0, QueryOption_CursorTailable );
+            auto_ptr< DBClientCursor > c = _client.query( ns, Query().hint( BSON( "$natural" << 1 ) ), 2, 0, 0, QueryOption_CursorTailable );
             c->next();
             c->next();
             ASSERT( !c->more() );
             insert( ns, BSON( "a" << 2 ) );
-            client().remove( ns, QUERY( "a" << 1 ) );
+            _client.remove( ns, QUERY( "a" << 1 ) );
             ASSERT( c->more() );
             ASSERT_EQUALS( 2, c->next().getIntField( "a" ) );
             ASSERT( !c->more() );
@@ -514,21 +510,21 @@ namespace QueryTests {
     class TailCappedOnly : public ClientBase {
     public:
         ~TailCappedOnly() {
-            client().dropCollection( "unittest.querytests.TailCappedOnly" );
+            _client.dropCollection( "unittest.querytests.TailCappedOnly" );
         }
         void run() {
             const char *ns = "unittests.querytests.TailCappedOnly";
-            client().insert( ns, BSONObj() );
-            auto_ptr< DBClientCursor > c = client().query( ns, BSONObj(), 0, 0, 0, QueryOption_CursorTailable );
+            _client.insert( ns, BSONObj() );
+            auto_ptr< DBClientCursor > c = _client.query( ns, BSONObj(), 0, 0, 0, QueryOption_CursorTailable );
             ASSERT( c->isDead() );
-            ASSERT( !client().getLastError().empty() );
+            ASSERT( !_client.getLastError().empty() );
         }
     };
 
     class TailableQueryOnId : public ClientBase {
     public:
         ~TailableQueryOnId() {
-            client().dropCollection( "unittests.querytests.TailableQueryOnId" );
+            _client.dropCollection( "unittests.querytests.TailableQueryOnId" );
         }
 
 		void insertA(const char* ns, int a) {
@@ -542,13 +538,13 @@ namespace QueryTests {
         void run() {
             const char *ns = "unittests.querytests.TailableQueryOnId";
             BSONObj info;
-            client().runCommand( "unittests", BSON( "create" << "querytests.TailableQueryOnId" << "capped" << true << "size" << 8192 << "autoIndexId" << true ), info );
+            _client.runCommand( "unittests", BSON( "create" << "querytests.TailableQueryOnId" << "capped" << true << "size" << 8192 << "autoIndexId" << true ), info );
             insertA( ns, 0 );
             insertA( ns, 1 );
-            auto_ptr< DBClientCursor > c1 = client().query( ns, QUERY( "a" << GT << -1 ), 0, 0, 0, QueryOption_CursorTailable );
+            auto_ptr< DBClientCursor > c1 = _client.query( ns, QUERY( "a" << GT << -1 ), 0, 0, 0, QueryOption_CursorTailable );
             OID id;
             id.init("000000000000000000000000");
-            auto_ptr< DBClientCursor > c2 = client().query( ns, QUERY( "value" << GT << id ), 0, 0, 0, QueryOption_CursorTailable );
+            auto_ptr< DBClientCursor > c2 = _client.query( ns, QUERY( "value" << GT << id ), 0, 0, 0, QueryOption_CursorTailable );
             c1->next();
             c1->next();
             ASSERT( !c1->more() );
@@ -569,20 +565,20 @@ namespace QueryTests {
     class OplogReplayMode : public ClientBase {
     public:
         ~OplogReplayMode() {
-            client().dropCollection( "unittests.querytests.OplogReplayMode" );
+            _client.dropCollection( "unittests.querytests.OplogReplayMode" );
         }
         void run() {
             const char *ns = "unittests.querytests.OplogReplayMode";
             insert( ns, BSON( "ts" << 0 ) );
             insert( ns, BSON( "ts" << 1 ) );
             insert( ns, BSON( "ts" << 2 ) );
-            auto_ptr< DBClientCursor > c = client().query( ns, QUERY( "ts" << GT << 1 ).hint( BSON( "$natural" << 1 ) ), 0, 0, 0, QueryOption_OplogReplay );
+            auto_ptr< DBClientCursor > c = _client.query( ns, QUERY( "ts" << GT << 1 ).hint( BSON( "$natural" << 1 ) ), 0, 0, 0, QueryOption_OplogReplay );
             ASSERT( c->more() );
             ASSERT_EQUALS( 2, c->next().getIntField( "ts" ) );
             ASSERT( !c->more() );
 
             insert( ns, BSON( "ts" << 3 ) );
-            c = client().query( ns, QUERY( "ts" << GT << 1 ).hint( BSON( "$natural" << 1 ) ), 0, 0, 0, QueryOption_OplogReplay );
+            c = _client.query( ns, QUERY( "ts" << GT << 1 ).hint( BSON( "$natural" << 1 ) ), 0, 0, 0, QueryOption_OplogReplay );
             ASSERT( c->more() );
             ASSERT_EQUALS( 2, c->next().getIntField( "ts" ) );
             ASSERT( c->more() );
@@ -592,15 +588,15 @@ namespace QueryTests {
     class OplogReplaySlaveReadTill : public ClientBase {
     public:
         ~OplogReplaySlaveReadTill() {
-            client().dropCollection( "unittests.querytests.OplogReplaySlaveReadTill" );
+            _client.dropCollection( "unittests.querytests.OplogReplaySlaveReadTill" );
         }
         void run() {
             const char *ns = "unittests.querytests.OplogReplaySlaveReadTill";
             Lock::DBWrite lk(_txn.lockState(), ns);
-            Client::Context ctx( ns );
+            Client::Context ctx(&_txn,  ns );
             
             BSONObj info;
-            client().runCommand( "unittests",
+            _client.runCommand( "unittests",
                                 BSON( "create" << "querytests.OplogReplaySlaveReadTill" <<
                                      "capped" << true << "size" << 8192 ),
                                 info );
@@ -612,7 +608,7 @@ namespace QueryTests {
             insert( ns, BSON( "ts" << two ) );
             insert( ns, BSON( "ts" << three ) );
             auto_ptr<DBClientCursor> c =
-            client().query( ns, QUERY( "ts" << GTE << two ).hint( BSON( "$natural" << 1 ) ),
+            _client.query( ns, QUERY( "ts" << GTE << two ).hint( BSON( "$natural" << 1 ) ),
                            0, 0, 0, QueryOption_OplogReplay | QueryOption_CursorTailable );
             ASSERT( c->more() );
             ASSERT_EQUALS( two, c->next()["ts"].Date() );
@@ -626,14 +622,14 @@ namespace QueryTests {
     class OplogReplayExplain : public ClientBase {
     public:
         ~OplogReplayExplain() {
-            client().dropCollection( "unittests.querytests.OplogReplayExplain" );
+            _client.dropCollection( "unittests.querytests.OplogReplayExplain" );
         }
         void run() {
             const char *ns = "unittests.querytests.OplogReplayExplain";
             insert( ns, BSON( "ts" << 0 ) );
             insert( ns, BSON( "ts" << 1 ) );
             insert( ns, BSON( "ts" << 2 ) );
-            auto_ptr< DBClientCursor > c = client().query(
+            auto_ptr< DBClientCursor > c = _client.query(
                 ns, QUERY( "ts" << GT << 1 ).hint( BSON( "$natural" << 1 ) ).explain(),
                 0, 0, 0, QueryOption_OplogReplay );
             ASSERT( c->more() );
@@ -651,11 +647,11 @@ namespace QueryTests {
     class BasicCount : public ClientBase {
     public:
         ~BasicCount() {
-            client().dropCollection( "unittests.querytests.BasicCount" );
+            _client.dropCollection( "unittests.querytests.BasicCount" );
         }
         void run() {
             const char *ns = "unittests.querytests.BasicCount";
-            client().ensureIndex( ns, BSON( "a" << 1 ) );
+            _client.ensureIndex( ns, BSON( "a" << 1 ) );
             count( 0 );
             insert( ns, BSON( "a" << 3 ) );
             count( 0 );
@@ -668,20 +664,20 @@ namespace QueryTests {
         }
     private:
         void count( unsigned long long c ) {
-            ASSERT_EQUALS( c, client().count( "unittests.querytests.BasicCount", BSON( "a" << 4 ) ) );
+            ASSERT_EQUALS( c, _client.count( "unittests.querytests.BasicCount", BSON( "a" << 4 ) ) );
         }
     };
 
     class ArrayId : public ClientBase {
     public:
         ~ArrayId() {
-            client().dropCollection( "unittests.querytests.ArrayId" );
+            _client.dropCollection( "unittests.querytests.ArrayId" );
         }
         void run() {
             const char *ns = "unittests.querytests.ArrayId";
-            client().ensureIndex( ns, BSON( "_id" << 1 ) );
+            _client.ensureIndex( ns, BSON( "_id" << 1 ) );
             ASSERT( !error() );
-            client().insert( ns, fromjson( "{'_id':[1,2]}" ) );
+            _client.insert( ns, fromjson( "{'_id':[1,2]}" ) );
             ASSERT( error() );
         }
     };
@@ -689,14 +685,14 @@ namespace QueryTests {
     class UnderscoreNs : public ClientBase {
     public:
         ~UnderscoreNs() {
-            client().dropCollection( "unittests.querytests._UnderscoreNs" );
+            _client.dropCollection( "unittests.querytests._UnderscoreNs" );
         }
         void run() {
             ASSERT( !error() );
             const char *ns = "unittests.querytests._UnderscoreNs";
-            ASSERT( client().findOne( ns, "{}" ).isEmpty() );
-            client().insert( ns, BSON( "a" << 1 ) );
-            ASSERT_EQUALS( 1, client().findOne( ns, "{}" ).getIntField( "a" ) );
+            ASSERT( _client.findOne( ns, "{}" ).isEmpty() );
+            _client.insert( ns, BSON( "a" << 1 ) );
+            ASSERT_EQUALS( 1, _client.findOne( ns, "{}" ).getIntField( "a" ) );
             ASSERT( !error() );
         }
     };
@@ -704,84 +700,84 @@ namespace QueryTests {
     class EmptyFieldSpec : public ClientBase {
     public:
         ~EmptyFieldSpec() {
-            client().dropCollection( "unittests.querytests.EmptyFieldSpec" );
+            _client.dropCollection( "unittests.querytests.EmptyFieldSpec" );
         }
         void run() {
             const char *ns = "unittests.querytests.EmptyFieldSpec";
-            client().insert( ns, BSON( "a" << 1 ) );
-            ASSERT( !client().findOne( ns, "" ).isEmpty() );
+            _client.insert( ns, BSON( "a" << 1 ) );
+            ASSERT( !_client.findOne( ns, "" ).isEmpty() );
             BSONObj empty;
-            ASSERT( !client().findOne( ns, "", &empty ).isEmpty() );
+            ASSERT( !_client.findOne( ns, "", &empty ).isEmpty() );
         }
     };
 
     class MultiNe : public ClientBase {
     public:
         ~MultiNe() {
-            client().dropCollection( "unittests.querytests.Ne" );
+            _client.dropCollection( "unittests.querytests.Ne" );
         }
         void run() {
             const char *ns = "unittests.querytests.Ne";
-            client().insert( ns, fromjson( "{a:[1,2]}" ) );
-            ASSERT( client().findOne( ns, fromjson( "{a:{$ne:1}}" ) ).isEmpty() );
+            _client.insert( ns, fromjson( "{a:[1,2]}" ) );
+            ASSERT( _client.findOne( ns, fromjson( "{a:{$ne:1}}" ) ).isEmpty() );
             BSONObj spec = fromjson( "{a:{$ne:1,$ne:2}}" );
-            ASSERT( client().findOne( ns, spec ).isEmpty() );
+            ASSERT( _client.findOne( ns, spec ).isEmpty() );
         }
     };
 
     class EmbeddedNe : public ClientBase {
     public:
         ~EmbeddedNe() {
-            client().dropCollection( "unittests.querytests.NestedNe" );
+            _client.dropCollection( "unittests.querytests.NestedNe" );
         }
         void run() {
             const char *ns = "unittests.querytests.NestedNe";
-            client().insert( ns, fromjson( "{a:[{b:1},{b:2}]}" ) );
-            ASSERT( client().findOne( ns, fromjson( "{'a.b':{$ne:1}}" ) ).isEmpty() );
+            _client.insert( ns, fromjson( "{a:[{b:1},{b:2}]}" ) );
+            ASSERT( _client.findOne( ns, fromjson( "{'a.b':{$ne:1}}" ) ).isEmpty() );
         }
     };
 
     class EmbeddedNumericTypes : public ClientBase {
     public:
         ~EmbeddedNumericTypes() {
-            client().dropCollection( "unittests.querytests.NumericEmbedded" );
+            _client.dropCollection( "unittests.querytests.NumericEmbedded" );
         }
         void run() {
             const char *ns = "unittests.querytests.NumericEmbedded";
-            client().insert( ns, BSON( "a" << BSON ( "b" << 1 ) ) );
-            ASSERT( ! client().findOne( ns, BSON( "a" << BSON ( "b" << 1.0 ) ) ).isEmpty() );
-            client().ensureIndex( ns , BSON( "a" << 1 ) );
-            ASSERT( ! client().findOne( ns, BSON( "a" << BSON ( "b" << 1.0 ) ) ).isEmpty() );
+            _client.insert( ns, BSON( "a" << BSON ( "b" << 1 ) ) );
+            ASSERT( ! _client.findOne( ns, BSON( "a" << BSON ( "b" << 1.0 ) ) ).isEmpty() );
+            _client.ensureIndex( ns , BSON( "a" << 1 ) );
+            ASSERT( ! _client.findOne( ns, BSON( "a" << BSON ( "b" << 1.0 ) ) ).isEmpty() );
         }
     };
 
     class AutoResetIndexCache : public ClientBase {
     public:
         ~AutoResetIndexCache() {
-            client().dropCollection( "unittests.querytests.AutoResetIndexCache" );
+            _client.dropCollection( "unittests.querytests.AutoResetIndexCache" );
         }
         static const char *ns() { return "unittests.querytests.AutoResetIndexCache"; }
         static const char *idxNs() { return "unittests.system.indexes"; }
-        void index() { ASSERT( !client().findOne( idxNs(), BSON( "name" << NE << "_id_" ) ).isEmpty() ); }
+        void index() { ASSERT( !_client.findOne( idxNs(), BSON( "name" << NE << "_id_" ) ).isEmpty() ); }
         void noIndex() {
-            BSONObj o = client().findOne( idxNs(), BSON( "name" << NE << "_id_" ) );
+            BSONObj o = _client.findOne( idxNs(), BSON( "name" << NE << "_id_" ) );
             if( !o.isEmpty() ) {
                 cout << o.toString() << endl;
                 ASSERT( false );
             }
         }
         void checkIndex() {
-            client().ensureIndex( ns(), BSON( "a" << 1 ) );
+            _client.ensureIndex( ns(), BSON( "a" << 1 ) );
             index();
         }
         void run() {
-            client().dropDatabase( "unittests" );
+            _client.dropDatabase( "unittests" );
             noIndex();
             checkIndex();
-            client().dropCollection( ns() );
+            _client.dropCollection( ns() );
             noIndex();
             checkIndex();
-            client().dropDatabase( "unittests" );
+            _client.dropDatabase( "unittests" );
             noIndex();
             checkIndex();
         }
@@ -790,130 +786,130 @@ namespace QueryTests {
     class UniqueIndex : public ClientBase {
     public:
         ~UniqueIndex() {
-            client().dropCollection( "unittests.querytests.UniqueIndex" );
+            _client.dropCollection( "unittests.querytests.UniqueIndex" );
         }
         void run() {
             const char *ns = "unittests.querytests.UniqueIndex";
-            client().ensureIndex( ns, BSON( "a" << 1 ), true );
-            client().insert( ns, BSON( "a" << 4 << "b" << 2 ) );
-            client().insert( ns, BSON( "a" << 4 << "b" << 3 ) );
-            ASSERT_EQUALS( 1U, client().count( ns, BSONObj() ) );
-            client().dropCollection( ns );
-            client().ensureIndex( ns, BSON( "b" << 1 ), true );
-            client().insert( ns, BSON( "a" << 4 << "b" << 2 ) );
-            client().insert( ns, BSON( "a" << 4 << "b" << 3 ) );
-            ASSERT_EQUALS( 2U, client().count( ns, BSONObj() ) );
+            _client.ensureIndex( ns, BSON( "a" << 1 ), true );
+            _client.insert( ns, BSON( "a" << 4 << "b" << 2 ) );
+            _client.insert( ns, BSON( "a" << 4 << "b" << 3 ) );
+            ASSERT_EQUALS( 1U, _client.count( ns, BSONObj() ) );
+            _client.dropCollection( ns );
+            _client.ensureIndex( ns, BSON( "b" << 1 ), true );
+            _client.insert( ns, BSON( "a" << 4 << "b" << 2 ) );
+            _client.insert( ns, BSON( "a" << 4 << "b" << 3 ) );
+            ASSERT_EQUALS( 2U, _client.count( ns, BSONObj() ) );
         }
     };
 
