Revert "SERVER-19855 Include min OpTime with shard version"

This reverts commit cec89b290906adb7d36507d20d619aaa5a6f6c16.

25 files changed, 301 insertions, 520 deletions

diff --git a/src/mongo/db/repl/optime_pair.h b/src/mongo/db/repl/optime_pair.h
deleted file mode 100644
index 0f301784f7e..00000000000
--- a/src/mongo/db/repl/optime_pair.h
+++ /dev/null
@@ -1,48 +0,0 @@
-/**
- *    Copyright (C) 2015 MongoDB Inc.
- *
- *    This program is free software: you can redistribute it and/or  modify
- *    it under the terms of the GNU Affero General Public License, version 3,
- *    as published by the Free Software Foundation.
- *
- *    This program is distributed in the hope that it will be useful,
- *    but WITHOUT ANY WARRANTY; without even the implied warranty of
- *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *    GNU Affero General Public License for more details.
- *
- *    You should have received a copy of the GNU Affero General Public License
- *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- *    As a special exception, the copyright holders give permission to link the
- *    code of portions of this program with the OpenSSL library under certain
- *    conditions as described in each individual source file and distribute
- *    linked combinations including the program with the OpenSSL library. You
- *    must comply with the GNU Affero General Public License in all respects for
- *    all of the code used other than as permitted herein. If you modify file(s)
- *    with this exception, you may extend this exception to your version of the
- *    file(s), but you are not obligated to do so. If you do not wish to do so,
- *    delete this exception statement from your version. If you delete this
- *    exception statement from all source files in the program, then also delete
- *    it in the license file.
- */
-
-#pragma once
-
-#include "mongo/db/repl/optime.h"
-
-namespace mongo {
-namespace repl {
-
-template <typename T>
-struct OpTimePair {
-public:
-    OpTimePair() = default;
-    explicit OpTimePair(T val) : value(std::move(val)) {}
-    OpTimePair(T val, OpTime ts) : value(std::move(val)), opTime(std::move(ts)) {}
-
-    T value;
-    OpTime opTime;
-};
-
-}  // namespace repl
-}  // namespace mongo
diff --git a/src/mongo/db/s/set_shard_version_command.cpp b/src/mongo/db/s/set_shard_version_command.cpp
index 03b96373844..f95bc3cef7a 100644
--- a/src/mongo/db/s/set_shard_version_command.cpp
+++ b/src/mongo/db/s/set_shard_version_command.cpp
@@ -149,11 +149,15 @@ public:
         }
 
         // step 2
-        ChunkVersionAndOpTime verAndOpTime =
-            uassertStatusOK(ChunkVersionAndOpTime::parseFromBSONForSetShardVersion(cmdObj));
-        const auto& version = verAndOpTime.getVersion();
+        if (!ChunkVersion::canParseBSON(cmdObj, "version")) {
+            errmsg = "need to specify version";
+            return false;
+        }
+
+        const ChunkVersion version = ChunkVersion::fromBSON(cmdObj, "version");
 
         // step 3
+
         const ChunkVersion oldVersion = info->getVersion(ns);
         const ChunkVersion globalVersion = ShardingState::get(txn)->getVersion(ns);
 
diff --git a/src/mongo/s/SConscript b/src/mongo/s/SConscript
index 72ddfe1549f..df9b3cdef5d 100644
--- a/src/mongo/s/SConscript
+++ b/src/mongo/s/SConscript
@@ -33,13 +33,11 @@ env.Library(
     target='common',
     source=[
         'chunk_diff.cpp',
-        'chunk_version.cpp',
         'set_shard_version_request.cpp',
     ],
     LIBDEPS=[
         'catalog/catalog_types',
         '$BUILD_DIR/mongo/client/connection_string',
-        '$BUILD_DIR/mongo/db/repl/optime',
     ]
 )
 
diff --git a/src/mongo/s/catalog/legacy/catalog_manager_legacy.cpp b/src/mongo/s/catalog/legacy/catalog_manager_legacy.cpp
index 957f799ba44..73d38b1e610 100644
--- a/src/mongo/s/catalog/legacy/catalog_manager_legacy.cpp
+++ b/src/mongo/s/catalog/legacy/catalog_manager_legacy.cpp
@@ -607,7 +607,7 @@ Status CatalogManagerLegacy::dropCollection(OperationContext* txn, const Namespa
             shardEntry.getName(),
             fassertStatusOK(28753, ConnectionString::parse(shardEntry.getHost())),
             ns,
-            ChunkVersionAndOpTime(ChunkVersion::DROPPED()),
+            ChunkVersion::DROPPED(),
             true);
 
         auto ssvResult = shardRegistry->runCommandWithNotMasterRetries(
diff --git a/src/mongo/s/catalog/replset/catalog_manager_replica_set.cpp b/src/mongo/s/catalog/replset/catalog_manager_replica_set.cpp
index bc8ee282ef3..dcc3e2d68e3 100644
--- a/src/mongo/s/catalog/replset/catalog_manager_replica_set.cpp
+++ b/src/mongo/s/catalog/replset/catalog_manager_replica_set.cpp
@@ -212,7 +212,7 @@ Status CatalogManagerReplicaSet::shardCollection(OperationContext* txn,
         dbPrimaryShardId,
         primaryShard->getConnString(),
         NamespaceString(ns),
-        ChunkVersionAndOpTime(manager->getVersion(), manager->getConfigOpTime()),
+        manager->getVersion(),
         true);
 
     auto ssvStatus = grid.shardRegistry()->runCommandWithNotMasterRetries(
@@ -518,18 +518,13 @@ Status CatalogManagerReplicaSet::dropCollection(OperationContext* txn, const Nam
 
     LOG(1) << "dropCollection " << ns << " collection marked as dropped";
 
-    // We just called updateCollection above and this would have advanced the config op time, so use
-    // the latest value. On the MongoD side, we need to load the latest config metadata, which
-    // indicates that the collection was dropped.
-    const ChunkVersionAndOpTime droppedVersion(ChunkVersion::DROPPED(), _getConfigOpTime());
-
     for (const auto& shardEntry : allShards) {
         SetShardVersionRequest ssv = SetShardVersionRequest::makeForVersioningNoPersist(
             grid.shardRegistry()->getConfigServerConnectionString(),
             shardEntry.getName(),
             fassertStatusOK(28781, ConnectionString::parse(shardEntry.getHost())),
             ns,
-            droppedVersion,
+            ChunkVersion::DROPPED(),
             true);
 
         auto ssvResult = shardRegistry->runCommandWithNotMasterRetries(
diff --git a/src/mongo/s/chunk_manager.cpp b/src/mongo/s/chunk_manager.cpp
index 74fabae55a9..638935ddbf5 100644
--- a/src/mongo/s/chunk_manager.cpp
+++ b/src/mongo/s/chunk_manager.cpp
@@ -172,10 +172,6 @@ ChunkManager::ChunkManager(const CollectionType& coll)
     _version = ChunkVersion::fromBSON(coll.toBSON());
 }
 
-repl::OpTime ChunkManager::getConfigOpTime() const {
-    return repl::OpTime(Timestamp(0, 0), 0);
-}
-
 void ChunkManager::loadExistingRanges(OperationContext* txn, const ChunkManager* oldManager) {
     int tries = 3;
 
diff --git a/src/mongo/s/chunk_manager.h b/src/mongo/s/chunk_manager.h
index 23440fced18..0ca94237920 100644
--- a/src/mongo/s/chunk_manager.h
+++ b/src/mongo/s/chunk_manager.h
@@ -44,10 +44,6 @@ class CollectionType;
 struct QuerySolutionNode;
 class OperationContext;
 
-namespace repl {
-class OpTime;
-}
-
 typedef std::shared_ptr<ChunkManager> ChunkManagerPtr;
 
 // The key for the map is max for each Chunk or ChunkRange
@@ -158,11 +154,6 @@ public:
         return _sequenceNumber;
     }
 
