SERVER-18122 Move sharding global settings retrieval to the catalog manager

Also moved type_settings* to src/mongo/s/catalog/

18 files changed, 83 insertions, 101 deletions

diff --git a/jstests/sharding/fair_balancer_round.js b/jstests/sharding/fair_balancer_round.js
index d78f4ca2efd..a565b469667 100644
--- a/jstests/sharding/fair_balancer_round.js
+++ b/jstests/sharding/fair_balancer_round.js
@@ -9,13 +9,10 @@ var st = new ShardingTest({shards : 2, mongos : 2, other : options});
 // Stop balancer initially
 st.stopBalancer();
 
-var mongos = st.s0;
-var staleMongos = st.s1;
+var staleMongos = st.s0;
+var mongos = st.s1;
 var coll = mongos.getCollection("foo.bar");
 
-// Stop first mongos from balancing
-assert(mongos.adminCommand({configureFailPoint : "neverBalance", mode : "alwaysOn"}).ok);
-
 // Shard collection through first mongos
 assert(mongos.adminCommand({enableSharding : coll.getDB() + ""}).ok);
 assert(mongos.adminCommand({shardCollection : coll + "", key : {_id : 1}}).ok);
@@ -26,12 +23,15 @@ for ( var i = 0; i < numSplits; i++) {
     assert(mongos.adminCommand({split : coll + "", middle : {_id : i}}).ok);
 }
 
+// stop st.s1
+st.stopMongos(1);
+
 // Start balancer, which lets the stale mongos balance
 st.startBalancer();
 
 // Make sure we eventually start moving chunks
 assert.soon(function() {
-    return mongos.getCollection("config.changelog").count({what : /moveChunk/}) > 0;
+    return staleMongos.getCollection("config.changelog").count({what : /moveChunk/}) > 0;
 }, "no balance happened", 5 * 60 * 1000);
 
 jsTest.log("DONE!");
diff --git a/src/mongo/db/commands/cleanup_orphaned_cmd.cpp b/src/mongo/db/commands/cleanup_orphaned_cmd.cpp
index 876297e2d56..89f57103958 100644
--- a/src/mongo/db/commands/cleanup_orphaned_cmd.cpp
+++ b/src/mongo/db/commands/cleanup_orphaned_cmd.cpp
@@ -47,7 +47,6 @@
 #include "mongo/db/repl/replication_coordinator_global.h"
 #include "mongo/s/collection_metadata.h"
 #include "mongo/s/d_state.h"
-#include "mongo/s/type_settings.h"
 #include "mongo/util/log.h"
 
 namespace {
diff --git a/src/mongo/dbtests/config_upgrade_tests.cpp b/src/mongo/dbtests/config_upgrade_tests.cpp
index b500c082dbe..17ad4a25331 100644
--- a/src/mongo/dbtests/config_upgrade_tests.cpp
+++ b/src/mongo/dbtests/config_upgrade_tests.cpp
@@ -30,10 +30,10 @@
 #include "mongo/s/catalog/legacy/cluster_client_internal.h"
 #include "mongo/s/catalog/legacy/config_upgrade.h"
 #include "mongo/s/catalog/type_chunk.h"
+#include "mongo/s/catalog/type_settings.h"
 #include "mongo/s/catalog/type_shard.h"
 #include "mongo/s/chunk_version.h"
 #include "mongo/s/type_mongos.h"
-#include "mongo/s/type_settings.h"
 #include "mongo/s/type_config_version.h"
 #include "mongo/unittest/unittest.h"
 #include "mongo/util/version.h"
diff --git a/src/mongo/s/SConscript b/src/mongo/s/SConscript
index 06018a72e22..74bd0e54fc7 100644
--- a/src/mongo/s/SConscript
+++ b/src/mongo/s/SConscript
@@ -10,7 +10,6 @@ env.Library('base', ['mongo_version_range.cpp',
                      'type_database.cpp',
                      'type_locks.cpp',
                      'type_lockpings.cpp',
-                     'type_settings.cpp',
                      'type_config_version.cpp',
                      'type_mongos.cpp',
                      'type_tags.cpp'],
@@ -42,10 +41,6 @@ env.CppUnitTest('type_lockpings_test', 'type_lockpings_test.cpp',
                 LIBDEPS=['base',
                          '$BUILD_DIR/mongo/db/common'])
 