     class UniqueIndexPreexistingData : public ClientBase {
     public:
         ~UniqueIndexPreexistingData() {
-            client().dropCollection( "unittests.querytests.UniqueIndexPreexistingData" );
+            _client.dropCollection( "unittests.querytests.UniqueIndexPreexistingData" );
         }
         void run() {
             const char *ns = "unittests.querytests.UniqueIndexPreexistingData";
-            client().insert( ns, BSON( "a" << 4 << "b" << 2 ) );
-            client().insert( ns, BSON( "a" << 4 << "b" << 3 ) );
-            client().ensureIndex( ns, BSON( "a" << 1 ), true );
-            ASSERT_EQUALS( 0U, client().count( "unittests.system.indexes", BSON( "ns" << ns << "name" << NE << "_id_" ) ) );
+            _client.insert( ns, BSON( "a" << 4 << "b" << 2 ) );
+            _client.insert( ns, BSON( "a" << 4 << "b" << 3 ) );
+            _client.ensureIndex( ns, BSON( "a" << 1 ), true );
+            ASSERT_EQUALS( 0U, _client.count( "unittests.system.indexes", BSON( "ns" << ns << "name" << NE << "_id_" ) ) );
         }
     };
 
     class SubobjectInArray : public ClientBase {
     public:
         ~SubobjectInArray() {
-            client().dropCollection( "unittests.querytests.SubobjectInArray" );
+            _client.dropCollection( "unittests.querytests.SubobjectInArray" );
         }
         void run() {
             const char *ns = "unittests.querytests.SubobjectInArray";
-            client().insert( ns, fromjson( "{a:[{b:{c:1}}]}" ) );
-            ASSERT( !client().findOne( ns, BSON( "a.b.c" << 1 ) ).isEmpty() );
-            ASSERT( !client().findOne( ns, fromjson( "{'a.c':null}" ) ).isEmpty() );
+            _client.insert( ns, fromjson( "{a:[{b:{c:1}}]}" ) );
+            ASSERT( !_client.findOne( ns, BSON( "a.b.c" << 1 ) ).isEmpty() );
+            ASSERT( !_client.findOne( ns, fromjson( "{'a.c':null}" ) ).isEmpty() );
         }
     };
 
     class Size : public ClientBase {
     public:
         ~Size() {
-            client().dropCollection( "unittests.querytests.Size" );
+            _client.dropCollection( "unittests.querytests.Size" );
         }
         void run() {
             const char *ns = "unittests.querytests.Size";
-            client().insert( ns, fromjson( "{a:[1,2,3]}" ) );
-            client().ensureIndex( ns, BSON( "a" << 1 ) );
-            ASSERT( client().query( ns, QUERY( "a" << mongo::BSIZE << 3 ).hint( BSON( "a" << 1 ) ) )->more() );
+            _client.insert( ns, fromjson( "{a:[1,2,3]}" ) );
+            _client.ensureIndex( ns, BSON( "a" << 1 ) );
+            ASSERT( _client.query( ns, QUERY( "a" << mongo::BSIZE << 3 ).hint( BSON( "a" << 1 ) ) )->more() );
         }
     };
 
     class FullArray : public ClientBase {
     public:
         ~FullArray() {
-            client().dropCollection( "unittests.querytests.IndexedArray" );
+            _client.dropCollection( "unittests.querytests.IndexedArray" );
         }
         void run() {
             const char *ns = "unittests.querytests.IndexedArray";
-            client().insert( ns, fromjson( "{a:[1,2,3]}" ) );
-            ASSERT( client().query( ns, Query( "{a:[1,2,3]}" ) )->more() );
-            client().ensureIndex( ns, BSON( "a" << 1 ) );
-            ASSERT( client().query( ns, Query( "{a:{$in:[1,[1,2,3]]}}" ).hint( BSON( "a" << 1 ) ) )->more() );
-            ASSERT( client().query( ns, Query( "{a:[1,2,3]}" ).hint( BSON( "a" << 1 ) ) )->more() ); // SERVER-146
+            _client.insert( ns, fromjson( "{a:[1,2,3]}" ) );
+            ASSERT( _client.query( ns, Query( "{a:[1,2,3]}" ) )->more() );
+            _client.ensureIndex( ns, BSON( "a" << 1 ) );
+            ASSERT( _client.query( ns, Query( "{a:{$in:[1,[1,2,3]]}}" ).hint( BSON( "a" << 1 ) ) )->more() );
+            ASSERT( _client.query( ns, Query( "{a:[1,2,3]}" ).hint( BSON( "a" << 1 ) ) )->more() ); // SERVER-146
         }
     };
 
     class InsideArray : public ClientBase {
     public:
         ~InsideArray() {
-            client().dropCollection( "unittests.querytests.InsideArray" );
+            _client.dropCollection( "unittests.querytests.InsideArray" );
         }
         void run() {
             const char *ns = "unittests.querytests.InsideArray";
-            client().insert( ns, fromjson( "{a:[[1],2]}" ) );
+            _client.insert( ns, fromjson( "{a:[[1],2]}" ) );
             check( "$natural" );
-            client().ensureIndex( ns, BSON( "a" << 1 ) );
+            _client.ensureIndex( ns, BSON( "a" << 1 ) );
             check( "a" ); // SERVER-146
         }
     private:
         void check( const string &hintField ) {
             const char *ns = "unittests.querytests.InsideArray";
-            ASSERT( client().query( ns, Query( "{a:[[1],2]}" ).hint( BSON( hintField << 1 ) ) )->more() );
-            ASSERT( client().query( ns, Query( "{a:[1]}" ).hint( BSON( hintField << 1 ) ) )->more() );
-            ASSERT( client().query( ns, Query( "{a:2}" ).hint( BSON( hintField << 1 ) ) )->more() );
-            ASSERT( !client().query( ns, Query( "{a:1}" ).hint( BSON( hintField << 1 ) ) )->more() );
+            ASSERT( _client.query( ns, Query( "{a:[[1],2]}" ).hint( BSON( hintField << 1 ) ) )->more() );
+            ASSERT( _client.query( ns, Query( "{a:[1]}" ).hint( BSON( hintField << 1 ) ) )->more() );
+            ASSERT( _client.query( ns, Query( "{a:2}" ).hint( BSON( hintField << 1 ) ) )->more() );
+            ASSERT( !_client.query( ns, Query( "{a:1}" ).hint( BSON( hintField << 1 ) ) )->more() );
         }
     };
 
     class IndexInsideArrayCorrect : public ClientBase {
     public:
         ~IndexInsideArrayCorrect() {
-            client().dropCollection( "unittests.querytests.IndexInsideArrayCorrect" );
+            _client.dropCollection( "unittests.querytests.IndexInsideArrayCorrect" );
         }
         void run() {
             const char *ns = "unittests.querytests.IndexInsideArrayCorrect";
-            client().insert( ns, fromjson( "{'_id':1,a:[1]}" ) );
-            client().insert( ns, fromjson( "{'_id':2,a:[[1]]}" ) );
-            client().ensureIndex( ns, BSON( "a" << 1 ) );
-            ASSERT_EQUALS( 1, client().query( ns, Query( "{a:[1]}" ).hint( BSON( "a" << 1 ) ) )->next().getIntField( "_id" ) );
+            _client.insert( ns, fromjson( "{'_id':1,a:[1]}" ) );
+            _client.insert( ns, fromjson( "{'_id':2,a:[[1]]}" ) );
+            _client.ensureIndex( ns, BSON( "a" << 1 ) );
+            ASSERT_EQUALS( 1, _client.query( ns, Query( "{a:[1]}" ).hint( BSON( "a" << 1 ) ) )->next().getIntField( "_id" ) );
         }
     };
 
     class SubobjArr : public ClientBase {
     public:
         ~SubobjArr() {
-            client().dropCollection( "unittests.querytests.SubobjArr" );
+            _client.dropCollection( "unittests.querytests.SubobjArr" );
         }
         void run() {
             const char *ns = "unittests.querytests.SubobjArr";
-            client().insert( ns, fromjson( "{a:[{b:[1]}]}" ) );
+            _client.insert( ns, fromjson( "{a:[{b:[1]}]}" ) );
             check( "$natural" );
-            client().ensureIndex( ns, BSON( "a" << 1 ) );
+            _client.ensureIndex( ns, BSON( "a" << 1 ) );
             check( "a" );
         }
     private:
         void check( const string &hintField ) {
             const char *ns = "unittests.querytests.SubobjArr";
-            ASSERT( client().query( ns, Query( "{'a.b':1}" ).hint( BSON( hintField << 1 ) ) )->more() );
-            ASSERT( client().query( ns, Query( "{'a.b':[1]}" ).hint( BSON( hintField << 1 ) ) )->more() );
+            ASSERT( _client.query( ns, Query( "{'a.b':1}" ).hint( BSON( hintField << 1 ) ) )->more() );
+            ASSERT( _client.query( ns, Query( "{'a.b':[1]}" ).hint( BSON( hintField << 1 ) ) )->more() );
         }
     };
 
@@ -921,16 +917,16 @@ namespace QueryTests {
     public:
         MinMax() : ns( "unittests.querytests.MinMax" ) {}
         ~MinMax() {
-            client().dropCollection( "unittests.querytests.MinMax" );
+            _client.dropCollection( "unittests.querytests.MinMax" );
         }
         void run() {
-            client().ensureIndex( ns, BSON( "a" << 1 << "b" << 1 ) );
-            client().insert( ns, BSON( "a" << 1 << "b" << 1 ) );
-            client().insert( ns, BSON( "a" << 1 << "b" << 2 ) );
-            client().insert( ns, BSON( "a" << 2 << "b" << 1 ) );
-            client().insert( ns, BSON( "a" << 2 << "b" << 2 ) );
+            _client.ensureIndex( ns, BSON( "a" << 1 << "b" << 1 ) );
+            _client.insert( ns, BSON( "a" << 1 << "b" << 1 ) );
+            _client.insert( ns, BSON( "a" << 1 << "b" << 2 ) );
+            _client.insert( ns, BSON( "a" << 2 << "b" << 1 ) );
+            _client.insert( ns, BSON( "a" << 2 << "b" << 2 ) );
 
-            ASSERT_EQUALS( 4, count( client().query( ns, BSONObj() ) ) );
+            ASSERT_EQUALS( 4, count( _client.query( ns, BSONObj() ) ) );
             BSONObj hints[] = { BSONObj(), BSON( "a" << 1 << "b" << 1 ) };
             for( int i = 0; i < 2; ++i ) {
                 check( 0, 0, 3, 3, 4, hints[ i ] );
@@ -954,7 +950,7 @@ namespace QueryTests {
             q = q.minKey( BSON( "a" << minA << "b" << minB ) ).maxKey( BSON( "a" << maxA << "b" << maxB ) );
             if ( !hint.isEmpty() )
                 q.hint( hint );
-            return client().query( ns, q );
+            return _client.query( ns, q );
         }
         void check( int minA, int minB, int maxA, int maxB, int expectedCount, const BSONObj &hint = empty_ ) {
             ASSERT_EQUALS( expectedCount, count( query( minA, minB, maxA, maxB, hint ) ) );
@@ -976,15 +972,15 @@ namespace QueryTests {
     public:
         MatchCodeCodeWScope() : _ns( "unittests.querytests.MatchCodeCodeWScope" ) {}
         ~MatchCodeCodeWScope() {
-            client().dropCollection( "unittests.querytests.MatchCodeCodeWScope" );
+            _client.dropCollection( "unittests.querytests.MatchCodeCodeWScope" );
         }
         void run() {
             checkMatch();
-            client().ensureIndex( _ns, BSON( "a" << 1 ) );
+            _client.ensureIndex( _ns, BSON( "a" << 1 ) );
             checkMatch();
             // Use explain queries to check index bounds.
             {
-                BSONObj explain = client().findOne( _ns, QUERY( "a" << BSON( "$type" << (int)Code ) ).explain() );
+                BSONObj explain = _client.findOne( _ns, QUERY( "a" << BSON( "$type" << (int)Code ) ).explain() );
                 BSONObjBuilder lower;
                 lower.appendCode( "", "" );
                 BSONObjBuilder upper;
@@ -993,7 +989,7 @@ namespace QueryTests {
                 ASSERT( upper.done().firstElement().valuesEqual( explain[ "indexBounds" ].Obj()[ "a" ].Array()[ 0 ].Array()[ 1 ] ) );
             }
             {
-                BSONObj explain = client().findOne( _ns, QUERY( "a" << BSON( "$type" << (int)CodeWScope ) ).explain() );
+                BSONObj explain = _client.findOne( _ns, QUERY( "a" << BSON( "$type" << (int)CodeWScope ) ).explain() );
                 BSONObjBuilder lower;
                 lower.appendCodeWScope( "", "", BSONObj() );
                 // This upper bound may change if a new bson type is added.
@@ -1005,16 +1001,16 @@ namespace QueryTests {
         }
     private:
         void checkMatch() {
-            client().remove( _ns, BSONObj() );
+            _client.remove( _ns, BSONObj() );
             
-            client().insert( _ns, code() );
-            client().insert( _ns, codeWScope() );
+            _client.insert( _ns, code() );
+            _client.insert( _ns, codeWScope() );
             
-            ASSERT_EQUALS( 1U, client().count( _ns, code() ) );
-            ASSERT_EQUALS( 1U, client().count( _ns, codeWScope() ) );
+            ASSERT_EQUALS( 1U, _client.count( _ns, code() ) );
+            ASSERT_EQUALS( 1U, _client.count( _ns, codeWScope() ) );
             