-    /**
-     * Returns the latest op time from when this chunk manager's data was loaded.
-     */
-    repl::OpTime getConfigOpTime() const;
-
     //
     // After constructor is invoked, we need to call loadExistingRanges.  If this is a new
     // sharded collection, we can call createFirstChunks first.
diff --git a/src/mongo/s/chunk_manager_targeter.cpp b/src/mongo/s/chunk_manager_targeter.cpp
index a3de1e2235e..f4448dafe5d 100644
--- a/src/mongo/s/chunk_manager_targeter.cpp
+++ b/src/mongo/s/chunk_manager_targeter.cpp
@@ -320,8 +320,7 @@ Status ChunkManagerTargeter::targetInsert(OperationContext* txn,
                                         << "; no metadata found");
         }
 
-        *endpoint =
-            new ShardEndpoint(_primary->getId(), ChunkVersionAndOpTime(ChunkVersion::UNSHARDED()));
+        *endpoint = new ShardEndpoint(_primary->getId(), ChunkVersion::UNSHARDED());
         return Status::OK();
     }
 }
@@ -497,10 +496,7 @@ Status ChunkManagerTargeter::targetQuery(const BSONObj& query,
 
     for (const ShardId& shardId : shardIds) {
         endpoints->push_back(new ShardEndpoint(
-            shardId,
-            _manager
-                ? ChunkVersionAndOpTime(_manager->getVersion(shardId), _manager->getConfigOpTime())
-                : ChunkVersionAndOpTime(ChunkVersion::UNSHARDED())));
+            shardId, _manager ? _manager->getVersion(shardId) : ChunkVersion::UNSHARDED()));
     }
 
     return Status::OK();
@@ -520,9 +516,7 @@ Status ChunkManagerTargeter::targetShardKey(OperationContext* txn,
         _stats.chunkSizeDelta[chunk->getMin()] += estDataSize;
     }
 
-    *endpoint = new ShardEndpoint(chunk->getShardId(),
-                                  ChunkVersionAndOpTime(_manager->getVersion(chunk->getShardId()),
-                                                        _manager->getConfigOpTime()));
+    *endpoint = new ShardEndpoint(chunk->getShardId(), _manager->getVersion(chunk->getShardId()));
 
     return Status::OK();
 }
@@ -543,10 +537,7 @@ Status ChunkManagerTargeter::targetCollection(vector<ShardEndpoint*>* endpoints)
 
     for (const ShardId& shardId : shardIds) {
         endpoints->push_back(new ShardEndpoint(
-            shardId,
-            _manager
-                ? ChunkVersionAndOpTime(_manager->getVersion(shardId), _manager->getConfigOpTime())
-                : ChunkVersionAndOpTime(ChunkVersion::UNSHARDED())));
+            shardId, _manager ? _manager->getVersion(shardId) : ChunkVersion::UNSHARDED()));
     }
 
     return Status::OK();
@@ -564,10 +555,7 @@ Status ChunkManagerTargeter::targetAllShards(vector<ShardEndpoint*>* endpoints)
 
     for (const ShardId& shardId : shardIds) {
         endpoints->push_back(new ShardEndpoint(
-            shardId,
-            _manager
-                ? ChunkVersionAndOpTime(_manager->getVersion(shardId), _manager->getConfigOpTime())
-                : ChunkVersionAndOpTime(ChunkVersion::UNSHARDED())));
+            shardId, _manager ? _manager->getVersion(shardId) : ChunkVersion::UNSHARDED()));
     }
 
     return Status::OK();
diff --git a/src/mongo/s/chunk_version.cpp b/src/mongo/s/chunk_version.cpp
deleted file mode 100644
index 305875d4a6e..00000000000
--- a/src/mongo/s/chunk_version.cpp
+++ /dev/null
@@ -1,152 +0,0 @@
-/**
- *    Copyright (C) 2015 MongoDB Inc.
- *
- *    This program is free software: you can redistribute it and/or  modify
- *    it under the terms of the GNU Affero General Public License, version 3,
- *    as published by the Free Software Foundation.
- *
- *    This program is distributed in the hope that it will be useful,
- *    but WITHOUT ANY WARRANTY; without even the implied warranty of
- *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *    GNU Affero General Public License for more details.
- *
- *    You should have received a copy of the GNU Affero General Public License
- *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- *    As a special exception, the copyright holders give permission to link the
- *    code of portions of this program with the OpenSSL library under certain
- *    conditions as described in each individual source file and distribute
- *    linked combinations including the program with the OpenSSL library. You
- *    must comply with the GNU Affero General Public License in all respects for
- *    all of the code used other than as permitted herein. If you modify file(s)
- *    with this exception, you may extend this exception to your version of the
- *    file(s), but you are not obligated to do so. If you do not wish to do so,
- *    delete this exception statement from your version. If you delete this
- *    exception statement from all source files in the program, then also delete
- *    it in the license file.
- */
-
-#include "mongo/platform/basic.h"
-
-#include "mongo/s/chunk_version.h"
-
-#include "mongo/bson/bsonobj.h"
-#include "mongo/bson/bsonobjbuilder.h"
-#include "mongo/base/status_with.h"
-#include "mongo/bson/util/bson_extract.h"
-#include "mongo/util/mongoutils/str.h"
-
-namespace mongo {
-namespace {
-
-const char kVersion[] = "version";
-const char kShardVersion[] = "shardVersion";
-
-}  // namespace
-
-StatusWith<ChunkVersion> ChunkVersion::parseFromBSONForCommands(const BSONObj& obj) {
-    BSONElement versionElem;
-    Status status = bsonExtractField(obj, kShardVersion, &versionElem);
-    if (!status.isOK())
-        return status;
-
-    if (versionElem.type() != Array) {
-        return {ErrorCodes::TypeMismatch,
-                str::stream() << "Invalid type " << versionElem.type()
-                              << " for shardVersion element. Expected an array"};
-    }
-
-    BSONObjIterator it(versionElem.Obj());
-    if (!it.more())
-        return {ErrorCodes::BadValue, "Unexpected empty version"};
-
-    ChunkVersion version;
-
-    // Expect the timestamp
-    {
-        BSONElement tsPart = it.next();
-        if (tsPart.type() != bsonTimestamp)
-            return {ErrorCodes::TypeMismatch,
-                    str::stream() << "Invalid type " << tsPart.type()
-                                  << " for version timestamp part."};
-
-        version._combined = tsPart.timestamp().asULL();
-    }
-
-    // Expect the epoch OID
-    {
-        BSONElement epochPart = it.next();
-        if (epochPart.type() != jstOID)
-            return {ErrorCodes::TypeMismatch,
-                    str::stream() << "Invalid type " << epochPart.type()
-                                  << " for version epoch part."};
-
-        version._epoch = epochPart.OID();
-    }
-
-    return version;
-}
-
-StatusWith<ChunkVersion> ChunkVersion::parseFromBSONForSetShardVersion(const BSONObj& obj) {
-    bool canParse;
-    const ChunkVersion chunkVersion = ChunkVersion::fromBSON(obj, kVersion, &canParse);
-    if (!canParse)
-        return {ErrorCodes::BadValue, "Unable to parse shard version"};
-
-    return chunkVersion;
-}
-
-
-ChunkVersionAndOpTime::ChunkVersionAndOpTime(ChunkVersion chunkVersion)
-    : _verAndOpT(chunkVersion) {}
-
-ChunkVersionAndOpTime::ChunkVersionAndOpTime(ChunkVersion chunkVersion, repl::OpTime ts)
-    : _verAndOpT(chunkVersion, ts) {}
-
-StatusWith<ChunkVersionAndOpTime> ChunkVersionAndOpTime::parseFromBSONForCommands(
-    const BSONObj& obj) {
-    const auto chunkVersionStatus = ChunkVersion::parseFromBSONForCommands(obj);
-    if (!chunkVersionStatus.isOK())
-        return chunkVersionStatus.getStatus();
-
-    const ChunkVersion& chunkVersion = chunkVersionStatus.getValue();
-
-    const auto opTimeStatus = repl::OpTime::parseFromBSON(obj);
-    if (opTimeStatus.isOK()) {
-        return ChunkVersionAndOpTime(chunkVersion, opTimeStatus.getValue());
-    } else if (opTimeStatus == ErrorCodes::NoSuchKey) {
-        return ChunkVersionAndOpTime(chunkVersion);
-    }
-
-    return opTimeStatus.getStatus();
-}
-
-StatusWith<ChunkVersionAndOpTime> ChunkVersionAndOpTime::parseFromBSONForSetShardVersion(
-    const BSONObj& obj) {
-    const auto chunkVersionStatus = ChunkVersion::parseFromBSONForSetShardVersion(obj);
-    if (!chunkVersionStatus.isOK())
-        return chunkVersionStatus.getStatus();
-
-    const ChunkVersion& chunkVersion = chunkVersionStatus.getValue();
-
-    const auto opTimeStatus = repl::OpTime::parseFromBSON(obj);
-    if (opTimeStatus.isOK()) {
-        return ChunkVersionAndOpTime(chunkVersion, opTimeStatus.getValue());
-    } else if (opTimeStatus == ErrorCodes::NoSuchKey) {
-        return ChunkVersionAndOpTime(chunkVersion);
-    }
-
-    return opTimeStatus.getStatus();
-}
-
-void ChunkVersionAndOpTime::appendForSetShardVersion(BSONObjBuilder* builder) const {
-    _verAndOpT.value.addToBSON(*builder, kVersion);
-    _verAndOpT.opTime.append(builder);
-}
-
-void ChunkVersionAndOpTime::appendForCommands(BSONObjBuilder* builder) const {
-    builder->appendArray(kShardVersion, _verAndOpT.value.toBSON());
-    _verAndOpT.opTime.append(builder);
-}
-
-}  // namespace mongo
diff --git a/src/mongo/s/chunk_version.h b/src/mongo/s/chunk_version.h
index 7c4b2655412..02a05f3dd57 100644
--- a/src/mongo/s/chunk_version.h
+++ b/src/mongo/s/chunk_version.h
@@ -1,42 +1,37 @@
 /**
- *    Copyright (C) 2012-2015 MongoDB Inc.
- *
- *    This program is free software: you can redistribute it and/or  modify
- *    it under the terms of the GNU Affero General Public License, version 3,
- *    as published by the Free Software Foundation.
- *
- *    This program is distributed in the hope that it will be useful,
- *    but WITHOUT ANY WARRANTY; without even the implied warranty of
- *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *    GNU Affero General Public License for more details.
- *
- *    You should have received a copy of the GNU Affero General Public License
- *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- *    As a special exception, the copyright holders give permission to link the
- *    code of portions of this program with the OpenSSL library under certain
- *    conditions as described in each individual source file and distribute
- *    linked combinations including the program with the OpenSSL library. You
- *    must comply with the GNU Affero General Public License in all respects for
- *    all of the code used other than as permitted herein. If you modify file(s)
- *    with this exception, you may extend this exception to your version of the
- *    file(s), but you are not obligated to do so. If you do not wish to do so,
- *    delete this exception statement from your version. If you delete this
- *    exception statement from all source files in the program, then also delete
- *    it in the license file.
- */
+*    Copyright (C) 2012 10gen Inc.
+*
+*    This program is free software: you can redistribute it and/or  modify
+*    it under the terms of the GNU Affero General Public License, version 3,
+*    as published by the Free Software Foundation.
+*
+*    This program is distributed in the hope that it will be useful,
+*    but WITHOUT ANY WARRANTY; without even the implied warranty of
+*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*    GNU Affero General Public License for more details.
+*
+*    You should have received a copy of the GNU Affero General Public License
+*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*
+*    As a special exception, the copyright holders give permission to link the
+*    code of portions of this program with the OpenSSL library under certain
+*    conditions as described in each individual source file and distribute
+*    linked combinations including the program with the OpenSSL library. You
+*    must comply with the GNU Affero General Public License in all respects
+*    for all of the code used other than as permitted herein. If you modify
+*    file(s) with this exception, you may extend this exception to your
+*    version of the file(s), but you are not obligated to do so. If you do not
+*    wish to do so, delete this exception statement from your version. If you
+*    delete this exception statement from all source files in the program,
+*    then also delete it in the license file.
+*/
 