-env.CppUnitTest('type_settings_test', 'type_settings_test.cpp',
-                LIBDEPS=['base',
-                         '$BUILD_DIR/mongo/db/common'])
-
 env.CppUnitTest('type_mongos_test', 'type_mongos_test.cpp',
                 LIBDEPS=['base',
                          '$BUILD_DIR/mongo/db/common'])
diff --git a/src/mongo/s/balance.cpp b/src/mongo/s/balance.cpp
index f4970f872bd..8e384939c25 100644
--- a/src/mongo/s/balance.cpp
+++ b/src/mongo/s/balance.cpp
@@ -46,6 +46,7 @@
 #include "mongo/s/catalog/type_actionlog.h"
 #include "mongo/s/catalog/type_chunk.h"
 #include "mongo/s/catalog/type_collection.h"
+#include "mongo/s/catalog/type_settings.h"
 #include "mongo/s/chunk_manager.h"
 #include "mongo/s/config.h"
 #include "mongo/s/config_server_checker_service.h"
@@ -54,7 +55,6 @@
 #include "mongo/s/server.h"
 #include "mongo/s/client/shard.h"
 #include "mongo/s/type_mongos.h"
-#include "mongo/s/type_settings.h"
 #include "mongo/s/type_tags.h"
 #include "mongo/util/exit.h"
 #include "mongo/util/fail_point_service.h"
@@ -97,14 +97,13 @@ namespace mongo {
 
             // If the balancer was disabled since we started this round, don't start new
             // chunks moves.
-            SettingsType balancerConfig;
-            std::string errMsg;
-
-            if (!grid.getBalancerSettings(&balancerConfig, &errMsg)) {
-                warning() << errMsg;
-                // No point in continuing the round if the config servers are unreachable.
+            auto balSettingsResult =
+                grid.catalogManager()->getGlobalSettings(SettingsType::BalancerDocKey);
+            if (!balSettingsResult.isOK()) {
+                warning() << balSettingsResult.getStatus();
                 return movedCount;
             }
+            const SettingsType& balancerConfig = balSettingsResult.getValue();
 
             if ((balancerConfig.isKeySet() && // balancer config doc exists
                     !grid.shouldBalance(balancerConfig)) ||
@@ -538,13 +537,13 @@ namespace mongo {
                 // refresh chunk size (even though another balancer might be active)
                 Chunk::refreshChunkSize();
 
-                SettingsType balancerConfig;
-                string errMsg;
-
-                if (!grid.getBalancerSettings(&balancerConfig, &errMsg)) {
-                    warning() << errMsg;
-                    return ;
+                auto balSettingsResult =
+                    grid.catalogManager()->getGlobalSettings(SettingsType::BalancerDocKey);
+                if (!balSettingsResult.isOK()) {
+                    warning() << balSettingsResult.getStatus();
+                    return;
                 }
+                const SettingsType& balancerConfig = balSettingsResult.getValue();
 
                 // now make sure we should even be running
                 if ((balancerConfig.isKeySet() && // balancer config doc exists
diff --git a/src/mongo/s/balancing_window_test.cpp b/src/mongo/s/balancing_window_test.cpp
index c24fe283318..f2390a6527a 100644
--- a/src/mongo/s/balancing_window_test.cpp
+++ b/src/mongo/s/balancing_window_test.cpp
@@ -27,8 +27,8 @@
 