-            ASSERT_EQUALS( 1U, client().count( _ns, BSON( "a" << BSON( "$type" << (int)Code ) ) ) );
-            ASSERT_EQUALS( 1U, client().count( _ns, BSON( "a" << BSON( "$type" << (int)CodeWScope ) ) ) );
+            ASSERT_EQUALS( 1U, _client.count( _ns, BSON( "a" << BSON( "$type" << (int)Code ) ) ) );
+            ASSERT_EQUALS( 1U, _client.count( _ns, BSON( "a" << BSON( "$type" << (int)CodeWScope ) ) ) );
         }
         BSONObj code() const {
             BSONObjBuilder codeBuilder;
@@ -1033,19 +1029,19 @@ namespace QueryTests {
     public:
         MatchDBRefType() : _ns( "unittests.querytests.MatchDBRefType" ) {}
         ~MatchDBRefType() {
-            client().dropCollection( "unittests.querytests.MatchDBRefType" );
+            _client.dropCollection( "unittests.querytests.MatchDBRefType" );
         }
         void run() {
             checkMatch();
-            client().ensureIndex( _ns, BSON( "a" << 1 ) );
+            _client.ensureIndex( _ns, BSON( "a" << 1 ) );
             checkMatch();
         }
     private:
         void checkMatch() {
-            client().remove( _ns, BSONObj() );            
-            client().insert( _ns, dbref() );
-            ASSERT_EQUALS( 1U, client().count( _ns, dbref() ) );
-            ASSERT_EQUALS( 1U, client().count( _ns, BSON( "a" << BSON( "$type" << (int)DBRef ) ) ) );
+            _client.remove( _ns, BSONObj() );            
+            _client.insert( _ns, dbref() );
+            ASSERT_EQUALS( 1U, _client.count( _ns, dbref() ) );
+            ASSERT_EQUALS( 1U, _client.count( _ns, BSON( "a" << BSON( "$type" << (int)DBRef ) ) ) );
         }
         BSONObj dbref() const {
             BSONObjBuilder b;
@@ -1060,8 +1056,8 @@ namespace QueryTests {
     public:
         void run() {
             Lock::GlobalWrite lk(_txn.lockState());
-            Client::Context ctx( "unittests.DirectLocking" );
-            client().remove( "a.b", BSONObj() );
+            Client::Context ctx(&_txn, "unittests.DirectLocking");
+            _client.remove( "a.b", BSONObj() );
             ASSERT_EQUALS( "unittests", ctx.db()->name() );
         }
         const char *ns;
@@ -1070,39 +1066,39 @@ namespace QueryTests {
     class FastCountIn : public ClientBase {
     public:
         ~FastCountIn() {
-            client().dropCollection( "unittests.querytests.FastCountIn" );
+            _client.dropCollection( "unittests.querytests.FastCountIn" );
         }
         void run() {
             const char *ns = "unittests.querytests.FastCountIn";
-            client().insert( ns, BSON( "i" << "a" ) );
-            client().ensureIndex( ns, BSON( "i" << 1 ) );
-            ASSERT_EQUALS( 1U, client().count( ns, fromjson( "{i:{$in:['a']}}" ) ) );
+            _client.insert( ns, BSON( "i" << "a" ) );
+            _client.ensureIndex( ns, BSON( "i" << 1 ) );
+            ASSERT_EQUALS( 1U, _client.count( ns, fromjson( "{i:{$in:['a']}}" ) ) );
         }
     };
 
     class EmbeddedArray : public ClientBase {
     public:
         ~EmbeddedArray() {
-            client().dropCollection( "unittests.querytests.EmbeddedArray" );
+            _client.dropCollection( "unittests.querytests.EmbeddedArray" );
         }
         void run() {
             const char *ns = "unittests.querytests.EmbeddedArray";
-            client().insert( ns, fromjson( "{foo:{bar:['spam']}}" ) );
-            client().insert( ns, fromjson( "{foo:{bar:['spam','eggs']}}" ) );
-            client().insert( ns, fromjson( "{bar:['spam']}" ) );
-            client().insert( ns, fromjson( "{bar:['spam','eggs']}" ) );
-            ASSERT_EQUALS( 2U, client().count( ns, BSON( "bar" << "spam" ) ) );
-            ASSERT_EQUALS( 2U, client().count( ns, BSON( "foo.bar" << "spam" ) ) );
+            _client.insert( ns, fromjson( "{foo:{bar:['spam']}}" ) );
+            _client.insert( ns, fromjson( "{foo:{bar:['spam','eggs']}}" ) );
+            _client.insert( ns, fromjson( "{bar:['spam']}" ) );
+            _client.insert( ns, fromjson( "{bar:['spam','eggs']}" ) );
+            ASSERT_EQUALS( 2U, _client.count( ns, BSON( "bar" << "spam" ) ) );
+            ASSERT_EQUALS( 2U, _client.count( ns, BSON( "foo.bar" << "spam" ) ) );
         }
     };
 
     class DifferentNumbers : public ClientBase {
     public:
         ~DifferentNumbers() {
-            client().dropCollection( "unittests.querytests.DifferentNumbers" );
+            _client.dropCollection( "unittests.querytests.DifferentNumbers" );
         }
         void t( const char * ns ) {
-            auto_ptr< DBClientCursor > cursor = client().query( ns, Query().sort( "7" ) );
+            auto_ptr< DBClientCursor > cursor = _client.query( ns, Query().sort( "7" ) );
             while ( cursor->more() ) {
                 BSONObj o = cursor->next();
                 verify( o.valid() );
@@ -1112,15 +1108,15 @@ namespace QueryTests {
         }
         void run() {
             const char *ns = "unittests.querytests.DifferentNumbers";
-            { BSONObjBuilder b; b.append( "7" , (int)4 ); client().insert( ns , b.obj() ); }
-            { BSONObjBuilder b; b.append( "7" , (long long)2 ); client().insert( ns , b.obj() ); }
-            { BSONObjBuilder b; b.appendNull( "7" ); client().insert( ns , b.obj() ); }
-            { BSONObjBuilder b; b.append( "7" , "b" ); client().insert( ns , b.obj() ); }
-            { BSONObjBuilder b; b.appendNull( "8" ); client().insert( ns , b.obj() ); }
-            { BSONObjBuilder b; b.append( "7" , (double)3.7 ); client().insert( ns , b.obj() ); }
+            { BSONObjBuilder b; b.append( "7" , (int)4 ); _client.insert( ns , b.obj() ); }
+            { BSONObjBuilder b; b.append( "7" , (long long)2 ); _client.insert( ns , b.obj() ); }
+            { BSONObjBuilder b; b.appendNull( "7" ); _client.insert( ns , b.obj() ); }
+            { BSONObjBuilder b; b.append( "7" , "b" ); _client.insert( ns , b.obj() ); }
+            { BSONObjBuilder b; b.appendNull( "8" ); _client.insert( ns , b.obj() ); }
+            { BSONObjBuilder b; b.append( "7" , (double)3.7 ); _client.insert( ns , b.obj() ); }
 
             t(ns);
-            client().ensureIndex( ns , BSON( "7" << 1 ) );
+            _client.ensureIndex( ns , BSON( "7" << 1 ) );
             t(ns);
         }
     };
@@ -1131,15 +1127,15 @@ namespace QueryTests {
         CollectionBase( string leaf ) {
             _ns = "unittests.querytests.";
             _ns += leaf;
-            client().dropCollection( ns() );
+            _client.dropCollection( ns() );
         }
 
         virtual ~CollectionBase() {
-            client().dropCollection( ns() );
+            _client.dropCollection( ns() );
         }
 
         int count() {
-            return (int) client().count( ns() );
+            return (int) _client.count( ns() );
         }
 
         size_t numCursorsOpen() {
@@ -1163,16 +1159,16 @@ namespace QueryTests {
         SymbolStringSame() : CollectionBase( "symbolstringsame" ) {}
 
         void run() {
-            { BSONObjBuilder b; b.appendSymbol( "x" , "eliot" ); b.append( "z" , 17 ); client().insert( ns() , b.obj() ); }
-            ASSERT_EQUALS( 17 , client().findOne( ns() , BSONObj() )["z"].number() );
+            { BSONObjBuilder b; b.appendSymbol( "x" , "eliot" ); b.append( "z" , 17 ); _client.insert( ns() , b.obj() ); }
+            ASSERT_EQUALS( 17 , _client.findOne( ns() , BSONObj() )["z"].number() );
             {
                 BSONObjBuilder b;
                 b.appendSymbol( "x" , "eliot" );
-                ASSERT_EQUALS( 17 , client().findOne( ns() , b.obj() )["z"].number() );
+                ASSERT_EQUALS( 17 , _client.findOne( ns() , b.obj() )["z"].number() );
             }
-            ASSERT_EQUALS( 17 , client().findOne( ns() , BSON( "x" << "eliot" ) )["z"].number() );
-            client().ensureIndex( ns() , BSON( "x" << 1 ) );
-            ASSERT_EQUALS( 17 , client().findOne( ns() , BSON( "x" << "eliot" ) )["z"].number() );
+            ASSERT_EQUALS( 17 , _client.findOne( ns() , BSON( "x" << "eliot" ) )["z"].number() );
+            _client.ensureIndex( ns() , BSON( "x" << 1 ) );
+            ASSERT_EQUALS( 17 , _client.findOne( ns() , BSON( "x" << "eliot" ) )["z"].number() );
         }
     };
 
@@ -1180,7 +1176,7 @@ namespace QueryTests {
     public:
 
         TailableCappedRaceCondition() : CollectionBase( "tailablecappedrace" ) {
-            client().dropCollection( ns() );
+            _client.dropCollection( ns() );
             _n = 0;
         }
         void run() {
@@ -1197,7 +1193,7 @@ namespace QueryTests {
 
             int a = count();
 
-            auto_ptr< DBClientCursor > c = client().query( ns() , QUERY( "i" << GT << 0 ).hint( BSON( "$natural" << 1 ) ), 0, 0, 0, QueryOption_CursorTailable );
+            auto_ptr< DBClientCursor > c = _client.query( ns() , QUERY( "i" << GT << 0 ).hint( BSON( "$natural" << 1 ) ), 0, 0, 0, QueryOption_CursorTailable );
             int n=0;
             while ( c->more() ) {
                 BSONObj z = c->next();
@@ -1291,7 +1287,7 @@ namespace QueryTests {
                 insert( ns() , BSON( "_id" << i << "x" << i * 2 ) );
             }
             for ( int i=0; i<1000; i+=2 ) {
-                client_.remove( ns() , BSON( "_id" << i ) );
+                _client.remove( ns() , BSON( "_id" << i ) );
             }
 
             BSONObj res;
@@ -1325,18 +1321,18 @@ namespace QueryTests {
 
         void run() {
             BSONObj info;
-            ASSERT( client().runCommand( "unittests", BSON( "create" << "querytests.findingstart" << "capped" << true << "$nExtents" << 5 << "autoIndexId" << false ), info ) );
+            ASSERT( _client.runCommand( "unittests", BSON( "create" << "querytests.findingstart" << "capped" << true << "$nExtents" << 5 << "autoIndexId" << false ), info ) );
 
             int i = 0;
             for( int oldCount = -1;
                     count() != oldCount;
-                    oldCount = count(), client().insert( ns(), BSON( "ts" << i++ ) ) );
+                    oldCount = count(), _client.insert( ns(), BSON( "ts" << i++ ) ) );
 
             for( int k = 0; k < 5; ++k ) {
-                client().insert( ns(), BSON( "ts" << i++ ) );
-                int min = client().query( ns(), Query().sort( BSON( "$natural" << 1 ) ) )->next()[ "ts" ].numberInt();
+                _client.insert( ns(), BSON( "ts" << i++ ) );
+                int min = _client.query( ns(), Query().sort( BSON( "$natural" << 1 ) ) )->next()[ "ts" ].numberInt();
                 for( int j = -1; j < i; ++j ) {
-                    auto_ptr< DBClientCursor > c = client().query( ns(), QUERY( "ts" << GTE << j ), 0, 0, 0, QueryOption_OplogReplay );
+                    auto_ptr< DBClientCursor > c = _client.query( ns(), QUERY( "ts" << GTE << j ), 0, 0, 0, QueryOption_OplogReplay );
                     ASSERT( c->more() );
                     BSONObj next = c->next();
                     ASSERT( !next[ "ts" ].eoo() );
@@ -1356,16 +1352,16 @@ namespace QueryTests {
             size_t startNumCursors = numCursorsOpen();
 
             BSONObj info;
-            ASSERT( client().runCommand( "unittests", BSON( "create" << "querytests.findingstart" << "capped" << true << "$nExtents" << 5 << "autoIndexId" << false ), info ) );
+            ASSERT( _client.runCommand( "unittests", BSON( "create" << "querytests.findingstart" << "capped" << true << "$nExtents" << 5 << "autoIndexId" << false ), info ) );
 
             int i = 0;
-            for( ; i < 150; client().insert( ns(), BSON( "ts" << i++ ) ) );
+            for( ; i < 150; _client.insert( ns(), BSON( "ts" << i++ ) ) );
 
             for( int k = 0; k < 5; ++k ) {
-                client().insert( ns(), BSON( "ts" << i++ ) );
-                int min = client().query( ns(), Query().sort( BSON( "$natural" << 1 ) ) )->next()[ "ts" ].numberInt();
+                _client.insert( ns(), BSON( "ts" << i++ ) );
+                int min = _client.query( ns(), Query().sort( BSON( "$natural" << 1 ) ) )->next()[ "ts" ].numberInt();
                 for( int j = -1; j < i; ++j ) {
-                    auto_ptr< DBClientCursor > c = client().query( ns(), QUERY( "ts" << GTE << j ), 0, 0, 0, QueryOption_OplogReplay );
+                    auto_ptr< DBClientCursor > c = _client.query( ns(), QUERY( "ts" << GTE << j ), 0, 0, 0, QueryOption_OplogReplay );
                     ASSERT( c->more() );
                     BSONObj next = c->next();
                     ASSERT( !next[ "ts" ].eoo() );
@@ -1389,19 +1385,19 @@ namespace QueryTests {
             size_t startNumCursors = numCursorsOpen();
 
             // Check OplogReplay mode with missing collection.
-            auto_ptr< DBClientCursor > c0 = client().query( ns(), QUERY( "ts" << GTE << 50 ), 0, 0, 0, QueryOption_OplogReplay );
+            auto_ptr< DBClientCursor > c0 = _client.query( ns(), QUERY( "ts" << GTE << 50 ), 0, 0, 0, QueryOption_OplogReplay );
             ASSERT( !c0->more() );
 
             BSONObj info;
-            ASSERT( client().runCommand( "unittests", BSON( "create" << "querytests.findingstart" << "capped" << true << "$nExtents" << 5 << "autoIndexId" << false ), info ) );
+            ASSERT( _client.runCommand( "unittests", BSON( "create" << "querytests.findingstart" << "capped" << true << "$nExtents" << 5 << "autoIndexId" << false ), info ) );
             
             // Check OplogReplay mode with empty collection.
-            auto_ptr< DBClientCursor > c = client().query( ns(), QUERY( "ts" << GTE << 50 ), 0, 0, 0, QueryOption_OplogReplay );
+            auto_ptr< DBClientCursor > c = _client.query( ns(), QUERY( "ts" << GTE << 50 ), 0, 0, 0, QueryOption_OplogReplay );
             ASSERT( !c->more() );
 
             // Check with some docs in the collection.
-            for( int i = 100; i < 150; client().insert( ns(), BSON( "ts" << i++ ) ) );
-            c = client().query( ns(), QUERY( "ts" << GTE << 50 ), 0, 0, 0, QueryOption_OplogReplay );
+            for( int i = 100; i < 150; _client.insert( ns(), BSON( "ts" << i++ ) ) );
+            c = _client.query( ns(), QUERY( "ts" << GTE << 50 ), 0, 0, 0, QueryOption_OplogReplay );
             ASSERT( c->more() );
             ASSERT_EQUALS( 100, c->next()[ "ts" ].numberInt() );
 
@@ -1415,7 +1411,7 @@ namespace QueryTests {
         WhatsMyUri() : CollectionBase( "whatsmyuri" ) {}
         void run() {
             BSONObj result;
-            client().runCommand( "admin", BSON( "whatsmyuri" << 1 ), result );
+            _client.runCommand( "admin", BSON( "whatsmyuri" << 1 ), result );
             ASSERT_EQUALS( unknownAddress.toString(), result[ "you" ].str() );
         }
     };
@@ -1425,7 +1421,8 @@ namespace QueryTests {
         CollectionInternalBase( const char *nsLeaf ) :
           CollectionBase( nsLeaf ),
           _lk(_txn.lockState(), ns() ),
-          _ctx( ns() ) {
+          _ctx(&_txn, ns()) {
+
         }
     private:
         Lock::DBWrite _lk;
@@ -1437,10 +1434,10 @@ namespace QueryTests {
         Exhaust() : CollectionInternalBase( "exhaust" ) {}
         void run() {
             BSONObj info;
-            ASSERT( client().runCommand( "unittests",
+            ASSERT( _client.runCommand( "unittests",
                                         BSON( "create" << "querytests.exhaust" <<
                                              "capped" << true << "size" << 8192 ), info ) );
-            client().insert( ns(), BSON( "ts" << 0 ) );
+            _client.insert( ns(), BSON( "ts" << 0 ) );
             Message message;
             assembleRequest( ns(), BSON( "ts" << GTE << 0 ), 0, 0, 0,
                             QueryOption_OplogReplay | QueryOption_CursorTailable |
@@ -1462,7 +1459,7 @@ namespace QueryTests {
             for( int i = 0; i < 150; ++i ) {
                 insert( ns(), BSONObj() );
             }
-            auto_ptr<DBClientCursor> c = client().query( ns(), Query() );
+            auto_ptr<DBClientCursor> c = _client.query( ns(), Query() );
             ASSERT( c->more() );
             long long cursorId = c->getCursorId();
             