 #pragma once
 
 #include "mongo/db/jsobj.h"
-#include "mongo/db/repl/optime_pair.h"
 
 namespace mongo {
 
-class BSONObj;
-template <typename T>
-class StatusWith;
-
 /**
  * ChunkVersions consist of a major/minor version scoped to a version epoch
  *
@@ -51,38 +46,32 @@ class StatusWith;
  * expected from types.
  */
 struct ChunkVersion {
-public:
+    union {
+        struct {
+            int _minor;
+            int _major;
+        };
+        unsigned long long _combined;
+    };
+    OID _epoch;
+
     ChunkVersion() : _minor(0), _major(0), _epoch(OID()) {}
 
+    //
+    // Constructors shouldn't have default parameters here, since it's vital we track from
+    // here on the epochs of versions, even if not used.
+    //
+
     ChunkVersion(int major, int minor, const OID& epoch)
         : _minor(minor), _major(major), _epoch(epoch) {}
 
-    /**
-     * Interprets the specified BSON content as the format for commands, which is in the form:
-     *  { ..., shardVersion: [ <combined major/minor>, <OID epoch> ], ... }
-     */
-    static StatusWith<ChunkVersion> parseFromBSONForCommands(const BSONObj& obj);
-
-    /**
-     * Interprets the specified BSON content as the format for the setShardVersion command, which
-     * is in the form:
-     *  { ..., version: [ <combined major/minor> ], versionEpoch: [ <OID epoch> ], ... }
-     */
-    static StatusWith<ChunkVersion> parseFromBSONForSetShardVersion(const BSONObj& obj);
-
-    /**
-     * Indicates a dropped collection. All components are zeroes (OID is zero time, zero
-     * machineId/inc).
-     */
     static ChunkVersion DROPPED() {
-        return ChunkVersion(0, 0, OID());
+        return ChunkVersion(0, 0, OID());  // dropped OID is zero time, zero machineId/inc
     }
 
-    /**
-     * Indicates that the collection is not sharded. Same as DROPPED.
-     */
     static ChunkVersion UNSHARDED() {
-        return ChunkVersion(0, 0, OID());
+        // TODO: Distinguish between these cases
+        return DROPPED();
     }
 
     static ChunkVersion IGNORED() {
@@ -380,23 +369,35 @@ public:
         return b.arr();
     }
 
+    bool parseBSON(const BSONObj& source, std::string* errMsg) {
+        // ChunkVersion wants to be an array.
+        BSONArray arrSource = static_cast<BSONArray>(source);
+
+        bool canParse;
+        ChunkVersion version = fromBSON(arrSource, &canParse);
+        if (!canParse) {
+            *errMsg = "Could not parse version structure";
+            return false;
+        }
+
+        _minor = version._minor;
+        _major = version._major;
+        _epoch = version._epoch;
+        return true;
+    }
+
     void clear() {
         _minor = 0;
         _major = 0;
         _epoch = OID();
     }
 
-private:
-    union {
-        struct {
-            int _minor;
-            int _major;
-        };
-
-        uint64_t _combined;
-    };
-
-    OID _epoch;
+    void cloneTo(ChunkVersion* other) const {
+        other->clear();
+        other->_minor = _minor;
+        other->_major = _major;
+        other->_epoch = _epoch;
+    }
 };
 
 inline std::ostream& operator<<(std::ostream& s, const ChunkVersion& v) {
@@ -404,51 +405,4 @@ inline std::ostream& operator<<(std::ostream& s, const ChunkVersion& v) {
     return s;
 }
 