 #define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kDefault
 
+#include "mongo/s/catalog/type_settings.h"
 #include "mongo/s/grid.h"
-#include "mongo/s/type_settings.h"
 #include "mongo/unittest/unittest.h"
 #include "mongo/util/log.h"
 
diff --git a/src/mongo/s/catalog/SConscript b/src/mongo/s/catalog/SConscript
index c0b21710cef..f8ae4049b1b 100644
--- a/src/mongo/s/catalog/SConscript
+++ b/src/mongo/s/catalog/SConscript
@@ -9,6 +9,7 @@ env.Library(
         'type_changelog.cpp',
         'type_chunk.cpp',
         'type_collection.cpp',
+        'type_settings.cpp',
         'type_shard.cpp'
     ],
     LIBDEPS=[
@@ -39,6 +40,7 @@ env.CppUnitTest(
         'type_changelog_test.cpp',
         'type_chunk_test.cpp',
         'type_collection_test.cpp',
+        'type_settings_test.cpp',
         'type_shard_test.cpp'
     ],
     LIBDEPS=[
diff --git a/src/mongo/s/catalog/catalog_manager.h b/src/mongo/s/catalog/catalog_manager.h
index 291f174ba16..b6af95df830 100644
--- a/src/mongo/s/catalog/catalog_manager.h
+++ b/src/mongo/s/catalog/catalog_manager.h
@@ -46,6 +46,7 @@ namespace mongo {
     class ConnectionString;
     class DatabaseType;
     class OperationContext;
+    class SettingsType;
     class Shard;
     class ShardKeyPattern;
     class ShardType;
@@ -267,6 +268,16 @@ namespace mongo {
                                const BSONObj& detail) = 0;
 
         /**
+         * Returns global settings for a certain key.
+         * @param key: key for SettingsType::ConfigNS document.
+         *
+         * NOTE: If no document with such a key exists, an empty SettingsType object will
+         *       will be returned. It is up to the caller to check if the SettingsType
+         *       is non-empty (via the keySet() method on the SettingsType).
+         */
+        virtual StatusWith<SettingsType> getGlobalSettings(const std::string& key) = 0;
+
+        /**
          * Directly sends the specified command to the config server and returns the response.
          *
          * NOTE: Usage of this function is disallowed in new code, which should instead go through
diff --git a/src/mongo/s/catalog/legacy/catalog_manager_legacy.cpp b/src/mongo/s/catalog/legacy/catalog_manager_legacy.cpp
index bb9cc4007ae..d296ff151ba 100644
--- a/src/mongo/s/catalog/legacy/catalog_manager_legacy.cpp
+++ b/src/mongo/s/catalog/legacy/catalog_manager_legacy.cpp
@@ -50,6 +50,7 @@
 #include "mongo/s/catalog/type_changelog.h"
 #include "mongo/s/catalog/type_chunk.h"
 #include "mongo/s/catalog/type_collection.h"
+#include "mongo/s/catalog/type_settings.h"
 #include "mongo/s/catalog/type_shard.h"
 #include "mongo/s/chunk_manager.h"
 #include "mongo/s/client/dbclient_multi_command.h"
@@ -1048,6 +1049,32 @@ namespace {
         }
     }
 