@@ -1485,7 +1482,7 @@ namespace QueryTests {
             for( int i = 0; i < 5; ++i ) {
                 insert( ns(), BSONObj() );
             }
-            auto_ptr<DBClientCursor> c = client().query( ns(), Query(), 5 );
+            auto_ptr<DBClientCursor> c = _client.query( ns(), Query(), 5 );
             ASSERT( c->more() );
             // With five results and a batch size of 5, no cursor is created.
             ASSERT_EQUALS( 0, c->getCursorId() );
@@ -1500,8 +1497,8 @@ namespace QueryTests {
         KillPinnedCursor() : CollectionBase( "killpinnedcursor" ) {
         }
         void run() {
-            client().insert( ns(), vector<BSONObj>( 3, BSONObj() ) );
-            auto_ptr<DBClientCursor> cursor = client().query( ns(), BSONObj(), 0, 0, 0, 0, 2 );
+            _client.insert( ns(), vector<BSONObj>( 3, BSONObj() ) );
+            auto_ptr<DBClientCursor> cursor = _client.query( ns(), BSONObj(), 0, 0, 0, 0, 2 );
             ASSERT_EQUALS( 2, cursor->objsLeftInBatch() );
             long long cursorId = cursor->getCursorId();
             
@@ -1513,7 +1510,7 @@ namespace QueryTests {
                               MsgAssertionException);
                 string expectedAssertion =
                         str::stream() << "Cannot kill active cursor " << cursorId;
-                ASSERT_EQUALS( expectedAssertion, client().getLastError() );
+                ASSERT_EQUALS( expectedAssertion, _client.getLastError() );
             }
             
             // Verify that the remaining document is read from the cursor.
diff --git a/src/mongo/dbtests/replsettests.cpp b/src/mongo/dbtests/replsettests.cpp
index 07c57608ea8..0cd3597f34c 100644
--- a/src/mongo/dbtests/replsettests.cpp
+++ b/src/mongo/dbtests/replsettests.cpp
@@ -128,15 +128,16 @@ namespace ReplSetTests {
 
 
     class Base {
-    private:
-        DBDirectClient _client;
-
     protected:
         static BackgroundSyncTest* _bgsync;
         static repl::SyncTail* _tailer;
 
+        OperationContextImpl _txn;
+        DBDirectClient _client;
+
     public:
-        Base() {
+        Base() : _client(&_txn) {
+
         }
 
         ~Base() {
@@ -146,48 +147,22 @@ namespace ReplSetTests {
             return "unittests.repltests";
         }
 
-        DBDirectClient *client() { return &_client; }
-
-        static void insert( const BSONObj &o, bool god = false ) {
-            OperationContextImpl txn;
-            Lock::DBWrite lk(txn.lockState(), ns());
-            Client::Context ctx(ns());
-            
-            Database* db = ctx.db();
-            Collection* coll = db->getCollection(&txn, ns());
-            if (!coll) {
-                coll = db->createCollection(&txn, ns());
-            }
-
-            if (o.hasField("_id")) {
-                coll->insertDocument(&txn, o, true);
-                return;
-            }
-
-            class BSONObjBuilder b;
-            OID id;
-            id.init();
-            b.appendOID("_id", &id);
-            b.appendElements(o);
-            coll->insertDocument(&txn, b.obj(), true);
-        }
-
         BSONObj findOne( const BSONObj &query = BSONObj() ) {
-            return client()->findOne( ns(), query );
+            return _client.findOne( ns(), query );
         }
 
         void drop() {
-            OperationContextImpl txn;
-            Client::WriteContext c(&txn, ns());
+            Client::WriteContext c(&_txn, ns());
 
             Database* db = c.ctx().db();
 
-            if ( db->getCollection( &txn, ns() ) == NULL ) {
+            if ( db->getCollection( &_txn, ns() ) == NULL ) {
                 return;
             }
 
-            db->dropCollection(&txn, ns());
+            db->dropCollection(&_txn, ns());
         }
+
         static void setup() {
             replSettings.replSet = "foo";
             replSettings.oplogSize = 5 * 1024 * 1024;
@@ -206,6 +181,29 @@ namespace ReplSetTests {
             delete repl::theReplSet;
             repl::theReplSet = rst;
         }
+
+        static void insert(OperationContext* txn, const BSONObj &o, bool god = false) {
+            Lock::DBWrite lk(txn->lockState(), ns());
+            Client::Context ctx(txn, ns());
+
+            Database* db = ctx.db();
+            Collection* coll = db->getCollection(txn, ns());
+            if (!coll) {
+                coll = db->createCollection(txn, ns());
+            }
+
+            if (o.hasField("_id")) {
+                coll->insertDocument(txn, o, true);
+                return;
+            }
+
+            class BSONObjBuilder b;
+            OID id;
+            id.init();
+            b.appendOID("_id", &id);
+            b.appendElements(o);
+            coll->insertDocument(txn, b.obj(), true);
+        }
     };
 
     BackgroundSyncTest* Base::_bgsync = NULL;
@@ -274,7 +272,7 @@ namespace ReplSetTests {
                 return true;
             }
 
-            Base::insert(BSON("_id" << 123));
+            Base::insert(txn, BSON("_id" << 123));
             return true;
         }
     };
@@ -309,7 +307,6 @@ namespace ReplSetTests {
     class CappedInitialSync : public Base {
         string _cappedNs;
 
-        OperationContextImpl _txn;
         Lock::DBWrite _lk;
 
         string spec() const {
@@ -317,17 +314,15 @@ namespace ReplSetTests {
         }
 
         void create() {
-            Client::Context c(_cappedNs);
-            OperationContextImpl txn;
-            ASSERT( userCreateNS( &txn, c.db(), _cappedNs, fromjson( spec() ), false ).isOK() );
+            Client::Context c(&_txn, _cappedNs);
+            ASSERT( userCreateNS( &_txn, c.db(), _cappedNs, fromjson( spec() ), false ).isOK() );
         }
 
         void dropCapped() {
-            Client::Context c(_cappedNs);
-            OperationContextImpl txn;
+            Client::Context c(&_txn, _cappedNs);
             Database* db = c.db();
-            if ( db->getCollection( &txn, _cappedNs ) ) {
-                db->dropCollection( &txn, _cappedNs );
+            if ( db->getCollection( &_txn, _cappedNs ) ) {
+                db->dropCollection( &_txn, _cappedNs );
             }
         }
 
@@ -345,6 +340,7 @@ namespace ReplSetTests {
             verify(!apply(o));
             return o;
         }
+
     public:
         CappedInitialSync() : 
                 _cappedNs("unittests.foo.bar"), _lk(_txn.lockState(), _cappedNs) {
@@ -361,20 +357,18 @@ namespace ReplSetTests {
 
         // returns true on success, false on failure
         bool apply(const BSONObj& op) {
-            Client::Context ctx( _cappedNs );
-            OperationContextImpl txn;
+            Client::Context ctx(&_txn,  _cappedNs );
             // in an annoying twist of api, returns true on failure
-            return !applyOperation_inlock(&txn, ctx.db(), op, true);
+            return !applyOperation_inlock(&_txn, ctx.db(), op, true);
         }
 
         void run() {
-            OperationContextImpl txn;
-            Lock::DBWrite lk(txn.lockState(), _cappedNs);
+            Lock::DBWrite lk(_txn.lockState(), _cappedNs);
 
             BSONObj op = updateFail();
 
             Sync s("");
-            verify(!s.shouldRetry(&txn, op));
+            verify(!s.shouldRetry(&_txn, op));
         }
     };
 
@@ -393,7 +387,7 @@ namespace ReplSetTests {
         }
 
         void insert(OperationContext* txn) {
-            Client::Context ctx(cappedNs());
+            Client::Context ctx(txn, cappedNs());
             Database* db = ctx.db();
             Collection* coll = db->getCollection(txn, cappedNs());
             if (!coll) {
@@ -407,21 +401,19 @@ namespace ReplSetTests {
     public:
         virtual ~CappedUpdate() {}
         void run() {
-            OperationContextImpl txn;
-
             // RARELY shoud be once/128x
             for (int i=0; i<150; i++) {
-                insert(&txn);
+                insert(&_txn);
                 updateSucceed();
             }
 
-            DBDirectClient client(&txn);
+            DBDirectClient client(&_txn);
             int count = (int) client.count(cappedNs(), BSONObj());
             verify(count > 1);
 
             // check _id index created
-            Client::Context ctx(cappedNs());
-            Collection* collection = ctx.db()->getCollection( &txn, cappedNs() );
+            Client::Context ctx(&_txn, cappedNs());
+            Collection* collection = ctx.db()->getCollection( &_txn, cappedNs() );
             verify(collection->getIndexCatalog()->findIdIndex());
         }
     };
@@ -440,7 +432,6 @@ namespace ReplSetTests {
     public:
         virtual ~CappedInsert() {}
         void run() {
-            OperationContextImpl txn;
             // This will succeed, but not insert anything because they are changed to upserts
             for (int i=0; i<150; i++) {
                 insertSucceed();
@@ -448,8 +439,8 @@ namespace ReplSetTests {
 
             // this changed in 2.1.2
             // we now have indexes on capped collections
-            Client::Context ctx(cappedNs());
-            Collection* collection = ctx.db()->getCollection( &txn, cappedNs() );
+            Client::Context ctx(&_txn, cappedNs());
+            Collection* collection = ctx.db()->getCollection( &_txn, cappedNs() );
             verify(collection->getIndexCatalog()->findIdIndex());
         }
     };
@@ -541,13 +532,13 @@ namespace ReplSetTests {
             addInserts(100);
             applyOplog();
 
-            ASSERT_EQUALS(expected, static_cast<int>(client()->count(ns())));
+            ASSERT_EQUALS(expected, static_cast<int>(_client.count(ns())));
 
             drop();
             addVersionedInserts(100);
             applyOplog();
 
-            ASSERT_EQUALS(expected, static_cast<int>(client()->count(ns())));
+            ASSERT_EQUALS(expected, static_cast<int>(_client.count(ns())));
 
             drop();
             addUpdates();
diff --git a/src/mongo/dbtests/repltests.cpp b/src/mongo/dbtests/repltests.cpp
index eb1b45065ad..11338a61225 100644
--- a/src/mongo/dbtests/repltests.cpp
+++ b/src/mongo/dbtests/repltests.cpp
@@ -65,7 +65,7 @@ namespace ReplTests {
     public:
         Base() : _lk(_txn.lockState()),
                  _client(&_txn),
-                 _context(ns()) {
+                 _context(&_txn, ns()) {
 
             oldRepl();
             replSettings.replSet = "";
@@ -121,7 +121,7 @@ namespace ReplTests {
         }
         int count() const {
             Lock::GlobalWrite lk(_txn.lockState());
-            Client::Context ctx( ns() );
+            Client::Context ctx(&_txn,  ns() );
             Database* db = ctx.db();
             Collection* coll = db->getCollection( &_txn, ns() );
             if ( !coll ) {
@@ -140,7 +140,7 @@ namespace ReplTests {
         static int opCount() {
             OperationContextImpl txn;
             Lock::GlobalWrite lk(txn.lockState());
-            Client::Context ctx( cllNS() );
+            Client::Context ctx(&txn,  cllNS() );
 
             Database* db = ctx.db();
             Collection* coll = db->getCollection( &txn, cllNS() );
@@ -163,7 +163,7 @@ namespace ReplTests {
 
             vector< BSONObj > ops;
             {
-                Client::Context ctx( cllNS() );
+                Client::Context ctx(&txn,  cllNS() );
                 Database* db = ctx.db();
                 Collection* coll = db->getCollection( &txn, cllNS() );
 
@@ -176,7 +176,7 @@ namespace ReplTests {
                 delete it;
             }
             {
-                Client::Context ctx( ns() );
+                Client::Context ctx(&txn,  ns() );
                 BSONObjBuilder b;
                 b.append("host", "localhost");
                 b.appendTimestamp("syncedTo", 0);
@@ -192,7 +192,7 @@ namespace ReplTests {
         static void printAll( const char *ns ) {
             OperationContextImpl txn;
             Lock::GlobalWrite lk(txn.lockState());
-            Client::Context ctx( ns );
+            Client::Context ctx(&txn,  ns );
 
             Database* db = ctx.db();
             Collection* coll = db->getCollection( &txn, ns );
@@ -213,7 +213,7 @@ namespace ReplTests {
         static void deleteAll( const char *ns ) {
             OperationContextImpl txn;
             Lock::GlobalWrite lk(txn.lockState());
-            Client::Context ctx( ns );
+            Client::Context ctx(&txn,  ns );
 
             Database* db = ctx.db();
             Collection* coll = db->getCollection( &txn, ns );
@@ -235,7 +235,7 @@ namespace ReplTests {
         static void insert( const BSONObj &o ) {
             OperationContextImpl txn;
             Lock::GlobalWrite lk(txn.lockState());
-            Client::Context ctx( ns() );
+            Client::Context ctx(&txn,  ns() );
 
             Database* db = ctx.db();
             Collection* coll = db->getCollection( &txn, ns() );
diff --git a/src/mongo/dbtests/sharding.cpp b/src/mongo/dbtests/sharding.cpp
index d376a8fbaa0..797fb53cbbc 100644
--- a/src/mongo/dbtests/sharding.cpp
+++ b/src/mongo/dbtests/sharding.cpp
@@ -28,10 +28,11 @@
  *    then also delete it in the license file.
  */
 
-#include "mongo/pch.h"
+#include "mongo/platform/basic.h"
 
 #include "mongo/client/dbclientmockcursor.h"
 #include "mongo/client/parallel.h"
+#include "mongo/db/operation_context_impl.h"
 #include "mongo/dbtests/config_server_fixture.h"
 #include "mongo/dbtests/dbtests.h"
 #include "mongo/s/chunk_diff.h"
@@ -81,10 +82,11 @@ namespace ShardingTests {
     class ChunkManagerTest : public ConnectionString::ConnectionHook {
     public:
 
+        OperationContextImpl _txn;
         CustomDirectClient _client;
         Shard _shard;
 
-        ChunkManagerTest() {
+        ChunkManagerTest() : _client(&_txn) {
 
             DBException::traceExceptions = true;
 
@@ -131,7 +133,7 @@ namespace ShardingTests {
                                        double socketTimeout )
         {
             // Note - must be new, since it gets owned elsewhere
-            return new CustomDirectClient();
+            return new CustomDirectClient(&_txn);
         }
     };
 
diff --git a/src/mongo/dbtests/threadedtests.cpp b/src/mongo/dbtests/threadedtests.cpp
index 998ba2c2bed..0e36df8f43f 100644
--- a/src/mongo/dbtests/threadedtests.cpp
+++ b/src/mongo/dbtests/threadedtests.cpp
@@ -35,6 +35,7 @@
 