-
-/**
- * Represents a chunk version along with the optime from when it was retrieved. Provides logic to
- * serialize and deserialize the combo to BSON.
- */
-class ChunkVersionAndOpTime {
-public:
-    ChunkVersionAndOpTime(ChunkVersion chunkVersion);
-    ChunkVersionAndOpTime(ChunkVersion chunkVersion, repl::OpTime ts);
-
-    const ChunkVersion& getVersion() const {
-        return _verAndOpT.value;
-    }
-
-    const repl::OpTime& getOpTime() const {
-        return _verAndOpT.opTime;
-    }
-
-    /**
-     * Interprets the contents of the BSON documents as having been constructed in the format for
-     * write commands. The optime component is optional for backwards compatibility and if not
-     * present, the optime will be default initialized.
-     */
-    static StatusWith<ChunkVersionAndOpTime> parseFromBSONForCommands(const BSONObj& obj);
-
-    /**
-     * Interprets the contents of the BSON document as having been constructed in the format for the
-     * setShardVersion command. The optime component is optional for backwards compatibility and if
-     * not present, the optime will be default initialized.
-     */
-    static StatusWith<ChunkVersionAndOpTime> parseFromBSONForSetShardVersion(const BSONObj& obj);
-
-    /**
-     * Appends the contents to the specified builder in the format expected by the setShardVersion
-     * command.
-     */
-    void appendForSetShardVersion(BSONObjBuilder* builder) const;
-
-    /**
-     * Appends the contents to the specified builder in the format expected by the write commands.
-     */
-    void appendForCommands(BSONObjBuilder* builder) const;
-
-private:
-    repl::OpTimePair<ChunkVersion> _verAndOpT;
-};
-
 }  // namespace mongo
diff --git a/src/mongo/s/mock_ns_targeter.h b/src/mongo/s/mock_ns_targeter.h
index 79c6d517445..44bc5be18c2 100644
--- a/src/mongo/s/mock_ns_targeter.h
+++ b/src/mongo/s/mock_ns_targeter.h
@@ -211,11 +211,8 @@ private:
 
 inline void assertEndpointsEqual(const ShardEndpoint& endpointA, const ShardEndpoint& endpointB) {
     ASSERT_EQUALS(endpointA.shardName, endpointB.shardName);
-    ASSERT_EQUALS(endpointA.shardVersion.getVersion().toLong(),
-                  endpointB.shardVersion.getVersion().toLong());
-    ASSERT_EQUALS(endpointA.shardVersion.getVersion().epoch(),
-                  endpointB.shardVersion.getVersion().epoch());
-    ASSERT_EQUALS(endpointA.shardVersion.getOpTime(), endpointB.shardVersion.getOpTime());
+    ASSERT_EQUALS(endpointA.shardVersion.toLong(), endpointB.shardVersion.toLong());
+    ASSERT_EQUALS(endpointA.shardVersion.epoch(), endpointB.shardVersion.epoch());
 }
 
 }  // namespace mongo
diff --git a/src/mongo/s/ns_targeter.h b/src/mongo/s/ns_targeter.h
index 1e6182b67b7..087725697d2 100644
--- a/src/mongo/s/ns_targeter.h
+++ b/src/mongo/s/ns_targeter.h
@@ -157,11 +157,26 @@ struct ShardEndpoint {
     ShardEndpoint(const ShardEndpoint& other)
         : shardName(other.shardName), shardVersion(other.shardVersion) {}
 
-    ShardEndpoint(const std::string& shardName, const ChunkVersionAndOpTime& shardVersion)
+    ShardEndpoint(const std::string& shardName, const ChunkVersion& shardVersion)
         : shardName(shardName), shardVersion(shardVersion) {}
 
     const std::string shardName;
-    const ChunkVersionAndOpTime shardVersion;
+    const ChunkVersion shardVersion;
+
+    //
+    // For testing *only* - do not use as part of API
+    //
+
+    BSONObj toBSON() const {
+        BSONObjBuilder b;
+        appendBSON(&b);
+        return b.obj();
+    }
+
+    void appendBSON(BSONObjBuilder* builder) const {
+        builder->append("shardName", shardName);
+        shardVersion.addToBSON(*builder, "shardVersion");
+    }
 };
 
 }  // namespace mongo
diff --git a/src/mongo/s/set_shard_version_request.cpp b/src/mongo/s/set_shard_version_request.cpp
index 15389a66d43..eb843a963dd 100644
--- a/src/mongo/s/set_shard_version_request.cpp
+++ b/src/mongo/s/set_shard_version_request.cpp
@@ -46,6 +46,7 @@ const char kShardName[] = "shard";
 const char kShardConnectionString[] = "shardHost";
 const char kInit[] = "init";
 const char kAuthoritative[] = "authoritative";
+const char kVersion[] = "version";
 const char kNoConnectionVersioning[] = "noConnectionVersioning";
 
 }  // namespace
@@ -63,7 +64,7 @@ SetShardVersionRequest::SetShardVersionRequest(ConnectionString configServer,
                                                std::string shardName,
                                                ConnectionString shardConnectionString,
                                                NamespaceString nss,
-                                               ChunkVersionAndOpTime version,
+                                               ChunkVersion version,
                                                bool isAuthoritative)
     : _init(false),
       _isAuthoritative(isAuthoritative),
@@ -87,7 +88,7 @@ SetShardVersionRequest SetShardVersionRequest::makeForVersioning(
     const std::string& shardName,
     const ConnectionString& shardConnectionString,
     const NamespaceString& nss,
-    const ChunkVersionAndOpTime& nssVersion,
+    const ChunkVersion& nssVersion,
     bool isAuthoritative) {
     return SetShardVersionRequest(
         configServer, shardName, shardConnectionString, nss, nssVersion, isAuthoritative);
@@ -98,7 +99,7 @@ SetShardVersionRequest SetShardVersionRequest::makeForVersioningNoPersist(
     const std::string& shardName,
     const ConnectionString& shard,
     const NamespaceString& nss,
-    const ChunkVersionAndOpTime& nssVersion,
+    const ChunkVersion& nssVersion,
     bool isAuthoritative) {
     auto ssv = makeForVersioning(configServer, shardName, shard, nss, nssVersion, isAuthoritative);
     ssv._noConnectionVersioning = true;
@@ -184,11 +185,14 @@ StatusWith<SetShardVersionRequest> SetShardVersionRequest::parseFromBSON(const B
     }
 
     {
-        auto versionStatus = ChunkVersionAndOpTime::parseFromBSONForSetShardVersion(cmdObj);
-        if (!versionStatus.isOK())
-            return versionStatus.getStatus();
+        bool canParse;
 
-        request._version = versionStatus.getValue();
+        ChunkVersion chunkVersion = ChunkVersion::fromBSON(cmdObj, kVersion, &canParse);
+        if (!canParse) {
+            return {ErrorCodes::BadValue, "Unable to parse shard version"};
+        }
+
+        request._version = std::move(chunkVersion);
     }
 
     return request;
@@ -205,7 +209,7 @@ BSONObj SetShardVersionRequest::toBSON() const {
     cmdBuilder.append(kShardConnectionString, _shardCS.toString());
 
     if (!_init) {
-        _version.get().appendForSetShardVersion(&cmdBuilder);
+        _version.get().addToBSON(cmdBuilder, kVersion);
     }
 
     if (_noConnectionVersioning) {
@@ -222,7 +226,7 @@ const NamespaceString& SetShardVersionRequest::getNS() const {
 
 const ChunkVersion SetShardVersionRequest::getNSVersion() const {
     invariant(!_init);
-    return _version.get().getVersion();
+    return _version.get();
 }
 
 }  // namespace mongo
diff --git a/src/mongo/s/set_shard_version_request.h b/src/mongo/s/set_shard_version_request.h
index 3f06b4546c8..02fcb3099dc 100644
--- a/src/mongo/s/set_shard_version_request.h
+++ b/src/mongo/s/set_shard_version_request.h
@@ -38,6 +38,7 @@
 namespace mongo {
 
 class BSONObj;
+struct ChunkVersion;
 template <typename T>
 class StatusWith;
 
@@ -66,7 +67,7 @@ public:
                                                     const std::string& shardName,
                                                     const ConnectionString& shard,
                                                     const NamespaceString& nss,
-                                                    const ChunkVersionAndOpTime& nssVersion,
+                                                    const ChunkVersion& nssVersion,
                                                     bool isAuthoritative);
 