+    StatusWith<SettingsType> CatalogManagerLegacy::getGlobalSettings(const string& key) {
+        SettingsType settingsType;
+
+        try {
+            ScopedDbConnection conn(_configServerConnectionString, 30);
+            BSONObj settingsDoc = conn->findOne(SettingsType::ConfigNS,
+                                                BSON(SettingsType::key(key)));
+
+            string errMsg;
+            if (!settingsType.parseBSON(settingsDoc, &errMsg)) {
+                conn.done();
+                return Status(ErrorCodes::UnsupportedFormat,
+                              str::stream() << "error parsing config.settings document: "
+                                            << errMsg);
+            }
+            conn.done();
+        }
+        catch (const DBException& ex) {
+            return Status(ErrorCodes::OperationFailed,
+                          str::stream() << "unable to successfully obtain config.settings document: "
+                                        << causedBy(ex));
+        }
+
+        return settingsType;
+    }
+
     void CatalogManagerLegacy::getDatabasesForShard(const string& shardName,
                                                     vector<string>* dbs) {
         ScopedDbConnection conn(_configServerConnectionString, 30.0);
diff --git a/src/mongo/s/catalog/legacy/catalog_manager_legacy.h b/src/mongo/s/catalog/legacy/catalog_manager_legacy.h
index f0ff435e606..8f334d8b7e0 100644
--- a/src/mongo/s/catalog/legacy/catalog_manager_legacy.h
+++ b/src/mongo/s/catalog/legacy/catalog_manager_legacy.h
@@ -103,6 +103,8 @@ namespace mongo {
                                const std::string& ns,
                                const BSONObj& detail);
 
+        virtual StatusWith<SettingsType> getGlobalSettings(const std::string& key);
+
         virtual void writeConfigServerDirect(const BatchedCommandRequest& request,
                                              BatchedCommandResponse* response);
 
diff --git a/src/mongo/s/catalog/legacy/config_upgrade.cpp b/src/mongo/s/catalog/legacy/config_upgrade.cpp
index 6ce128d2764..3fa62946e42 100644
--- a/src/mongo/s/catalog/legacy/config_upgrade.cpp
+++ b/src/mongo/s/catalog/legacy/config_upgrade.cpp
@@ -37,13 +37,13 @@
 #include "mongo/s/catalog/catalog_manager.h"
 #include "mongo/s/catalog/legacy/cluster_client_internal.h"
 #include "mongo/s/catalog/type_collection.h"
+#include "mongo/s/catalog/type_settings.h"
 #include "mongo/s/catalog/type_shard.h"
 #include "mongo/s/distlock.h"
 #include "mongo/s/grid.h"
 #include "mongo/s/mongo_version_range.h"
 #include "mongo/s/type_config_version.h"
 #include "mongo/s/type_database.h"
-#include "mongo/s/type_settings.h"
 #include "mongo/stdx/functional.h"
 #include "mongo/util/assert_util.h"
 #include "mongo/util/log.h"
diff --git a/src/mongo/s/type_settings.cpp b/src/mongo/s/catalog/type_settings.cpp
index dc6f0deca50..1544c9ce056 100644
--- a/src/mongo/s/type_settings.cpp
+++ b/src/mongo/s/catalog/type_settings.cpp
@@ -25,7 +25,7 @@
  *    delete this exception statement from all source files in the program,
  *    then also delete it in the license file.
  */
-#include "mongo/s/type_settings.h"
+#include "mongo/s/catalog/type_settings.h"
 
 #include "mongo/db/field_parser.h"
 #include "mongo/db/write_concern_options.h"
diff --git a/src/mongo/s/type_settings.h b/src/mongo/s/catalog/type_settings.h
index 9d6cbe26b5b..11bd68c584e 100644
--- a/src/mongo/s/type_settings.h
+++ b/src/mongo/s/catalog/type_settings.h
@@ -65,7 +65,6 @@ namespace mongo {
      * balancer settings or chunk size settings document).
      */
     class SettingsType {
-        MONGO_DISALLOW_COPYING(SettingsType);
     public:
 
         //
diff --git a/src/mongo/s/type_settings_test.cpp b/src/mongo/s/catalog/type_settings_test.cpp
index 651c53d056c..ca8755b6baf 100644
--- a/src/mongo/s/type_settings_test.cpp
+++ b/src/mongo/s/catalog/type_settings_test.cpp
@@ -26,7 +26,7 @@
  *    then also delete it in the license file.
  */
 