 #include "mongo/bson/util/atomic_int.h"
 #include "mongo/db/d_concurrency.h"
+#include "mongo/db/operation_context_impl.h"
 #include "mongo/dbtests/dbtests.h"
 #include "mongo/platform/atomic_word.h"
 #include "mongo/platform/bits.h"
@@ -109,7 +110,9 @@ namespace ThreadedTests {
                 // in _DEBUG builds on linux we mprotect each time a writelock
                 // is taken. That can greatly slow down this test if there are
                 // many open files
-                DBDirectClient db;
+                OperationContextImpl txn;
+                DBDirectClient db(&txn);
+
                 db.simpleCommand("admin", NULL, "closeAllDatabases");
             }
 
diff --git a/src/mongo/dbtests/updatetests.cpp b/src/mongo/dbtests/updatetests.cpp
index e048ebc2d9f..cbdcc346dc8 100644
--- a/src/mongo/dbtests/updatetests.cpp
+++ b/src/mongo/dbtests/updatetests.cpp
@@ -38,6 +38,7 @@
 #include "mongo/db/json.h"
 #include "mongo/db/lasterror.h"
 #include "mongo/db/ops/update.h"
+#include "mongo/db/operation_context_impl.h"
 #include "mongo/dbtests/dbtests.h"
 
 namespace UpdateTests {
@@ -45,27 +46,26 @@ namespace UpdateTests {
     class ClientBase {
     public:
         // NOTE: Not bothering to backup the old error record.
-        ClientBase() {
+        ClientBase() : _client(&_txn) {
             mongo::lastError.reset( new LastError() );
         }
         ~ClientBase() {
             mongo::lastError.release();
         }
+
     protected:
         void insert( const char *ns, BSONObj o ) {
-            client_.insert( ns, o );
+            _client.insert( ns, o );
         }
         void update( const char *ns, BSONObj q, BSONObj o, bool upsert = 0 ) {
-            client_.update( ns, Query( q ), o, upsert );
+            _client.update( ns, Query( q ), o, upsert );
         }
         bool error() {
-            return !client_.getPrevError().getField( "err" ).isNull();
+            return !_client.getPrevError().getField( "err" ).isNull();
         }
 
-        DBDirectClient& client() { return client_; }
-
-    private:
-        DBDirectClient client_;
+        OperationContextImpl _txn;
+        DBDirectClient _client;
     };
 
     class Fail : public ClientBase {
@@ -145,7 +145,7 @@ namespace UpdateTests {
     class SetBase : public ClientBase {
     public:
         ~SetBase() {
-            client().dropCollection( ns() );
+            _client.dropCollection( ns() );
         }
     protected:
         const char *ns() { return "unittests.updatetests.SetBase"; }
@@ -154,45 +154,45 @@ namespace UpdateTests {
     class SetNum : public SetBase {
     public:
         void run() {
-            client().insert( ns(), BSON( "a" << 1 ) );
-            client().update( ns(), BSON( "a" << 1 ), BSON( "$set" << BSON( "a" << 4 ) ) );
-            ASSERT( !client().findOne( ns(), BSON( "a" << 4 ) ).isEmpty() );
+            _client.insert( ns(), BSON( "a" << 1 ) );
+            _client.update( ns(), BSON( "a" << 1 ), BSON( "$set" << BSON( "a" << 4 ) ) );
+            ASSERT( !_client.findOne( ns(), BSON( "a" << 4 ) ).isEmpty() );
         }
     };
 
     class SetString : public SetBase {
     public:
         void run() {
-            client().insert( ns(), BSON( "a" << "b" ) );
-            client().update( ns(), BSON( "a" << "b" ), BSON( "$set" << BSON( "a" << "c" ) ) );
-            ASSERT( !client().findOne( ns(), BSON( "a" << "c" ) ).isEmpty() );
+            _client.insert( ns(), BSON( "a" << "b" ) );
+            _client.update( ns(), BSON( "a" << "b" ), BSON( "$set" << BSON( "a" << "c" ) ) );
+            ASSERT( !_client.findOne( ns(), BSON( "a" << "c" ) ).isEmpty() );
         }
     };
 
     class SetStringDifferentLength : public SetBase {
     public:
         void run() {
-            client().insert( ns(), BSON( "a" << "b" ) );
-            client().update( ns(), BSON( "a" << "b" ), BSON( "$set" << BSON( "a" << "cd" ) ) );
-            ASSERT( !client().findOne( ns(), BSON( "a" << "cd" ) ).isEmpty() );
+            _client.insert( ns(), BSON( "a" << "b" ) );
+            _client.update( ns(), BSON( "a" << "b" ), BSON( "$set" << BSON( "a" << "cd" ) ) );
+            ASSERT( !_client.findOne( ns(), BSON( "a" << "cd" ) ).isEmpty() );
         }
     };
 
     class SetStringToNum : public SetBase {
     public:
         void run() {
-            client().insert( ns(), BSON( "a" << "b" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a" << 5 ) ) );
-            ASSERT( !client().findOne( ns(), BSON( "a" << 5 ) ).isEmpty() );
+            _client.insert( ns(), BSON( "a" << "b" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a" << 5 ) ) );
+            ASSERT( !_client.findOne( ns(), BSON( "a" << 5 ) ).isEmpty() );
         }
     };
 
     class SetStringToNumInPlace : public SetBase {
     public:
         void run() {
-            client().insert( ns(), BSON( "a" << "bcd" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a" << 5.0 ) ) );
-            ASSERT( !client().findOne( ns(), BSON( "a" << 5.0 ) ).isEmpty() );
+            _client.insert( ns(), BSON( "a" << "bcd" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a" << 5.0 ) ) );
+            ASSERT( !_client.findOne( ns(), BSON( "a" << 5.0 ) ).isEmpty() );
         }
     };
 
@@ -200,13 +200,13 @@ namespace UpdateTests {
     public:
         void run() {
             // Try with upsert false first.
-            client().insert( ns(), BSONObj() /* empty document */);
-            client().update( ns(), Query(), BSON( "$setOnInsert" << BSON( "a" << 1 ) ), false );
-            ASSERT( client().findOne( ns(), BSON( "a" << 1 ) ).isEmpty() );
+            _client.insert( ns(), BSONObj() /* empty document */);
+            _client.update( ns(), Query(), BSON( "$setOnInsert" << BSON( "a" << 1 ) ), false );
+            ASSERT( _client.findOne( ns(), BSON( "a" << 1 ) ).isEmpty() );
 
             // Then with upsert true.
-            client().update( ns(), Query(), BSON( "$setOnInsert" << BSON( "a" << 1 ) ), true );
-            ASSERT( client().findOne( ns(), BSON( "a" << 1 ) ).isEmpty() );
+            _client.update( ns(), Query(), BSON( "$setOnInsert" << BSON( "a" << 1 ) ), true );
+            ASSERT( _client.findOne( ns(), BSON( "a" << 1 ) ).isEmpty() );
 
         }
     };
@@ -215,12 +215,12 @@ namespace UpdateTests {
     public:
         void run() {
             // Try with upsert false first.
-            client().update( ns(), Query(), BSON( "$setOnInsert" << BSON( "a" << 1 ) ), false );
-            ASSERT( client().findOne( ns(), BSON( "a" << 1 ) ).isEmpty() );
+            _client.update( ns(), Query(), BSON( "$setOnInsert" << BSON( "a" << 1 ) ), false );
+            ASSERT( _client.findOne( ns(), BSON( "a" << 1 ) ).isEmpty() );
 
             // Then with upsert true.
-            client().update( ns(), Query(), BSON( "$setOnInsert" << BSON( "a" << 1 ) ), true );
-            ASSERT( !client().findOne( ns(), BSON( "a" << 1 ) ).isEmpty() );
+            _client.update( ns(), Query(), BSON( "$setOnInsert" << BSON( "a" << 1 ) ), true );
+            ASSERT( !_client.findOne( ns(), BSON( "a" << 1 ) ).isEmpty() );
 
         }
     };
@@ -231,12 +231,12 @@ namespace UpdateTests {
             Query q("{a:1}");
 
             // Try with upsert false first.
-            client().update( ns(), q, BSON( "$setOnInsert" << BSON( "b" << 1 ) ), false );
-            ASSERT( client().findOne( ns(), BSON( "a" << 1 ) ).isEmpty() );
+            _client.update( ns(), q, BSON( "$setOnInsert" << BSON( "b" << 1 ) ), false );
+            ASSERT( _client.findOne( ns(), BSON( "a" << 1 ) ).isEmpty() );
 
             // Then with upsert true.
-            client().update( ns(), q, BSON( "$setOnInsert" << BSON( "b" << 1 ) ), true );
-            ASSERT( !client().findOne( ns(), BSON( "a" << 1 << "b" << 1) ).isEmpty() );
+            _client.update( ns(), q, BSON( "$setOnInsert" << BSON( "b" << 1 ) ), true );
+            ASSERT( !_client.findOne( ns(), BSON( "a" << 1 << "b" << 1) ).isEmpty() );
 
         }
     };
@@ -247,12 +247,12 @@ namespace UpdateTests {
             Query q("{a:1}"); // same field that we'll setOnInsert on
 
             // Try with upsert false first.
-            client().update( ns(), q, BSON( "$setOnInsert" << BSON( "a" << 2 ) ), false );
-            ASSERT( client().findOne( ns(), BSON( "a" << 1 ) ).isEmpty() );
+            _client.update( ns(), q, BSON( "$setOnInsert" << BSON( "a" << 2 ) ), false );
+            ASSERT( _client.findOne( ns(), BSON( "a" << 1 ) ).isEmpty() );
 
             // Then with upsert true.
-            client().update( ns(), q, BSON( "$setOnInsert" << BSON( "a" << 2 ) ), true );
-            ASSERT( !client().findOne( ns(), BSON( "a" << 2 ) ).isEmpty() );
+            _client.update( ns(), q, BSON( "$setOnInsert" << BSON( "a" << 2 ) ), true );
+            ASSERT( !_client.findOne( ns(), BSON( "a" << 2 ) ).isEmpty() );
 
         }
     };
@@ -261,18 +261,18 @@ namespace UpdateTests {
     public:
         void run() {
             BSONObj res = fromjson("{'_id':0, a:1}");
-            client().insert( ns(), res );
-            client().update( ns(), Query(), BSON( "$setOnInsert" << BSON( "b" << 1 ) ) );
-            ASSERT( client().findOne( ns(), BSON( "a" << 1 ) ).woCompare( res ) == 0 );
+            _client.insert( ns(), res );
+            _client.update( ns(), Query(), BSON( "$setOnInsert" << BSON( "b" << 1 ) ) );
+            ASSERT( _client.findOne( ns(), BSON( "a" << 1 ) ).woCompare( res ) == 0 );
         }
     };
 
     class SetOnInsertExisting : public SetBase {
     public:
         void run() {
-            client().insert( ns(), BSON( "a" << 1 ) );
-            client().update( ns(), Query(), BSON( "$setOnInsert" << BSON( "a" << 2 ) ) );
-            ASSERT( !client().findOne( ns(), BSON( "a" << 1 ) ).isEmpty() );
+            _client.insert( ns(), BSON( "a" << 1 ) );
+            _client.update( ns(), Query(), BSON( "$setOnInsert" << BSON( "a" << 2 ) ) );
+            ASSERT( !_client.findOne( ns(), BSON( "a" << 1 ) ).isEmpty() );
         }
     };
 
@@ -280,14 +280,14 @@ namespace UpdateTests {
     public:
         void run() {
             // Try with upsert false first.
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a" << 1 ) <<
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a" << 1 ) <<
                                                   "$setOnInsert" << BSON( "b" << 2 ) ), false );
-            ASSERT( client().findOne( ns(), BSON( "a" << 1 << "b" << 2 ) ).isEmpty() );
+            ASSERT( _client.findOne( ns(), BSON( "a" << 1 << "b" << 2 ) ).isEmpty() );
 
             // Then with upsert true.
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a" << 1 ) <<
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a" << 1 ) <<
                                                   "$setOnInsert" << BSON( "b" << 2 ) ), true );
-            ASSERT( !client().findOne( ns(), BSON( "a" << 1 << "b" << 2 ) ).isEmpty() );
+            ASSERT( !_client.findOne( ns(), BSON( "a" << 1 << "b" << 2 ) ).isEmpty() );
         }
     };
 
@@ -298,58 +298,58 @@ namespace UpdateTests {
             // parent unneccesarily.
             BSONObj initial = fromjson( "{'_id':0}" );
             BSONObj final = fromjson( "{'_id':0, d:1}" );
-            client().insert( ns(), initial );
-            client().update( ns(), initial, BSON( "$setOnInsert" << BSON( "a.b" << 1 ) <<
+            _client.insert( ns(), initial );
+            _client.update( ns(), initial, BSON( "$setOnInsert" << BSON( "a.b" << 1 ) <<
                                                   "$set" << BSON( "d" << 1 ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), initial ), final );
+            ASSERT_EQUALS( _client.findOne( ns(), initial ), final );
         }
     };
 
     class ModDotted : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{a:{b:4}}" ) );
-            client().update( ns(), Query(), BSON( "$inc" << BSON( "a.b" << 10 ) ) );
-            ASSERT( !client().findOne( ns(), BSON( "a.b" << 14 ) ).isEmpty() );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a.b" << 55 ) ) );
-            ASSERT( !client().findOne( ns(), BSON( "a.b" << 55 ) ).isEmpty() );
+            _client.insert( ns(), fromjson( "{a:{b:4}}" ) );
+            _client.update( ns(), Query(), BSON( "$inc" << BSON( "a.b" << 10 ) ) );
+            ASSERT( !_client.findOne( ns(), BSON( "a.b" << 14 ) ).isEmpty() );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a.b" << 55 ) ) );
+            ASSERT( !_client.findOne( ns(), BSON( "a.b" << 55 ) ).isEmpty() );
         }
     };
 
     class SetInPlaceDotted : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{a:{b:'cdef'}}" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a.b" << "llll" ) ) );
-            ASSERT( !client().findOne( ns(), BSON( "a.b" << "llll" ) ).isEmpty() );
+            _client.insert( ns(), fromjson( "{a:{b:'cdef'}}" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a.b" << "llll" ) ) );
+            ASSERT( !_client.findOne( ns(), BSON( "a.b" << "llll" ) ).isEmpty() );
         }
     };
 
     class SetRecreateDotted : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:{b:'cdef'}}" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a.b" << "lllll" ) ) );
-            ASSERT( client().findOne( ns(), BSON( "a.b" << "lllll" ) ).woCompare( fromjson( "{'_id':0,a:{b:'lllll'}}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0,a:{b:'cdef'}}" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a.b" << "lllll" ) ) );
+            ASSERT( _client.findOne( ns(), BSON( "a.b" << "lllll" ) ).woCompare( fromjson( "{'_id':0,a:{b:'lllll'}}" ) ) == 0 );
         }
     };
 
     class SetMissingDotted : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0}" ) );
-            client().update( ns(), BSONObj(), BSON( "$set" << BSON( "a.b" << "lllll" ) ) );
-            ASSERT( client().findOne( ns(), BSON( "a.b" << "lllll" ) ).woCompare( fromjson( "{'_id':0,a:{b:'lllll'}}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0}" ) );
+            _client.update( ns(), BSONObj(), BSON( "$set" << BSON( "a.b" << "lllll" ) ) );
+            ASSERT( _client.findOne( ns(), BSON( "a.b" << "lllll" ) ).woCompare( fromjson( "{'_id':0,a:{b:'lllll'}}" ) ) == 0 );
         }
     };
 
     class SetAdjacentDotted : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:{c:4}}" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a.b" << "lllll" ) ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:{c:4}}" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a.b" << "lllll" ) ) );
             ASSERT_EQUALS(
-                mutablebson::unordered( client().findOne( ns(), BSON( "a.b" << "lllll" ) ) ),
+                mutablebson::unordered( _client.findOne( ns(), BSON( "a.b" << "lllll" ) ) ),
                 mutablebson::unordered( fromjson( "{'_id':0,a:{b:'lllll',c:4}}" ) ) );
         }
     };
@@ -357,9 +357,9 @@ namespace UpdateTests {
     class IncMissing : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0}" ) );
-            client().update( ns(), Query(), BSON( "$inc" << BSON( "f" << 3.0 ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,f:3}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0}" ) );
+            _client.update( ns(), Query(), BSON( "$inc" << BSON( "f" << 3.0 ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,f:3}" ) ) == 0 );
         }
     };
 