     /**
@@ -76,13 +77,12 @@ public:
      * connection WILL NOT be marked as "versioned". DO NOT USE unless the command will be sent
      * through the TaskExecutor.
      */
-    static SetShardVersionRequest makeForVersioningNoPersist(
-        const ConnectionString& configServer,
-        const std::string& shardName,
-        const ConnectionString& shard,
-        const NamespaceString& nss,
-        const ChunkVersionAndOpTime& nssVersion,
-        bool isAuthoritative);
+    static SetShardVersionRequest makeForVersioningNoPersist(const ConnectionString& configServer,
+                                                             const std::string& shardName,
+                                                             const ConnectionString& shard,
+                                                             const NamespaceString& nss,
+                                                             const ChunkVersion& nssVersion,
+                                                             bool isAuthoritative);
 
     /**
      * Parses an SSV request from a set shard version command.
@@ -153,7 +153,7 @@ private:
                            std::string shardName,
                            ConnectionString shardConnectionString,
                            NamespaceString nss,
-                           ChunkVersionAndOpTime version,
+                           ChunkVersion nssVersion,
                            bool isAuthoritative);
 
     SetShardVersionRequest();
@@ -169,7 +169,7 @@ private:
 
     // These values are only set if _init is false
     boost::optional<NamespaceString> _nss;
-    boost::optional<ChunkVersionAndOpTime> _version;
+    boost::optional<ChunkVersion> _version;
 };
 
 }  // namespace mongo
diff --git a/src/mongo/s/set_shard_version_request_test.cpp b/src/mongo/s/set_shard_version_request_test.cpp
index ab370835f7a..6328a9763c2 100644
--- a/src/mongo/s/set_shard_version_request_test.cpp
+++ b/src/mongo/s/set_shard_version_request_test.cpp
@@ -215,8 +215,7 @@ TEST(SetShardVersionRequest, ToSSVCommandInit) {
 }
 
 TEST(SetShardVersionRequest, ToSSVCommandFull) {
-    const ChunkVersionAndOpTime chunkVersion(ChunkVersion(1, 2, OID::gen()),
-                                             repl::OpTime(Timestamp(10), 20LL));
+    const ChunkVersion chunkVersion(1, 2, OID::gen());
 
     SetShardVersionRequest ssv = SetShardVersionRequest::makeForVersioning(
         configCS, "TestShard", shardCS, NamespaceString("db.coll"), chunkVersion, false);
@@ -229,7 +228,7 @@ TEST(SetShardVersionRequest, ToSSVCommandFull) {
     ASSERT_EQ(ssv.getShardConnectionString().toString(), shardCS.toString());
     ASSERT_EQ(ssv.getNS().ns(), "db.coll");
     ASSERT_EQ(ssv.getNSVersion().toBSONWithPrefix("version"),
-              chunkVersion.getVersion().toBSONWithPrefix("version"));
+              chunkVersion.toBSONWithPrefix("version"));
 
     ASSERT_EQ(ssv.toBSON(),
               BSON("setShardVersion"
@@ -238,13 +237,11 @@ TEST(SetShardVersionRequest, ToSSVCommandFull) {
                    << configCS.toString() << "shard"
                    << "TestShard"
                    << "shardHost" << shardCS.toString() << "version"
-                   << Timestamp(chunkVersion.getVersion().toLong()) << "versionEpoch"
-                   << chunkVersion.getVersion().epoch() << "ts" << Timestamp(10) << "t" << 20LL));
+                   << Timestamp(chunkVersion.toLong()) << "versionEpoch" << chunkVersion.epoch()));
 }
 
 TEST(SetShardVersionRequest, ToSSVCommandFullAuthoritative) {
-    const ChunkVersionAndOpTime chunkVersion(ChunkVersion(1, 2, OID::gen()),
-                                             repl::OpTime(Timestamp(10), 20LL));
+    const ChunkVersion chunkVersion(1, 2, OID::gen());
 
     SetShardVersionRequest ssv = SetShardVersionRequest::makeForVersioning(
         configCS, "TestShard", shardCS, NamespaceString("db.coll"), chunkVersion, true);
@@ -257,7 +254,7 @@ TEST(SetShardVersionRequest, ToSSVCommandFullAuthoritative) {
     ASSERT_EQ(ssv.getShardConnectionString().toString(), shardCS.toString());
     ASSERT_EQ(ssv.getNS().ns(), "db.coll");
     ASSERT_EQ(ssv.getNSVersion().toBSONWithPrefix("version"),
-              chunkVersion.getVersion().toBSONWithPrefix("version"));
+              chunkVersion.toBSONWithPrefix("version"));
 
     ASSERT_EQ(ssv.toBSON(),
               BSON("setShardVersion"
@@ -266,13 +263,11 @@ TEST(SetShardVersionRequest, ToSSVCommandFullAuthoritative) {
                    << configCS.toString() << "shard"
                    << "TestShard"
                    << "shardHost" << shardCS.toString() << "version"
-                   << Timestamp(chunkVersion.getVersion().toLong()) << "versionEpoch"
-                   << chunkVersion.getVersion().epoch() << "ts" << Timestamp(10) << "t" << 20LL));
+                   << Timestamp(chunkVersion.toLong()) << "versionEpoch" << chunkVersion.epoch()));
 }
 
 TEST(SetShardVersionRequest, ToSSVCommandFullNoConnectionVersioning) {
-    const ChunkVersionAndOpTime chunkVersion(ChunkVersion(1, 2, OID::gen()),
-                                             repl::OpTime(Timestamp(10), 20LL));
+    const ChunkVersion chunkVersion(1, 2, OID::gen());
 
     SetShardVersionRequest ssv = SetShardVersionRequest::makeForVersioningNoPersist(
         configCS, "TestShard", shardCS, NamespaceString("db.coll"), chunkVersion, true);
@@ -285,7 +280,7 @@ TEST(SetShardVersionRequest, ToSSVCommandFullNoConnectionVersioning) {
     ASSERT_EQ(ssv.getShardConnectionString().toString(), shardCS.toString());
     ASSERT_EQ(ssv.getNS().ns(), "db.coll");
     ASSERT_EQ(ssv.getNSVersion().toBSONWithPrefix("version"),
-              chunkVersion.getVersion().toBSONWithPrefix("version"));
+              chunkVersion.toBSONWithPrefix("version"));
 
     ASSERT_EQ(ssv.toBSON(),
               BSON("setShardVersion"
@@ -294,8 +289,7 @@ TEST(SetShardVersionRequest, ToSSVCommandFullNoConnectionVersioning) {
                    << configCS.toString() << "shard"
                    << "TestShard"
                    << "shardHost" << shardCS.toString() << "version"
-                   << Timestamp(chunkVersion.getVersion().toLong()) << "versionEpoch"
-                   << chunkVersion.getVersion().epoch() << "ts" << Timestamp(10) << "t" << 20LL
+                   << Timestamp(chunkVersion.toLong()) << "versionEpoch" << chunkVersion.epoch()
                    << "noConnectionVersioning" << true));
 }
 