-#include "mongo/s/type_settings.h"
+#include "mongo/s/catalog/type_settings.h"
 #include "mongo/unittest/unittest.h"
 
 namespace {
diff --git a/src/mongo/s/chunk.cpp b/src/mongo/s/chunk.cpp
index dcdd528a548..b62a0da7512 100644
--- a/src/mongo/s/chunk.cpp
+++ b/src/mongo/s/chunk.cpp
@@ -46,12 +46,12 @@
 #include "mongo/s/balancer_policy.h"
 #include "mongo/s/catalog/catalog_manager.h"
 #include "mongo/s/catalog/type_collection.h"
+#include "mongo/s/catalog/type_settings.h"
 #include "mongo/s/chunk_manager.h"
 #include "mongo/s/config.h"
 #include "mongo/s/config_server_checker_service.h"
 #include "mongo/s/cursors.h"
 #include "mongo/s/grid.h"
-#include "mongo/s/type_settings.h"
 #include "mongo/util/concurrency/ticketholder.h"
 #include "mongo/util/log.h"
 
@@ -730,20 +730,19 @@ namespace {
     }
 
     void Chunk::refreshChunkSize() {
-        BSONObj o = grid.getConfigSetting("chunksize");
-
-        if ( o.isEmpty() ) {
-           return;
+        auto chunkSizeSettingsResult =
+            grid.catalogManager()->getGlobalSettings(SettingsType::ChunkSizeDocKey);
+        if (!chunkSizeSettingsResult.isOK()) {
+            log() << chunkSizeSettingsResult.getStatus();
+            return;
         }
-
-        int csize = o[SettingsType::chunksize()].numberInt();
-
-        // validate chunksize before proceeding
-        if ( csize == 0 ) {
-            // setting was not modified; mark as such
-            log() << "warning: invalid chunksize (" << csize << ") ignored";
+        SettingsType chunkSizeSettings = chunkSizeSettingsResult.getValue();
+        string errMsg;
+        if (!chunkSizeSettings.isValid(&errMsg)) {
+            log() << errMsg;
             return;
         }
+        int csize = chunkSizeSettings.getChunksize();
 
         LOG(1) << "Refreshing MaxChunkSize: " << csize << "MB";
 
diff --git a/src/mongo/s/config.cpp b/src/mongo/s/config.cpp
index f8e08ba12fa..e8dd8e60d44 100644
--- a/src/mongo/s/config.cpp
+++ b/src/mongo/s/config.cpp
@@ -45,6 +45,7 @@
 #include "mongo/s/catalog/catalog_manager.h"
 #include "mongo/s/catalog/type_collection.h"
 #include "mongo/s/catalog/type_chunk.h"
+#include "mongo/s/catalog/type_settings.h"
 #include "mongo/s/catalog/type_shard.h"
 #include "mongo/s/chunk_manager.h"
 #include "mongo/s/chunk_version.h"
@@ -55,7 +56,6 @@
 #include "mongo/s/type_database.h"
 #include "mongo/s/type_locks.h"
 #include "mongo/s/type_lockpings.h"
-#include "mongo/s/type_settings.h"
 #include "mongo/s/type_tags.h"
 #include "mongo/util/exit.h"
 #include "mongo/util/log.h"
diff --git a/src/mongo/s/grid.cpp b/src/mongo/s/grid.cpp
index 5cce580cc76..a9860fda1fa 100644
--- a/src/mongo/s/grid.cpp
+++ b/src/mongo/s/grid.cpp
@@ -36,9 +36,9 @@
 #include "mongo/client/connpool.h"
 #include "mongo/s/catalog/catalog_cache.h"
 #include "mongo/s/catalog/catalog_manager.h"
+#include "mongo/s/catalog/type_settings.h"
 #include "mongo/s/catalog/type_shard.h"
 #include "mongo/s/config.h"
-#include "mongo/s/type_settings.h"
 #include "mongo/util/fail_point_service.h"
 #include "mongo/util/log.h"
 
@@ -51,9 +51,6 @@ namespace mongo {
     using std::string;
     using std::vector;
 