@@ -368,7 +368,7 @@ namespace UpdateTests {
 
         string s() {
             stringstream ss;
-            auto_ptr<DBClientCursor> cc = client().query( ns() , Query().sort( BSON( "_id" << 1 ) ) );
+            auto_ptr<DBClientCursor> cc = _client.query( ns() , Query().sort( BSON( "_id" << 1 ) ) );
             bool first = true;
             while ( cc->more() ) {
                 if ( first ) first = false;
@@ -381,18 +381,18 @@ namespace UpdateTests {
         }
 
         void run() {
-            client().insert( ns(), BSON( "_id" << 1 << "x" << 1 ) );
-            client().insert( ns(), BSON( "_id" << 2 << "x" << 5 ) );
+            _client.insert( ns(), BSON( "_id" << 1 << "x" << 1 ) );
+            _client.insert( ns(), BSON( "_id" << 2 << "x" << 5 ) );
 
             ASSERT_EQUALS( "1,5" , s() );
 
-            client().update( ns() , BSON( "_id" << 1 ) , BSON( "$inc" << BSON( "x" << 1 ) ) );
+            _client.update( ns() , BSON( "_id" << 1 ) , BSON( "$inc" << BSON( "x" << 1 ) ) );
             ASSERT_EQUALS( "2,5" , s() );
 
-            client().update( ns() , BSONObj() , BSON( "$inc" << BSON( "x" << 1 ) ) );
+            _client.update( ns() , BSONObj() , BSON( "$inc" << BSON( "x" << 1 ) ) );
             ASSERT_EQUALS( "3,5" , s() );
 
-            client().update( ns() , BSONObj() , BSON( "$inc" << BSON( "x" << 1 ) ) , false , true );
+            _client.update( ns() , BSONObj() , BSON( "$inc" << BSON( "x" << 1 ) ) , false , true );
             ASSERT_EQUALS( "4,6" , s() );
 
         }
@@ -401,10 +401,10 @@ namespace UpdateTests {
     class UnorderedNewSet : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0}" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "f.g.h" << 3.0 << "f.g.a" << 2.0 ) ) );
+            _client.insert( ns(), fromjson( "{'_id':0}" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "f.g.h" << 3.0 << "f.g.a" << 2.0 ) ) );
             ASSERT_EQUALS(
-                mutablebson::unordered( client().findOne( ns(), Query() ) ),
+                mutablebson::unordered( _client.findOne( ns(), Query() ) ),
                 mutablebson::unordered( fromjson( "{'_id':0,f:{g:{a:2,h:3}}}" ) ) );
         }
     };
@@ -412,10 +412,10 @@ namespace UpdateTests {
     class UnorderedNewSetAdjacent : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0}" ) );
-            client().update( ns(), BSONObj(), BSON( "$set" << BSON( "f.g.h.b" << 3.0 << "f.g.a.b" << 2.0 ) ) );
+            _client.insert( ns(), fromjson( "{'_id':0}" ) );
+            _client.update( ns(), BSONObj(), BSON( "$set" << BSON( "f.g.h.b" << 3.0 << "f.g.a.b" << 2.0 ) ) );
             ASSERT_EQUALS(
-                mutablebson::unordered( client().findOne( ns(), Query() ) ),
+                mutablebson::unordered( _client.findOne( ns(), Query() ) ),
                 mutablebson::unordered( fromjson( "{'_id':0,f:{g:{a:{b:2},h:{b:3}}}}" ) ) );
         }
     };
@@ -423,161 +423,161 @@ namespace UpdateTests {
     class ArrayEmbeddedSet : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,z:[4,'b']}" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "z.0" << "a" ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0,z:['a','b']}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,z:[4,'b']}" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "z.0" << "a" ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0,z:['a','b']}" ) );
         }
     };
 
     class AttemptEmbedInExistingNum : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:1}" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a.b" << 1 ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:1}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0,a:1}" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a.b" << 1 ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:1}" ) ) == 0 );
         }
     };
 
     class AttemptEmbedConflictsWithOtherSet : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0}" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a" << 2 << "a.b" << 1 ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0}" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a" << 2 << "a.b" << 1 ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0}" ) );
         }
     };
 
     class ModMasksEmbeddedConflict : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:{b:2}}" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a" << 2 << "a.b" << 1 ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{b:2}}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0,a:{b:2}}" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a" << 2 << "a.b" << 1 ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{b:2}}" ) ) == 0 );
         }
     };
 
     class ModOverwritesExistingObject : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:{b:2}}" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a" << BSON( "c" << 2 ) ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{c:2}}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0,a:{b:2}}" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a" << BSON( "c" << 2 ) ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{c:2}}" ) ) == 0 );
         }
     };
 
     class InvalidEmbeddedSet : public Fail {
     public:
         virtual void doIt() {
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a." << 1 ) ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a." << 1 ) ) );
         }
     };
 
     class UpsertMissingEmbedded : public SetBase {
     public:
         void run() {
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a.b" << 1 ) ), true );
-            ASSERT( !client().findOne( ns(), QUERY( "a.b" << 1 ) ).isEmpty() );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a.b" << 1 ) ), true );
+            ASSERT( !_client.findOne( ns(), QUERY( "a.b" << 1 ) ).isEmpty() );
         }
     };
 
     class Push : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1]}" ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << 5 ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[1,5]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1]}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << 5 ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[1,5]}" ) );
         }
     };
 
     class PushInvalidEltType : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:1}" ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << 5 ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:1}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0,a:1}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << 5 ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:1}" ) ) == 0 );
         }
     };
 
     class PushConflictsWithOtherMod : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1]}" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a" << 1 ) <<"$push" << BSON( "a" << 5 ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:[1]}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1]}" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a" << 1 ) <<"$push" << BSON( "a" << 5 ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:[1]}" ) ) == 0 );
         }
     };
 
     class PushFromNothing : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0}" ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << 5 ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[5]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << 5 ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[5]}" ) );
         }
     };
 
     class PushFromEmpty : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[]}" ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << 5 ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:[5]}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[]}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << 5 ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:[5]}" ) ) == 0 );
         }
     };
 
     class PushInsideNothing : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0}" ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a.b" << 5 ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{b:[5]}}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a.b" << 5 ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{b:[5]}}" ) ) == 0 );
         }
     };
 
     class CantPushInsideOtherMod : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0}" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a" << BSONObj() ) << "$push" << BSON( "a.b" << 5 ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0}" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a" << BSONObj() ) << "$push" << BSON( "a.b" << 5 ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0}" ) ) == 0 );
         }
     };
 
     class CantPushTwice : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[]}" ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << 4 ) << "$push" << BSON( "a" << 5 ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:[]}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[]}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << 4 ) << "$push" << BSON( "a" << 5 ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:[]}" ) ) == 0 );
         }
     };
 
     class SetEncapsulationConflictsWithExistingType : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:{b:4}}" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a.b.c" << 4.0 ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{b:4}}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0,a:{b:4}}" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a.b.c" << 4.0 ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{b:4}}" ) ) == 0 );
         }
     };
 
     class CantPushToParent : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:{b:4}}" ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << 4.0 ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{b:4}}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0,a:{b:4}}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << 4.0 ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{b:4}}" ) ) == 0 );
         }
     };
 
     class PushEachSimple : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1]}" ) );
             // { $push : { a : { $each : [ 2, 3 ] } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( 2 << 3 ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[1,2,3]}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[1,2,3]}" ) );
         }
 
     };
@@ -585,11 +585,11 @@ namespace UpdateTests {
     class PushEachFromEmpty : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[]}" ) );
             // { $push : { a : { $each : [ 1, 2, 3 ] } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( 1 << 2 << 3 ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[1,2,3]}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[1,2,3]}" ) );
         }
 
     };
@@ -597,189 +597,189 @@ namespace UpdateTests {
     class PushSliceBelowFull : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1]}" ) );
             // { $push : { a : { $each : [ 2 ] , $slice : -3 } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( 2 ) << "$slice" << -3 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[1,2]}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[1,2]}" ) );
         }
     };
 
     class PushSliceReachedFullExact : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1]}" ) );
             // { $push : { a : { $each : [ 2 ] , $slice : -2 } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( 2 ) << "$slice" << -2 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[1,2]}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[1,2]}" ) );
         }
     };
 
     class PushSliceReachedFullWithEach : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1]}" ) );
             // { $push : { a : { $each : [ 2 , 3 ] , $slice : -2 } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( 2 << 3 ) << "$slice" << -2 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[2,3]}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[2,3]}" ) );
         }
     };
 
     class PushSliceReachedFullWithBoth : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
             // { $push : { a : { $each : [ 3 ] , $slice : -2 } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( 3 ) << "$slice" << -2 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[2,3]}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[2,3]}" ) );
         }
     };
 
     class PushSliceToZero : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
             // { $push : { a : { $each : [ 3 ] , $slice : 0 } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( 3 ) << "$slice" << 0 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[]}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[]}" ) );
         }
     };
 
     class PushSliceToZeroFromNothing : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0}" ) );
             // { $push : { a : { $each : [ 3 ] , $slice : 0 } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( 3 ) << "$slice" << 0 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[]}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[]}" ) );
         }
     };
 
     class PushSliceFromNothing : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0}" ) );
             // { $push : { a : { $each : [ 1 , 2 ] , $slice : -3 } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( 1 << 2 ) << "$slice" << -3 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[1,2]}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[1,2]}" ) );
         }
     };
 
     class PushSliceLongerThanSliceFromNothing : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0}" ) );
             // { $push : { a : { $each : [ 1 , 2 , 3 ] , $slice : -2 } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( 1 << 2 << 3 ) << "$slice" << -2 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[2,3]}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[2,3]}" ) );
         }
     };
 
     class PushSliceFromEmpty : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[]}" ) );
             // { $push : { a : { $each : [ 1 ] , $slice : -3 } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( 1 ) << "$slice" << -3 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[1]}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[1]}" ) );
         }
     };
 
     class PushSliceLongerThanSliceFromEmpty : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[]}" ) );
             // { $push : { a : { $each : [ 1 , 2 , 3 ] , $slice : -2 } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( 1 << 2 << 3 ) << "$slice" << -2 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[2,3]}" ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson( "{'_id':0,a:[2,3]}" ) );
         }
     };
 
     class PushSliceTwoFields : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1,2],b:[3,4]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1,2],b:[3,4]}" ) );
             // { $push: { a: { $each: [ 5 ] , $slice : -2 }, { b: $each: [ 6 ] , $slice: -1 } } }
             BSONObj objA = BSON( "$each" << BSON_ARRAY( 5 ) << "$slice" << -2 );
             BSONObj objB = BSON( "$each" << BSON_ARRAY( 6 ) << "$slice" << -1 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << objA << "b" << objB ) ) );
-            ASSERT_EQUALS( client().findOne( ns(), Query() ) , fromjson("{'_id':0,a:[2,5],b:[6]}"));
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << objA << "b" << objB ) ) );
+            ASSERT_EQUALS( _client.findOne( ns(), Query() ) , fromjson("{'_id':0,a:[2,5],b:[6]}"));
         }
     };
 
     class PushSliceAndNormal : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1,2],b:[3]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1,2],b:[3]}" ) );
             // { $push : { a : { $each : [ 5 ] , $slice : -2 } , { b : 4 } }
             BSONObj objA = BSON( "$each" << BSON_ARRAY( 5 ) << "$slice" << -2 );
-            client().update( ns(), Query(), BSON("$push" << BSON("a" << objA << "b" << 4)));
-            ASSERT_EQUALS(client().findOne(ns(), Query()) , fromjson("{'_id':0,a:[2,5],b:[3,4]}"));
+            _client.update( ns(), Query(), BSON("$push" << BSON("a" << objA << "b" << 4)));
+            ASSERT_EQUALS(_client.findOne(ns(), Query()) , fromjson("{'_id':0,a:[2,5],b:[3,4]}"));
         }
     };
 
     class PushSliceTwoFieldsConflict : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1],b:[3]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1],b:[3]}" ) );
             // { $push: { a: { $each: [ 5 ] , $slice: -2 } , { a: $each: [ 6 ] , $slice: -1 } } }
             BSONObj objA = BSON( "$each" << BSON_ARRAY( 5 ) << "$slice" << -2 );
             BSONObj other = BSON( "$each" << BSON_ARRAY( 6 ) << "$slice" << -1 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << objA << "a" << other ) ) );
-            ASSERT(client().findOne( ns(), Query()).woCompare(fromjson("{'_id':0,a:[1],b:[3]}"))==0);
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << objA << "a" << other ) ) );
+            ASSERT(_client.findOne( ns(), Query()).woCompare(fromjson("{'_id':0,a:[1],b:[3]}"))==0);
         }
     };
 
     class PushSliceAndNormalConflict : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1],b:[3]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1],b:[3]}" ) );
             // { $push : { a : { $each : [ 5 ] , $slice : -2 } , { a : 4 } } }
             BSONObj objA = BSON( "$each" << BSON_ARRAY( 5 ) << "$slice" << -2 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << objA << "a" << 4 ) ) );
-            ASSERT(client().findOne( ns(), Query()).woCompare(fromjson("{'_id':0,a:[1],b:[3]}"))==0);
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << objA << "a" << 4 ) ) );
+            ASSERT(_client.findOne( ns(), Query()).woCompare(fromjson("{'_id':0,a:[1],b:[3]}"))==0);
         }
     };
 
     class PushSliceInvalidEachType : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
             // { $push : { a : { $each : 3 , $slice : -2 } } }
             BSONObj pushObj = BSON( "$each" << 3 << "$slice" << -2 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT( client().findOne(ns(), Query()).woCompare(fromjson("{'_id':0,a:[1,2]}")) == 0);
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT( _client.findOne(ns(), Query()).woCompare(fromjson("{'_id':0,a:[1,2]}")) == 0);
         }
     };
 
     class PushSliceInvalidSliceType : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
             // { $push : { a : { $each : [ 3 ], $slice : [ -2 ] } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY(3) << "$slice" << BSON_ARRAY(-2) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare(fromjson("{'_id':0,a:[1,2]}")) == 0);
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare(fromjson("{'_id':0,a:[1,2]}")) == 0);
         }
     };
 
     class PushSliceInvalidSliceValue : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
             // { $push : { a : { $each : [ 3 ], $slice : 2 } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY(3) << "$slice" << 2 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare(fromjson("{'_id':0,a:[1,2]}")) == 0);
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare(fromjson("{'_id':0,a:[1,2]}")) == 0);
         }
     };
 
@@ -787,33 +787,33 @@ namespace UpdateTests {
     class PushSliceInvalidSliceDouble : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
             // { $push : { a : { $each : [ 3 ], $slice : -2.1 } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY(3) << "$slice" << -2.1 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare(fromjson("{'_id':0,a:[1,2]}")) == 0);
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare(fromjson("{'_id':0,a:[1,2]}")) == 0);
         }
     };
 
     class PushSliceValidSliceDouble : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
             // { $push : { a : { $each : [ 3 ], $slice : -2.0 } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY(3) << "$slice" << -2.0 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT_EQUALS(client().findOne(ns(), Query()) , fromjson("{'_id':0,a:[2,3]}"));
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT_EQUALS(_client.findOne(ns(), Query()) , fromjson("{'_id':0,a:[2,3]}"));
         }
     };
 
     class PushSliceInvalidSlice : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,a:[1,2]}" ) );
             // { $push : { a : { $each : [ 3 ], $xxxx :  2 } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY(3) << "$xxxx" << 2 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare(fromjson("{'_id':0,a:[1,2]}")) == 0);
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "a" << pushObj ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare(fromjson("{'_id':0,a:[1,2]}")) == 0);
         }
     };
 
@@ -826,7 +826,7 @@ namespace UpdateTests {
     class PushSortBase : public ClientBase {
     public:
         ~PushSortBase() {
-            client().dropCollection( ns() );
+            _client.dropCollection( ns() );
         }
 
     protected:
@@ -904,8 +904,8 @@ namespace UpdateTests {
 
         void check( BSONObj expected ) {
             std::cout << expected.toString() << std::endl;
-            std::cout << client().findOne( ns(), Query() ) << std::endl;
-            ASSERT( client().findOne( ns(), Query() ).woCompare( expected ) == 0 );
+            std::cout << _client.findOne( ns(), Query() ) << std::endl;
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( expected ) == 0 );
         }
 
     private:
@@ -930,24 +930,24 @@ namespace UpdateTests {
             // BOTTOMK_DESC: $push: { x: { $each: [ {a:2,b:2} ], $slice:3, $sort: { b:-1 } } }
 
             for ( int i = 0; i < 2; i++ ) { // i < 4 when we have positive $slice
-                client().dropCollection( ns() );
-                client().insert( ns(), fromjson( "{'_id':0,x:[{a:1,b:1}]}" ) );
+                _client.dropCollection( ns() );
+                _client.insert( ns(), fromjson( "{'_id':0,x:[{a:1,b:1}]}" ) );
 