diff --git a/src/mongo/s/version_manager.cpp b/src/mongo/s/version_manager.cpp
index 4d4f87a3159..a77243627d5 100644
--- a/src/mongo/s/version_manager.cpp
+++ b/src/mongo/s/version_manager.cpp
@@ -1,30 +1,32 @@
+// @file version_manager.cpp
+
 /**
- *    Copyright (C) 2010-2015 MongoDB Inc.
- *
- *    This program is free software: you can redistribute it and/or  modify
- *    it under the terms of the GNU Affero General Public License, version 3,
- *    as published by the Free Software Foundation.
- *
- *    This program is distributed in the hope that it will be useful,
- *    but WITHOUT ANY WARRANTY; without even the implied warranty of
- *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *    GNU Affero General Public License for more details.
- *
- *    You should have received a copy of the GNU Affero General Public License
- *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- *    As a special exception, the copyright holders give permission to link the
- *    code of portions of this program with the OpenSSL library under certain
- *    conditions as described in each individual source file and distribute
- *    linked combinations including the program with the OpenSSL library. You
- *    must comply with the GNU Affero General Public License in all respects for
- *    all of the code used other than as permitted herein. If you modify file(s)
- *    with this exception, you may extend this exception to your version of the
- *    file(s), but you are not obligated to do so. If you do not wish to do so,
- *    delete this exception statement from your version. If you delete this
- *    exception statement from all source files in the program, then also delete
- *    it in the license file.
- */
+*    Copyright (C) 2010 10gen Inc.
+*
+*    This program is free software: you can redistribute it and/or  modify
+*    it under the terms of the GNU Affero General Public License, version 3,
+*    as published by the Free Software Foundation.
+*
+*    This program is distributed in the hope that it will be useful,
+*    but WITHOUT ANY WARRANTY; without even the implied warranty of
+*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*    GNU Affero General Public License for more details.
+*
+*    You should have received a copy of the GNU Affero General Public License
+*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*
+*    As a special exception, the copyright holders give permission to link the
+*    code of portions of this program with the OpenSSL library under certain
+*    conditions as described in each individual source file and distribute
+*    linked combinations including the program with the OpenSSL library. You
+*    must comply with the GNU Affero General Public License in all respects
+*    for all of the code used other than as permitted herein. If you modify
+*    file(s) with this exception, you may extend this exception to your
+*    version of the file(s), but you are not obligated to do so. If you do not
+*    wish to do so, delete this exception statement from your version. If you
+*    delete this exception statement from all source files in the program,
+*    then also delete it in the license file.
+*/
 
 #define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kSharding
 
@@ -43,7 +45,6 @@
 #include "mongo/s/config.h"
 #include "mongo/s/grid.h"
 #include "mongo/s/mongos_options.h"
-#include "mongo/s/set_shard_version_request.h"
 #include "mongo/s/stale_exception.h"
 #include "mongo/util/log.h"
 
@@ -110,36 +111,35 @@ private:
  */
 bool setShardVersion(DBClientBase& conn,
                      const string& ns,
-                     const ConnectionString& configServer,
+                     const string& configServerPrimary,
                      ChunkVersion version,
                      ChunkManager* manager,
                      bool authoritative,
                      BSONObj& result) {
+    BSONObjBuilder cmdBuilder;
+    cmdBuilder.append("setShardVersion", ns);
+    cmdBuilder.append("configdb", configServerPrimary);
+
     ShardId shardId;
-    ConnectionString shardCS;
     {
         const auto shard = grid.shardRegistry()->getShard(conn.getServerAddress());
         shardId = shard->getId();
-        shardCS = shard->getConnString();
+        cmdBuilder.append("shard", shardId);
+        cmdBuilder.append("shardHost", shard->getConnString().toString());
     }
 
-    BSONObj cmd;
-
-    if (ns.empty()) {
-        SetShardVersionRequest ssv =
-            SetShardVersionRequest::makeForInit(configServer, shardId, shardCS);
-        cmd = ssv.toBSON();
+    if (ns.size() > 0) {
+        version.addToBSON(cmdBuilder);
     } else {
-        const ChunkVersionAndOpTime verAndOpT = manager
-            ? ChunkVersionAndOpTime(version, manager->getConfigOpTime())
-            : ChunkVersionAndOpTime(version);
-
-        SetShardVersionRequest ssv = SetShardVersionRequest::makeForVersioning(
-            configServer, shardId, shardCS, NamespaceString(ns), verAndOpT, authoritative);
+        cmdBuilder.append("init", true);
+    }
 
-        cmd = ssv.toBSON();
+    if (authoritative) {
+        cmdBuilder.appendBool("authoritative", 1);
     }
 
+    BSONObj cmd = cmdBuilder.obj();
+
     LOG(1) << "    setShardVersion  " << shardId << " " << conn.getServerAddress() << "  " << ns
            << "  " << cmd
            << (manager ? string(str::stream() << " " << manager->getSequenceNumber()) : "");
@@ -214,7 +214,7 @@ bool initShardVersionEmptyNS(OperationContext* txn, DBClientBase* conn_in) {
 
         ok = setShardVersion(*conn,
                              "",
-                             grid.shardRegistry()->getConfigServerConnectionString(),
+                             grid.shardRegistry()->getConfigServerConnectionString().toString(),
                              ChunkVersion(),
                              NULL,
                              true,
@@ -373,7 +373,7 @@ bool checkShardVersion(OperationContext* txn,
     BSONObj result;
     if (setShardVersion(*conn,
                         ns,
-                        grid.shardRegistry()->getConfigServerConnectionString(),
+                        grid.shardRegistry()->getConfigServerConnectionString().toString(),
                         version,
                         manager.get(),
                         authoritative,
diff --git a/src/mongo/s/write_ops/batch_write_op.cpp b/src/mongo/s/write_ops/batch_write_op.cpp
index ba7ddae8d95..113dd9133f8 100644
--- a/src/mongo/s/write_ops/batch_write_op.cpp
+++ b/src/mongo/s/write_ops/batch_write_op.cpp
@@ -87,13 +87,11 @@ static int compareEndpoints(const ShardEndpoint* endpointA, const ShardEndpoint*
     if (shardNameDiff != 0)
         return shardNameDiff;
 
-    long shardVersionDiff = endpointA->shardVersion.getVersion().toLong() -
-        endpointB->shardVersion.getVersion().toLong();
+    long shardVersionDiff = endpointA->shardVersion.toLong() - endpointB->shardVersion.toLong();
     if (shardVersionDiff != 0)
         return shardVersionDiff;
 
-    int shardEpochDiff = endpointA->shardVersion.getVersion().epoch().compare(
-        endpointB->shardVersion.getVersion().epoch());
+    int shardEpochDiff = endpointA->shardVersion.epoch().compare(endpointB->shardVersion.epoch());
     return shardEpochDiff;
 }
 
@@ -458,8 +456,7 @@ void BatchWriteOp::buildBatchRequest(const TargetedWriteBatch& targetedBatch,
 
     unique_ptr<BatchedRequestMetadata> requestMetadata(new BatchedRequestMetadata());
     requestMetadata->setShardName(targetedBatch.getEndpoint().shardName);
-    requestMetadata->setShardVersion(
-        ChunkVersionAndOpTime(targetedBatch.getEndpoint().shardVersion));
+    requestMetadata->setShardVersion(targetedBatch.getEndpoint().shardVersion);
     requestMetadata->setSession(0);
     request->setMetadata(requestMetadata.release());
 }
diff --git a/src/mongo/s/write_ops/batched_delete_request_test.cpp b/src/mongo/s/write_ops/batched_delete_request_test.cpp
index c8f71652599..87d883f1b0b 100644
--- a/src/mongo/s/write_ops/batched_delete_request_test.cpp
+++ b/src/mongo/s/write_ops/batched_delete_request_test.cpp
@@ -46,24 +46,32 @@ TEST(BatchedDeleteRequest, Basic) {
         BSON(BatchedDeleteDocument::query(BSON("a" << 1)) << BatchedDeleteDocument::limit(1))
         << BSON(BatchedDeleteDocument::query(BSON("b" << 1)) << BatchedDeleteDocument::limit(1)));
 