-    MONGO_FP_DECLARE(neverBalance);
-
-
     Grid::Grid() : _allowLocalShard(true) {
 
     }
@@ -96,11 +93,7 @@ namespace mongo {
      * Returns whether balancing is enabled, with optional namespace "ns" parameter for balancing on a particular
      * collection.
      */
-
     bool Grid::shouldBalance(const SettingsType& balancerSettings) const {
-        // Allow disabling the balancer for testing
-        if (MONGO_FAIL_POINT(neverBalance)) return false;
-
         if (balancerSettings.isBalancerStoppedSet() && balancerSettings.getBalancerStopped()) {
             return false;
         }
@@ -113,32 +106,14 @@ namespace mongo {
         return true;
     }
 
-    bool Grid::getBalancerSettings(SettingsType* settings, string* errMsg) const {
-        BSONObj balancerDoc;
-        ScopedDbConnection conn(configServer.getPrimary().getConnString(), 30);
-
-        try {
-            balancerDoc = conn->findOne(SettingsType::ConfigNS,
-                                        BSON(SettingsType::key("balancer")));
-            conn.done();
-        }
-        catch (const DBException& ex) {
-            *errMsg = str::stream() << "failed to read balancer settings from " << conn.getHost()
-                                    << ": " << causedBy(ex);
-            return false;
-        }
-
-        return settings->parseBSON(balancerDoc, errMsg);
-    }
-
     bool Grid::getConfigShouldBalance() const {
-        SettingsType balSettings;
-        string errMsg;
-
-        if (!getBalancerSettings(&balSettings, &errMsg)) {
-            warning() << errMsg;
+        auto balSettingsResult =
+            grid.catalogManager()->getGlobalSettings(SettingsType::BalancerDocKey);
+        if (!balSettingsResult.isOK()) {
+            warning() << balSettingsResult.getStatus();
             return false;
         }
+        SettingsType balSettings = balSettingsResult.getValue();
 
         if (!balSettings.isKeySet()) {
             // Balancer settings doc does not exist. Default to yes.
@@ -198,14 +173,5 @@ namespace mongo {
         return false;
     }
 
-    BSONObj Grid::getConfigSetting( const std::string& name ) const {
-        ScopedDbConnection conn(configServer.getPrimary().getConnString(), 30);
-        BSONObj result = conn->findOne( SettingsType::ConfigNS,
-                                        BSON( SettingsType::key(name) ) );
-        conn.done();
-
-        return result;
-    }
-
     Grid grid;
 }
diff --git a/src/mongo/s/grid.h b/src/mongo/s/grid.h
index 21b4be76fc9..d70db0ac01d 100644
--- a/src/mongo/s/grid.h
+++ b/src/mongo/s/grid.h
@@ -81,14 +81,6 @@ namespace mongo {
         bool shouldBalance(const SettingsType& balancerSettings) const;
 
         /**
-         * Retrieve the balancer settings from the config server. Returns false if an error
-         * occurred while retrieving the document. If the balancer settings document does not
-         * exist, it is not considered as an error, but the "key" property of the settings
-         * output parameter will not be set.
-         */
-        bool getBalancerSettings(SettingsType* settings, std::string* errMsg) const;
-
-        /**
          * Returns true if the config server settings indicate that the balancer should be active.
          */
         bool getConfigShouldBalance() const;
@@ -96,15 +88,6 @@ namespace mongo {
         CatalogManager* catalogManager() const { return _catalogManager.get(); }
         CatalogCache* catalogCache() const { return _catalogCache.get(); }
 
-        /**
-         * 
-         * Obtain grid configuration and settings data.
-         *
-         * @param name identifies a particular type of configuration data.
-         * @return a BSON object containing the requested data.
-         */
-        BSONObj getConfigSetting( const std::string& name ) const;
-
         // exposed methods below are for testing only
 
         /**