                 BSONObj result;
                 BSONObj expected;
                 switch ( i ) {
                 case TOPK_ASC:
                 case BOTTOMK_ASC:
-                    client().update( ns(), Query(), getUpdate(i) );
-                    result = client().findOne( ns(), Query() );
+                    _client.update( ns(), Query(), getUpdate(i) );
+                    result = _client.findOne( ns(), Query() );
                     expected = fromjson( "{'_id':0,x:[{a:1,b:1},{a:2,b:2}]}" );
                     ASSERT_EQUALS( result, expected );
                     break;
 
                 case TOPK_DESC:
                 case BOTTOMK_DESC:
-                    client().update( ns(), Query(), getUpdate(i) );
-                    result = client().findOne( ns(), Query() );
+                    _client.update( ns(), Query(), getUpdate(i) );
+                    result = _client.findOne( ns(), Query() );
                     expected =  fromjson( "{'_id':0,x:[{a:2,b:2},{a:1,b:1}]}" ) ;
                     ASSERT_EQUALS( result, expected );
                     break;
@@ -971,24 +971,24 @@ namespace UpdateTests {
             // BOTTOMK_DESC: $push: { x: { $each: [ {a:2,b:2} ], $slice:2, $sort: { b:-1 } } }
 
             for ( int i = 0; i < 2; i++ ) {  // i < 4 when we have positive $slice
-                client().dropCollection( ns() );
-                client().insert( ns(), fromjson( "{'_id':0,x:[{a:1,b:1}]}" ) );
+                _client.dropCollection( ns() );
+                _client.insert( ns(), fromjson( "{'_id':0,x:[{a:1,b:1}]}" ) );
 
                 BSONObj result;
                 BSONObj expected;
                 switch (i) {
                 case TOPK_ASC:
                 case BOTTOMK_ASC:
-                    client().update( ns(), Query(), getUpdate(i) );
-                    result = client().findOne( ns(), Query() );
+                    _client.update( ns(), Query(), getUpdate(i) );
+                    result = _client.findOne( ns(), Query() );
                     expected = fromjson( "{'_id':0,x:[{a:1,b:1},{a:2,b:2}]}" );
                     ASSERT_EQUALS( result, expected );
                     break;
 
                 case TOPK_DESC:
                 case BOTTOMK_DESC:
-                    client().update( ns(), Query(), getUpdate(i) );
-                    result = client().findOne( ns(), Query() );
+                    _client.update( ns(), Query(), getUpdate(i) );
+                    result = _client.findOne( ns(), Query() );
                     expected = fromjson( "{'_id':0,x:[{a:2,b:2},{a:1,b:1}]}" );
                     ASSERT_EQUALS( result, expected );
                     break;
@@ -1012,22 +1012,22 @@ namespace UpdateTests {
             // BOTTOMK_DESC: $push: { x: { $each: [ {a:2,b:2} ], $slice:2, $sort: { b:-1 } } }
 
             for ( int i = 0; i < 2; i++ ) {  // i < 4 when we have positive $slice
-                client().dropCollection( ns() );
-                client().insert( ns(), fromjson( "{'_id':0,x:[{a:1,b:1},{a:3,b:3}]}" ) );
+                _client.dropCollection( ns() );
+                _client.insert( ns(), fromjson( "{'_id':0,x:[{a:1,b:1},{a:3,b:3}]}" ) );
 
                 BSONObj result;
                 BSONObj expected;
                 switch ( i ) {
                 case TOPK_ASC:
-                    client().update( ns(), Query(), getUpdate(i) );
-                    result = client().findOne( ns(), Query() );
+                    _client.update( ns(), Query(), getUpdate(i) );
+                    result = _client.findOne( ns(), Query() );
                     expected = fromjson( "{'_id':0,x:[{a:2,b:2},{a:3,b:3}]}" );
                     ASSERT_EQUALS( result, expected );
                     break;
 
                 case TOPK_DESC:
-                    client().update( ns(), Query(), getUpdate(i) );
-                    result = client().findOne( ns(), Query() );
+                    _client.update( ns(), Query(), getUpdate(i) );
+                    result = _client.findOne( ns(), Query() );
                     expected = fromjson( "{'_id':0,x:[{a:2,b:2},{a:1,b:1}]}" );
                     ASSERT_EQUALS( result, expected );
                     break;
@@ -1056,14 +1056,14 @@ namespace UpdateTests {
             // BOTTOMK_DESC: $push: { x: { $each: [ {a:2,b:2} ], $slice:0, $sort: { b:-1 } } }
 
             for ( int i = 0; i < 2; i++ ) {  // i < 4 when we have positive $slice
-                client().dropCollection( ns() );
-                client().insert( ns(), fromjson( "{'_id':0,x:[{a:1,b:1},{a:3,b:3}]}" ) );
+                _client.dropCollection( ns() );
+                _client.insert( ns(), fromjson( "{'_id':0,x:[{a:1,b:1},{a:3,b:3}]}" ) );
 
                 BSONObj result;
                 BSONObj expected;
 
-                client().update( ns(), Query(), getUpdate(i) );
-                result = client().findOne( ns(), Query() );
+                _client.update( ns(), Query(), getUpdate(i) );
+                result = _client.findOne( ns(), Query() );
                 expected = fromjson( "{'_id':0,x:[]}" );
                 ASSERT_EQUALS( result, expected );
             }
@@ -1085,14 +1085,14 @@ namespace UpdateTests {
             // BOTTOMK_DESC: $push: { x: { $each: [ {a:2,b:2} ], $slice:0, $sort: { b:-1 } } }
 
             for ( int i = 0; i < 2; i++ ) {  // i < 4 when we have positive $slice
-                client().dropCollection( ns() );
-                client().insert( ns(), fromjson( "{'_id':0}" ) );
+                _client.dropCollection( ns() );
+                _client.insert( ns(), fromjson( "{'_id':0}" ) );
 
                 BSONObj result;
                 BSONObj expected;
 
-                client().update( ns(), Query(), getUpdate(i) );
-                result = client().findOne( ns(), Query() );
+                _client.update( ns(), Query(), getUpdate(i) );
+                result = _client.findOne( ns(), Query() );
                 expected = fromjson( "{'_id':0,x:[]}" );
                 ASSERT_EQUALS( result, expected );
             }
@@ -1116,24 +1116,24 @@ namespace UpdateTests {
             // BOTTOMK_DESC: $push: { x: { $each: [ <genarray> ], $slice:2, $sort: { b:-1 } } }
 
             for ( int i = 0; i < 2; i++ ) {  // i < 4 when we have positive $slice
-                client().dropCollection( ns() );
-                client().insert( ns(), fromjson( "{'_id':0}" ) );
+                _client.dropCollection( ns() );
+                _client.insert( ns(), fromjson( "{'_id':0}" ) );
 
                 BSONObj result;
                 BSONObj expected;
                 switch (i) {
                 case TOPK_ASC:
                 case BOTTOMK_ASC:
-                    client().update( ns(), Query(), getUpdate(i) );
-                    result = client().findOne( ns(), Query() );
+                    _client.update( ns(), Query(), getUpdate(i) );
+                    result = _client.findOne( ns(), Query() );
                     expected = fromjson( "{'_id':0,x:[{a:1,b:1},{a:2,b:2}]}" );
                     ASSERT_EQUALS( result, expected );
                     break;
 
                 case TOPK_DESC:
                 case BOTTOMK_DESC:
-                    client().update( ns(), Query(), getUpdate(i) );
-                    result = client().findOne( ns(), Query() );
+                    _client.update( ns(), Query(), getUpdate(i) );
+                    result = _client.findOne( ns(), Query() );
                     expected = fromjson( "{'_id':0,x:[{a:2,b:2},{a:1,b:1}]}" );
                     ASSERT_EQUALS( result, expected );
                     break;
@@ -1158,22 +1158,22 @@ namespace UpdateTests {
             // BOTTOMK_DESC: $push: { x: { $each: [ <genarray> ], $slice:2, $sort: { b:-1 } } }
 
             for ( int i = 0; i < 2; i++ ) {  // i < 4 when we have positive $slice
-                client().dropCollection( ns() );
-                client().insert( ns(), fromjson( "{'_id':0}" ) );
+                _client.dropCollection( ns() );
+                _client.insert( ns(), fromjson( "{'_id':0}" ) );
 
                 BSONObj result;
                 BSONObj expected;
                 switch (i) {
                 case TOPK_ASC:
-                    client().update( ns(), Query(), getUpdate(i) );
-                    result = client().findOne( ns(), Query() );
+                    _client.update( ns(), Query(), getUpdate(i) );
+                    result = _client.findOne( ns(), Query() );
                     expected = fromjson( "{'_id':0,x:[{a:2,b:2},{a:3,b:3}]}" );
                     ASSERT_EQUALS( result, expected );
                     break;
 
                 case TOPK_DESC:
-                    client().update( ns(), Query(), getUpdate(i) );
-                    result = client().findOne( ns(), Query() );
+                    _client.update( ns(), Query(), getUpdate(i) );
+                    result = _client.findOne( ns(), Query() );
                     expected = fromjson( "{'_id':0,x:[{a:2,b:2},{a:1,b:1}]}" );
                     ASSERT_EQUALS( result, expected );
                     break;
@@ -1203,24 +1203,24 @@ namespace UpdateTests {
             // BOTTOMK_DESC: $push: { x: { $each: [ <genarray> ], $slice:2, $sort: { b:-1 } } }
 
             for ( int i = 0; i < 2; i++ ) {  // i < 4 when we have positive $slice
-                client().dropCollection( ns() );
-                client().insert( ns(), fromjson( "{'_id':0,x:[]}" ) );
+                _client.dropCollection( ns() );
+                _client.insert( ns(), fromjson( "{'_id':0,x:[]}" ) );
 
                 BSONObj result;
                 BSONObj expected;
                 switch (i) {
                 case TOPK_ASC:
                 case BOTTOMK_ASC:
-                    client().update( ns(), Query(), getUpdate(i) );
-                    result = client().findOne( ns(), Query() );
+                    _client.update( ns(), Query(), getUpdate(i) );
+                    result = _client.findOne( ns(), Query() );
                     expected = fromjson( "{'_id':0,x:[{a:1,b:1},{a:2,b:2}]}" );
                     ASSERT_EQUALS( result, expected );
                     break;
 
                 case TOPK_DESC:
                 case BOTTOMK_DESC:
-                    client().update( ns(), Query(), getUpdate(i) );
-                    result = client().findOne( ns(), Query() );
+                    _client.update( ns(), Query(), getUpdate(i) );
+                    result = _client.findOne( ns(), Query() );
                     expected = fromjson( "{'_id':0,x:[{a:2,b:2},{a:1,b:1}]}" );
                     ASSERT_EQUALS( result, expected );
                     break;
@@ -1245,22 +1245,22 @@ namespace UpdateTests {
             // BOTTOMK_DESC: $push: { x: { $each: [ <genarray> ], $slice:2, $sort: { b:-1 } } }
 
             for ( int i = 0; i < 2; i++ ) {  // i < 4 when we have positive $slice
-                client().dropCollection( ns() );
-                client().insert( ns(), fromjson( "{'_id':0,x:[]}" ) );
+                _client.dropCollection( ns() );
+                _client.insert( ns(), fromjson( "{'_id':0,x:[]}" ) );
 
                 BSONObj result;
                 BSONObj expected;
                 switch (i) {
                 case TOPK_ASC:
-                    client().update( ns(), Query(), getUpdate(i) );
-                    result = client().findOne( ns(), Query() );
+                    _client.update( ns(), Query(), getUpdate(i) );
+                    result = _client.findOne( ns(), Query() );
                     expected = fromjson( "{'_id':0,x:[{a:2,b:2},{a:3,b:3}]}" );
                     ASSERT_EQUALS( result, expected );
                     break;
 
                 case TOPK_DESC:
-                    client().update( ns(), Query(), getUpdate(i) );
-                    result = client().findOne( ns(), Query() );
+                    _client.update( ns(), Query(), getUpdate(i) );
+                    result = _client.findOne( ns(), Query() );
                     expected = fromjson( "{'_id':0,x:[{a:2,b:2},{a:1,b:1}]}" );
                     ASSERT_EQUALS( result, expected );
                     break;
@@ -1416,14 +1416,14 @@ namespace UpdateTests {
             // catch bad patterns, we have to write updated that use them.
 
             BSONObj expected = fromjson( "{'_id':0,x:[{a:1}, {a:2}]}" );
-            client().insert( ns(), expected );
+            _client.insert( ns(), expected );
 
             // { $push : { x : { $each : [ {a:3} ], $slice:-2, $sort : {a..d:1} } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( BSON( "a" << 3 ) ) <<
                                     "$slice" << -2 <<
                                     "$sort" << BSON( "a..d" << 1 ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
-            BSONObj result = client().findOne( ns(), Query() );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
+            BSONObj result = _client.findOne( ns(), Query() );
             ASSERT_EQUALS( result, expected );
 
 
@@ -1431,32 +1431,32 @@ namespace UpdateTests {
             pushObj = BSON( "$each" << BSON_ARRAY( BSON( "a" << 3 ) ) <<
                                     "$slice" << -2 <<
                                     "$sort" << BSON( "a." << 1 ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
-            result = client().findOne( ns(), Query() );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
+            result = _client.findOne( ns(), Query() );
             ASSERT_EQUALS( result, expected );
 
             // { $push : { x : { $each : [ {a:3} ], $slice:-2, $sort : {.b:1} } } }
             pushObj = BSON( "$each" << BSON_ARRAY( BSON( "a" << 3 ) ) <<
                                     "$slice" << -2 <<
                                     "$sort" << BSON( ".b" << 1 ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
-            result = client().findOne( ns(), Query() );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
+            result = _client.findOne( ns(), Query() );
             ASSERT_EQUALS( result, expected );
 
             // { $push : { x : { $each : [ {a:3} ], $slice:-2, $sort : {.:1} } } }
             pushObj = BSON( "$each" << BSON_ARRAY( BSON( "a" << 3 ) ) <<
                                     "$slice" << -2 <<
                                     "$sort" << BSON( "." << 1 ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
-            result = client().findOne( ns(), Query() );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
+            result = _client.findOne( ns(), Query() );
             ASSERT_EQUALS( result, expected );
 