-    BSONObj origDeleteRequestObj = BSON(
-        BatchedDeleteRequest::collName("test")
-        << BatchedDeleteRequest::deletes() << deleteArray
-        << BatchedDeleteRequest::writeConcern(BSON("w" << 1)) << BatchedDeleteRequest::ordered(true)
-        << BatchedDeleteRequest::metadata() << BSON("shardName"
-                                                    << "shard000"
-                                                    << "shardVersion"
-                                                    << BSON_ARRAY(Timestamp(1, 2) << OID::gen())
-                                                    << "ts" << Timestamp(3, 4) << "t" << 5
-                                                    << "session" << 0LL));
+    BSONObj writeConcernObj = BSON("w" << 1);
+
+    // The BSON_ARRAY macro doesn't support Timestamps.
+    BSONArrayBuilder arrBuilder;
+    arrBuilder.append(Timestamp(1, 1));
+    arrBuilder.append(OID::gen());
+    BSONArray shardVersionArray = arrBuilder.arr();
+
+    BSONObj origDeleteRequestObj =
+        BSON(BatchedDeleteRequest::collName("test")
+             << BatchedDeleteRequest::deletes() << deleteArray
+             << BatchedDeleteRequest::writeConcern(writeConcernObj)
+             << BatchedDeleteRequest::ordered(true) << BatchedDeleteRequest::metadata()
+             << BSON(BatchedRequestMetadata::shardName("shard000")
+                     << BatchedRequestMetadata::shardVersion() << shardVersionArray
+                     << BatchedRequestMetadata::session(0)));
 
     string errMsg;
     BatchedDeleteRequest request;
-    ASSERT_TRUE(request.parseBSON("foo", origDeleteRequestObj, &errMsg));
+    bool ok = request.parseBSON("foo", origDeleteRequestObj, &errMsg);
+    ASSERT_TRUE(ok);
 
     ASSERT_EQ("foo.test", request.getNS().ns());
 
-    ASSERT_EQUALS(origDeleteRequestObj, request.toBSON());
+    BSONObj genDeleteRequestObj = request.toBSON();
+    ASSERT_EQUALS(0, genDeleteRequestObj.woCompare(origDeleteRequestObj));
 }
 
 }  // namespace
diff --git a/src/mongo/s/write_ops/batched_insert_request_test.cpp b/src/mongo/s/write_ops/batched_insert_request_test.cpp
index 09e8e950c08..e31503d431f 100644
--- a/src/mongo/s/write_ops/batched_insert_request_test.cpp
+++ b/src/mongo/s/write_ops/batched_insert_request_test.cpp
@@ -45,24 +45,32 @@ namespace {
 TEST(BatchedInsertRequest, Basic) {
     BSONArray insertArray = BSON_ARRAY(BSON("a" << 1) << BSON("b" << 1));
 
-    BSONObj origInsertRequestObj = BSON(
-        BatchedInsertRequest::collName("test")
-        << BatchedInsertRequest::documents() << insertArray
-        << BatchedInsertRequest::writeConcern(BSON("w" << 1)) << BatchedInsertRequest::ordered(true)
-        << BatchedInsertRequest::metadata() << BSON("shardName"
-                                                    << "shard000"
-                                                    << "shardVersion"
-                                                    << BSON_ARRAY(Timestamp(1, 2) << OID::gen())
-                                                    << "ts" << Timestamp(3, 4) << "t" << 5
-                                                    << "session" << 0LL));
+    BSONObj writeConcernObj = BSON("w" << 1);
+
+    // The BSON_ARRAY macro doesn't support Timestamps.
+    BSONArrayBuilder arrBuilder;
+    arrBuilder.append(Timestamp(1, 1));
+    arrBuilder.append(OID::gen());
+    BSONArray shardVersionArray = arrBuilder.arr();
+
+    BSONObj origInsertRequestObj =
+        BSON(BatchedInsertRequest::collName("test")
+             << BatchedInsertRequest::documents() << insertArray
+             << BatchedInsertRequest::writeConcern(writeConcernObj)
+             << BatchedInsertRequest::ordered(true) << BatchedInsertRequest::metadata()
+             << BSON(BatchedRequestMetadata::shardName("shard0000")
+                     << BatchedRequestMetadata::shardVersion() << shardVersionArray
+                     << BatchedRequestMetadata::session(0)));
 
     string errMsg;
     BatchedInsertRequest request;
-    ASSERT_TRUE(request.parseBSON("foo", origInsertRequestObj, &errMsg));
+    bool ok = request.parseBSON("foo", origInsertRequestObj, &errMsg);
+    ASSERT_TRUE(ok);
 
     ASSERT_EQ("foo.test", request.getNS().ns());
 
-    ASSERT_EQUALS(origInsertRequestObj, request.toBSON());
+    BSONObj genInsertRequestObj = request.toBSON();
+    ASSERT_EQUALS(0, genInsertRequestObj.woCompare(origInsertRequestObj));
 }
 
 TEST(BatchedInsertRequest, GenIDAll) {
diff --git a/src/mongo/s/write_ops/batched_request_metadata.cpp b/src/mongo/s/write_ops/batched_request_metadata.cpp
index 78ecefbb9df..a2e21f99e4c 100644
--- a/src/mongo/s/write_ops/batched_request_metadata.cpp
+++ b/src/mongo/s/write_ops/batched_request_metadata.cpp
@@ -26,8 +26,6 @@
  *    it in the license file.
  */
 
-#include "mongo/platform/basic.h"
-
 #include "mongo/s/write_ops/batched_request_metadata.h"
 
 #include "mongo/db/field_parser.h"
@@ -57,8 +55,9 @@ BSONObj BatchedRequestMetadata::toBSON() const {
     if (_isShardNameSet)
         metadataBuilder << shardName(_shardName);
 
-    if (_shardVersion) {
-        _shardVersion.get().appendForCommands(&metadataBuilder);
+    if (_shardVersion.get()) {
+        // ChunkVersion wants to be an array.
+        metadataBuilder.append(shardVersion(), static_cast<BSONArray>(_shardVersion->toBSON()));
     }
 
     if (_isSessionSet)
@@ -81,12 +80,12 @@ bool BatchedRequestMetadata::parseBSON(const BSONObj& source, string* errMsg) {
     _isShardNameSet = fieldState == FieldParser::FIELD_SET;
 
     {
-        auto verAndOpTStatus = ChunkVersionAndOpTime::parseFromBSONForCommands(source);
-        if (!verAndOpTStatus.isOK()) {
+        std::unique_ptr<ChunkVersion> tempChunkVersion(new ChunkVersion);
+        fieldState = FieldParser::extract(source, shardVersion, tempChunkVersion.get(), errMsg);
+        if (fieldState == FieldParser::FIELD_INVALID)
             return false;
-        }
-
-        _shardVersion = verAndOpTStatus.getValue();
+        if (fieldState == FieldParser::FIELD_SET)
+            _shardVersion.swap(tempChunkVersion);
     }
 
     fieldState = FieldParser::extract(source, session, &_session, errMsg);
@@ -114,7 +113,10 @@ string BatchedRequestMetadata::toString() const {
 void BatchedRequestMetadata::cloneTo(BatchedRequestMetadata* other) const {
     other->_shardName = _shardName;
     other->_isShardNameSet = _isShardNameSet;
-    other->_shardVersion = _shardVersion;
+
+    if (other->_shardVersion.get())
+        _shardVersion->cloneTo(other->_shardVersion.get());
+
     other->_session = _session;
     other->_isSessionSet = _isSessionSet;
 }
@@ -124,21 +126,36 @@ void BatchedRequestMetadata::setShardName(StringData shardName) {
     _isShardNameSet = true;
 }
 
+void BatchedRequestMetadata::unsetShardName() {
+    _isShardNameSet = false;
+}
+
+bool BatchedRequestMetadata::isShardNameSet() const {
+    return _isShardNameSet;
+}
+
 const string& BatchedRequestMetadata::getShardName() const {
     dassert(_isShardNameSet);
     return _shardName;
 }
 
-void BatchedRequestMetadata::setShardVersion(const ChunkVersionAndOpTime& shardVersion) {
-    _shardVersion = shardVersion;
+void BatchedRequestMetadata::setShardVersion(const ChunkVersion& shardVersion) {
+    unique_ptr<ChunkVersion> temp(new ChunkVersion);
+    shardVersion.cloneTo(temp.get());
+    _shardVersion.reset(temp.release());
+}
+
+void BatchedRequestMetadata::unsetShardVersion() {
+    _shardVersion.reset();
 }
 
 bool BatchedRequestMetadata::isShardVersionSet() const {
-    return _shardVersion.is_initialized();
+    return _shardVersion.get() != NULL;
 }
 
 const ChunkVersion& BatchedRequestMetadata::getShardVersion() const {
-    return _shardVersion.get().getVersion();
+    dassert(_shardVersion.get());
+    return *_shardVersion;
 }
 
 void BatchedRequestMetadata::setSession(long long session) {
diff --git a/src/mongo/s/write_ops/batched_request_metadata.h b/src/mongo/s/write_ops/batched_request_metadata.h
index 2b885e9018d..6e31cb60713 100644
--- a/src/mongo/s/write_ops/batched_request_metadata.h
+++ b/src/mongo/s/write_ops/batched_request_metadata.h
@@ -28,33 +28,34 @@
 