             // { $push : { x : { $each : [ {a:3} ], $slice:-2, $sort : {'':1} } } }
             pushObj = BSON( "$each" << BSON_ARRAY( BSON( "a" << 3 ) ) <<
                                     "$slice" << -2 <<
                                     "$sort" << BSON( "" << 1 ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
-            result = client().findOne( ns(), Query() );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
+            result = _client.findOne( ns(), Query() );
             ASSERT_EQUALS( result, expected );
         }
     };
@@ -1465,13 +1465,13 @@ namespace UpdateTests {
     public:
         void run() {
             BSONObj expected = fromjson( "{'_id':0,x:[{a:1},{a:2}]}" );
-            client().insert( ns(), expected );
+            _client.insert( ns(), expected );
             // { $push : { x : { $each : [ 3 ], $slice:-2, $sort : {a:1} } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( 3 ) <<
                                     "$slice" << -2 <<
                                     "$sort" << BSON( "a" << 1 ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
-            BSONObj result = client().findOne( ns(), Query() );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
+            BSONObj result = _client.findOne( ns(), Query() );
             ASSERT_EQUALS( result, expected );
         }
     };
@@ -1480,13 +1480,13 @@ namespace UpdateTests {
     public:
         void run() {
             BSONObj expected = fromjson( "{'_id':0,x:[{a:1},{a:2}]}" );
-            client().insert( ns(), expected );
+            _client.insert( ns(), expected );
             // { $push : { x : { $each : [ {a:3} ], $slice:-2, $sort : 2} } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( BSON( "a" << 3 ) ) <<
                                     "$slice" << -2 <<
                                     "$sort" << 2 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
-            BSONObj result = client().findOne( ns(), Query() );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
+            BSONObj result = _client.findOne( ns(), Query() );
             ASSERT_EQUALS( result, expected );
         }
     };
@@ -1495,13 +1495,13 @@ namespace UpdateTests {
     public:
         void run() {
             BSONObj expected = fromjson( "{'_id':0,x:[{a:1},{a:2}]}" );
-            client().insert( ns(), expected );
+            _client.insert( ns(), expected );
             // { $push : { x : { $each : [ {a:3} ], $slice:2, $sort : {a:1} } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( BSON( "a" << 3 ) ) <<
                                     "$slice" << 2 <<
                                     "$sort" << BSON( "a" << 1 ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
-            BSONObj result = client().findOne( ns(), Query() );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
+            BSONObj result = _client.findOne( ns(), Query() );
             ASSERT_EQUALS( result, expected );
         }
     };
@@ -1510,13 +1510,13 @@ namespace UpdateTests {
     public:
         void run() {
             BSONObj expected = fromjson( "{'_id':0,x:[{a:1},{a:2}]}" );
-            client().insert( ns(), expected );
+            _client.insert( ns(), expected );
             // { $push : { x : { $each : [ {a:3} ], $slice:-2.1, $sort : {a:1} } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( BSON( "a" << 3 ) ) <<
                                     "$slice" << -2.1 <<
                                     "$sort" << BSON( "a" << 1 ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
-            BSONObj result = client().findOne( ns(), Query() );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
+            BSONObj result = _client.findOne( ns(), Query() );
             ASSERT_EQUALS( result, expected );
         }
     };
@@ -1524,14 +1524,14 @@ namespace UpdateTests {
     class PushSortValidSortDouble : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,x:[{a:1},{a:2}]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,x:[{a:1},{a:2}]}" ) );
             // { $push : { x : { $each : [ {a:3} ], $slice:-2.0, $sort : {a:1} } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( BSON( "a" << 3 ) ) <<
                                     "$slice" << -2.0 <<
                                     "$sort" << BSON( "a" << 1 ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
             BSONObj expected = fromjson( "{'_id':0,x:[{a:2},{a:3}]}" );
-            BSONObj result = client().findOne( ns(), Query() );
+            BSONObj result = _client.findOne( ns(), Query() );
             ASSERT_EQUALS( result, expected );
         }
     };
@@ -1540,13 +1540,13 @@ namespace UpdateTests {
     public:
         void run() {
             BSONObj expected = fromjson( "{'_id':0,x:[{a:1},{a:2}]}" );
-            client().insert( ns(), expected );
+            _client.insert( ns(), expected );
             // { $push : { x : { $each : [ {a:3} ], $slice:-2.0, $sort : [2, 1] } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( BSON( "a" << 3 ) ) <<
                                     "$slice" << -2.0 <<
                                     "$sort" << BSON_ARRAY( 2 << 1 ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
-            BSONObj result = client().findOne( ns(), Query() );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
+            BSONObj result = _client.findOne( ns(), Query() );
             ASSERT_EQUALS( result, expected );
         }
     };
@@ -1555,13 +1555,13 @@ namespace UpdateTests {
     public:
         void run() {
             BSONObj expected = fromjson( "{'_id':0,x:[{a:1},{a:2}]}" );
-            client().insert( ns(), expected );
+            _client.insert( ns(), expected );
             // { $push : { x : { $each : [ {a:3} ], $slice:-2, $sort : {a:10} } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( BSON( "a" << 3 ) ) <<
                                     "$slice" << -2 <<
                                     "$sort" << BSON( "a" << 10 ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
-            BSONObj result = client().findOne( ns(), Query() );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
+            BSONObj result = _client.findOne( ns(), Query() );
             ASSERT_EQUALS( result, expected );
         }
     };
@@ -1569,14 +1569,14 @@ namespace UpdateTests {
     class PushSortInvertedSortAndSlice : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,x:[{a:1},{a:3}]}" ) );
+            _client.insert( ns(), fromjson( "{'_id':0,x:[{a:1},{a:3}]}" ) );
             // { $push : { x : { $each : [ {a:2} ], $sort: {a:1}, $slice:-2 } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( BSON( "a" << 2 ) ) <<
                                     "$sort" << BSON( "a" << 1 ) <<
                                     "$slice" << -2.0 );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
             BSONObj expected = fromjson( "{'_id':0,x:[{a:2},{a:3}]}" );
-            BSONObj result = client().findOne( ns(), Query() );
+            BSONObj result = _client.findOne( ns(), Query() );
             ASSERT_EQUALS( result, expected );
 
         }
@@ -1586,13 +1586,13 @@ namespace UpdateTests {
     public:
         void run() {
             BSONObj expected = fromjson( "{'_id':0,x:[{a:1},{a:3}]}" );
-            client().insert( ns(), expected );
+            _client.insert( ns(), expected );
             // { $push : { x : { $each : [ {a:2} ], $sort : {a:1}, $sort: {a:1} } } }
             BSONObj pushObj = BSON( "$each" << BSON_ARRAY( BSON( "a" << 2 ) ) <<
                                     "$sort" << BSON( "a" << 1 ) <<
                                     "$sort" << BSON( "a" << 1 ) );
-            client().update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
-            BSONObj result = client().findOne( ns(), Query() );
+            _client.update( ns(), Query(), BSON( "$push" << BSON( "x" << pushObj ) ) );
+            BSONObj result = _client.findOne( ns(), Query() );
             ASSERT_EQUALS( result, expected );
 
         }
@@ -1601,54 +1601,54 @@ namespace UpdateTests {
     class CantIncParent : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:{b:4}}" ) );
-            client().update( ns(), Query(), BSON( "$inc" << BSON( "a" << 4.0 ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{b:4}}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0,a:{b:4}}" ) );
+            _client.update( ns(), Query(), BSON( "$inc" << BSON( "a" << 4.0 ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{b:4}}" ) ) == 0 );
         }
     };
 
     class DontDropEmpty : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:{b:{}}}" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a.c" << 4.0 ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{b:{},c:4}}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0,a:{b:{}}}" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a.c" << 4.0 ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{b:{},c:4}}" ) ) == 0 );
         }
     };
 
     class InsertInEmpty : public SetBase {
     public:
         void run() {
-            client().insert( ns(), fromjson( "{'_id':0,a:{b:{}}}" ) );
-            client().update( ns(), Query(), BSON( "$set" << BSON( "a.b.f" << 4.0 ) ) );
-            ASSERT( client().findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{b:{f:4}}}" ) ) == 0 );
+            _client.insert( ns(), fromjson( "{'_id':0,a:{b:{}}}" ) );
+            _client.update( ns(), Query(), BSON( "$set" << BSON( "a.b.f" << 4.0 ) ) );
+            ASSERT( _client.findOne( ns(), Query() ).woCompare( fromjson( "{'_id':0,a:{b:{f:4}}}" ) ) == 0 );
         }
     };
 
     class IndexParentOfMod : public SetBase {
     public:
         void run() {
-            client().ensureIndex( ns(), BSON( "a" << 1 ) );
-            client().insert( ns(), fromjson( "{'_id':0}" ) );
-            client().update( ns(), Query(), fromjson( "{$set:{'a.b':4}}" ) );
-            ASSERT_EQUALS( fromjson( "{'_id':0,a:{b:4}}" ) , client().findOne( ns(), Query() ) );
-            ASSERT_EQUALS( fromjson( "{'_id':0,a:{b:4}}" ) , client().findOne( ns(), fromjson( "{'a.b':4}" ) ) ); // make sure the index works
+            _client.ensureIndex( ns(), BSON( "a" << 1 ) );
+            _client.insert( ns(), fromjson( "{'_id':0}" ) );
+            _client.update( ns(), Query(), fromjson( "{$set:{'a.b':4}}" ) );
+            ASSERT_EQUALS( fromjson( "{'_id':0,a:{b:4}}" ) , _client.findOne( ns(), Query() ) );
+            ASSERT_EQUALS( fromjson( "{'_id':0,a:{b:4}}" ) , _client.findOne( ns(), fromjson( "{'a.b':4}" ) ) ); // make sure the index works
         }
     };
 
     class PreserveIdWithIndex : public SetBase { // Not using $set, but base class is still useful
     public:
         void run() {
-            client().insert( ns(), BSON( "_id" << 55 << "i" << 5 ) );
-            client().update( ns(), BSON( "i" << 5 ), BSON( "i" << 6 ) );
-            ASSERT( !client().findOne( ns(), Query( BSON( "_id" << 55 ) ).hint ( "{\"_id\":1}" ) ).isEmpty() );
+            _client.insert( ns(), BSON( "_id" << 55 << "i" << 5 ) );
+            _client.update( ns(), BSON( "i" << 5 ), BSON( "i" << 6 ) );
+            ASSERT( !_client.findOne( ns(), Query( BSON( "_id" << 55 ) ).hint ( "{\"_id\":1}" ) ).isEmpty() );
         }
     };
 
     class CheckNoMods : public SetBase {
     public:
         void run() {
-            client().update( ns(), BSONObj(), BSON( "i" << 5 << "$set" << BSON( "q" << 3 ) ), true );
+            _client.update( ns(), BSONObj(), BSON( "i" << 5 << "$set" << BSON( "q" << 3 ) ), true );
             ASSERT( error() );
         }
     };
@@ -1656,9 +1656,9 @@ namespace UpdateTests {
     class UpdateMissingToNull : public SetBase {
     public:
         void run() {
-            client().insert( ns(), BSON( "a" << 5 ) );
-            client().update( ns(), BSON( "a" << 5 ), fromjson( "{$set:{b:null}}" ) );
-            ASSERT_EQUALS( jstNULL, client().findOne( ns(), QUERY( "a" << 5 ) ).getField( "b" ).type() );
+            _client.insert( ns(), BSON( "a" << 5 ) );
+            _client.update( ns(), BSON( "a" << 5 ), fromjson( "{$set:{b:null}}" ) );
+            ASSERT_EQUALS( jstNULL, _client.findOne( ns(), QUERY( "a" << 5 ) ).getField( "b" ).type() );
         }
     };
 
@@ -1666,14 +1666,14 @@ namespace UpdateTests {
     class TwoModsWithinDuplicatedField : public SetBase {
     public:
         void run() {
-            client().insert( ns(), BSON( "_id" << 0 << "a" << 1
+            _client.insert( ns(), BSON( "_id" << 0 << "a" << 1
                                         << "x" << BSONObj() << "x" << BSONObj()
                                         << "z" << 5 ) );
-            client().update( ns(), BSONObj(), BSON( "$set" << BSON( "x.b" << 1 << "x.c" << 1 ) ) );
+            _client.update( ns(), BSONObj(), BSON( "$set" << BSON( "x.b" << 1 << "x.c" << 1 ) ) );
             ASSERT_EQUALS( BSON( "_id" << 0 << "a" << 1
                                 << "x" << BSON( "b" << 1 << "c" << 1 ) << "x" << BSONObj()
                                 << "z" << 5 ),
-                          client().findOne( ns(), BSONObj() ) );
+                          _client.findOne( ns(), BSONObj() ) );
         }
     };
 
@@ -1681,27 +1681,27 @@ namespace UpdateTests {
     class ThreeModsWithinDuplicatedField : public SetBase {
     public:
         void run() {
-            client().insert( ns(),
+            _client.insert( ns(),
                             BSON( "_id" << 0
                                  << "x" << BSONObj() << "x" << BSONObj() << "x" << BSONObj() ) );
-            client().update( ns(), BSONObj(),
+            _client.update( ns(), BSONObj(),
                             BSON( "$set" << BSON( "x.b" << 1 << "x.c" << 1 << "x.d" << 1 ) ) );
             ASSERT_EQUALS( BSON( "_id" << 0
                                 << "x" << BSON( "b" << 1 << "c" << 1 << "d" << 1 )
                                 << "x" << BSONObj() << "x" << BSONObj() ),
-                          client().findOne( ns(), BSONObj() ) );
+                          _client.findOne( ns(), BSONObj() ) );
         }
     };
 
     class TwoModsBeforeExistingField : public SetBase {
     public:
         void run() {
-            client().insert( ns(), BSON( "_id" << 0 << "x" << 5 ) );
-            client().update( ns(), BSONObj(),
+            _client.insert( ns(), BSON( "_id" << 0 << "x" << 5 ) );
+            _client.update( ns(), BSONObj(),
                             BSON( "$set" << BSON( "a" << 1 << "b" << 1 << "x" << 10 ) ) );
             ASSERT_EQUALS(
                 mutablebson::unordered( BSON( "_id" << 0 << "a" << 1 << "b" << 1 << "x" << 10 ) ),
-                mutablebson::unordered( client().findOne( ns(), BSONObj() ) ) );
+                mutablebson::unordered( _client.findOne( ns(), BSONObj() ) ) );
         }
     };
 
@@ -1713,15 +1713,15 @@ namespace UpdateTests {
             virtual void dotest() = 0;
 
             void insert( const BSONObj& o ) {
-                client().insert( ns() , o );
+                _client.insert( ns() , o );
             }
 
             void update( const BSONObj& m ) {
-                client().update( ns() , BSONObj() , m );
+                _client.update( ns() , BSONObj() , m );
             }
 
             BSONObj findOne() {
-                return client().findOne( ns() , BSONObj() );
+                return _client.findOne( ns() , BSONObj() );
             }
 
             void test( const char* initial , const char* mod , const char* after ) {
@@ -1730,11 +1730,11 @@ namespace UpdateTests {
 
 
             void test( const BSONObj& initial , const BSONObj& mod , const BSONObj& after ) {
-                client().dropCollection( ns() );
+                _client.dropCollection( ns() );
                 insert( initial );
                 update( mod );
                 ASSERT_EQUALS( after , findOne() );
-                client().dropCollection( ns() );
+                _client.dropCollection( ns() );
             }
 
         public:
@@ -1744,11 +1744,11 @@ namespace UpdateTests {
             }
 
             void run() {
-                client().dropCollection( ns() );
+                _client.dropCollection( ns() );
 
                 dotest();
 
-                client().dropCollection( ns() );
+                _client.dropCollection( ns() );
             }
         };
 
@@ -1858,7 +1858,7 @@ namespace UpdateTests {
                 long long start = numeric_limits<int>::max() - 5;
                 long long max   = numeric_limits<int>::max() + 5ll;
 
-                client().insert( ns() , BSON( "x" << (int)start ) );
+                _client.insert( ns() , BSON( "x" << (int)start ) );
                 ASSERT( findOne()["x"].type() == NumberInt );
 
                 while ( start < max ) {
diff --git a/src/mongo/s/d_migrate.cpp b/src/mongo/s/d_migrate.cpp
index 6ca6b19ca57..47facbfc02a 100644
--- a/src/mongo/s/d_migrate.cpp
+++ b/src/mongo/s/d_migrate.cpp
@@ -308,7 +308,7 @@ namespace mongo {
                 break;
 
             case 'u':
-                Client::Context ctx( _ns );
+                Client::Context ctx(txn,  _ns );
                 if ( ! Helpers::findById( txn, ctx.db(), _ns.c_str(), ide.wrap(), it ) ) {
                     warning() << "logOpForSharding couldn't find: " << ide << " even though should have" << migrateLog;
                     return;
diff --git a/src/mongo/s/d_state.cpp b/src/mongo/s/d_state.cpp
index 80d0a9eda96..767e894ab58 100644
--- a/src/mongo/s/d_state.cpp
+++ b/src/mongo/s/d_state.cpp
@@ -1247,7 +1247,7 @@ namespace mongo {
 
         bool run(OperationContext* txn, const string& dbname, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool) {
             Lock::DBWrite dbXLock(txn->lockState(), dbname);
-            Client::Context ctx(dbname);
+            Client::Context ctx(txn, dbname);
 
             shardingState.appendInfo( result );
             return true;