 #pragma once
 
-#include <boost/optional.hpp>
 #include <string>
 
+#include "mongo/base/disallow_copying.h"
 #include "mongo/db/jsobj.h"
 #include "mongo/s/bson_serializable.h"
 #include "mongo/s/chunk_version.h"
 
 namespace mongo {
+class BatchedRequestMetadata : public BSONSerializable {
+    MONGO_DISALLOW_COPYING(BatchedRequestMetadata);
 
-class BatchedRequestMetadata {
 public:
     static const BSONField<std::string> shardName;
     static const BSONField<ChunkVersion> shardVersion;
     static const BSONField<long long> session;
 
     BatchedRequestMetadata();
-    ~BatchedRequestMetadata();
+    virtual ~BatchedRequestMetadata();
 
     //
     // bson serializable interface implementation
     //
 
-    bool isValid(std::string* errMsg) const;
-    BSONObj toBSON() const;
-    bool parseBSON(const BSONObj& source, std::string* errMsg);
-    void clear();
-    std::string toString() const;
+    virtual bool isValid(std::string* errMsg) const;
+    virtual BSONObj toBSON() const;
+    virtual bool parseBSON(const BSONObj& source, std::string* errMsg);
+    virtual void clear();
+    virtual std::string toString() const;
 
     void cloneTo(BatchedRequestMetadata* other) const;
 
@@ -63,12 +64,14 @@ public:
     //
 
     void setShardName(StringData shardName);
+    void unsetShardName();
+    bool isShardNameSet() const;
     const std::string& getShardName() const;
 
-    void setShardVersion(const ChunkVersionAndOpTime& shardVersion);
+    void setShardVersion(const ChunkVersion& shardVersion);
+    void unsetShardVersion();
     bool isShardVersionSet() const;
     const ChunkVersion& getShardVersion() const;
-    const repl::OpTime& getOpTime() const;
 
     void setSession(long long session);
     void unsetSession();
@@ -81,11 +84,10 @@ private:
     bool _isShardNameSet;
 
     // (O)  version for this collection on a given shard
-    boost::optional<ChunkVersionAndOpTime> _shardVersion;
+    std::unique_ptr<ChunkVersion> _shardVersion;
 
     // (O)  session number the inserts belong to
     long long _session;
     bool _isSessionSet;
 };
-
-}  // namespace mongo
+}
diff --git a/src/mongo/s/write_ops/batched_request_metadata_test.cpp b/src/mongo/s/write_ops/batched_request_metadata_test.cpp
index 978ee865045..f35bcee4ef9 100644
--- a/src/mongo/s/write_ops/batched_request_metadata_test.cpp
+++ b/src/mongo/s/write_ops/batched_request_metadata_test.cpp
@@ -40,16 +40,22 @@ using std::string;
 namespace {
 
 TEST(BatchedRequestMetadata, Basic) {
-    BSONObj metadataObj(BSON("shardName"
-                             << "shard0000"
-                             << "shardVersion" << BSON_ARRAY(Timestamp(1, 2) << OID::gen()) << "ts"
-                             << Timestamp(3, 4) << "t" << 5 << "session" << 0LL));
+    // The BSON_ARRAY macro doesn't support Timestamps.
+    BSONArrayBuilder arrBuilder;
+    arrBuilder.append(Timestamp(1, 1));
+    arrBuilder.append(OID::gen());
+    BSONArray shardVersionArray = arrBuilder.arr();
+
+    BSONObj metadataObj(BSON(BatchedRequestMetadata::shardName("shard0000")
+                             << BatchedRequestMetadata::shardVersion() << shardVersionArray
+                             << BatchedRequestMetadata::session(100)));
 
     string errMsg;
     BatchedRequestMetadata metadata;
     ASSERT_TRUE(metadata.parseBSON(metadataObj, &errMsg));
 
-    ASSERT_EQUALS(metadataObj, metadata.toBSON());
+    BSONObj genMetadataObj = metadata.toBSON();
+    ASSERT_EQUALS(metadataObj, genMetadataObj);
 }
 
 }  // namespace
diff --git a/src/mongo/s/write_ops/batched_update_request_test.cpp b/src/mongo/s/write_ops/batched_update_request_test.cpp
index af7bb5aadfb..04994733537 100644
--- a/src/mongo/s/write_ops/batched_update_request_test.cpp
+++ b/src/mongo/s/write_ops/batched_update_request_test.cpp
@@ -50,24 +50,32 @@ TEST(BatchedUpdateRequest, Basic) {
                 << BatchedUpdateDocument::updateExpr(BSON("$set" << BSON("b" << 2)))
                 << BatchedUpdateDocument::multi(false) << BatchedUpdateDocument::upsert(false)));
 
-    BSONObj origUpdateRequestObj = BSON(
-        BatchedUpdateRequest::collName("test")
-        << BatchedUpdateRequest::updates() << updateArray
-        << BatchedUpdateRequest::writeConcern(BSON("w" << 1)) << BatchedUpdateRequest::ordered(true)
-        << BatchedUpdateRequest::metadata() << BSON("shardName"
-                                                    << "shard000"
-                                                    << "shardVersion"
-                                                    << BSON_ARRAY(Timestamp(1, 2) << OID::gen())
-                                                    << "ts" << Timestamp(3, 4) << "t" << 5
-                                                    << "session" << 0LL));
+    BSONObj writeConcernObj = BSON("w" << 1);
+
+    // The BSON_ARRAY macro doesn't support Timestamps.
+    BSONArrayBuilder arrBuilder;
+    arrBuilder.append(Timestamp(1, 1));
+    arrBuilder.append(OID::gen());
+    BSONArray shardVersionArray = arrBuilder.arr();
+
+    BSONObj origUpdateRequestObj =
+        BSON(BatchedUpdateRequest::collName("test")
+             << BatchedUpdateRequest::updates() << updateArray
+             << BatchedUpdateRequest::writeConcern(writeConcernObj)
+             << BatchedUpdateRequest::ordered(true) << BatchedUpdateRequest::metadata()
+             << BSON(BatchedRequestMetadata::shardName("shard0000")
+                     << BatchedRequestMetadata::shardVersion() << shardVersionArray
+                     << BatchedRequestMetadata::session(0)));
 
     string errMsg;
     BatchedUpdateRequest request;
-    ASSERT_TRUE(request.parseBSON("foo", origUpdateRequestObj, &errMsg));
+    bool ok = request.parseBSON("foo", origUpdateRequestObj, &errMsg);
+    ASSERT_TRUE(ok);
 
     ASSERT_EQ("foo.test", request.getNS().ns());
 
-    ASSERT_EQUALS(origUpdateRequestObj, request.toBSON());
+    BSONObj genUpdateRequestObj = request.toBSON();
+    ASSERT_EQUALS(0, genUpdateRequestObj.woCompare(origUpdateRequestObj));
 }
 
 }  // namespace
diff --git a/src/mongo/s/write_ops/write_op.cpp b/src/mongo/s/write_ops/write_op.cpp
index 8cd20fa4865..25f9f13b3aa 100644
--- a/src/mongo/s/write_ops/write_op.cpp
+++ b/src/mongo/s/write_ops/write_op.cpp
@@ -127,8 +127,7 @@ Status WriteOp::targetWrites(OperationContext* txn,
         if (endpoints.size() == 1u) {
             targetedWrites->push_back(new TargetedWrite(*endpoint, ref));
         } else {
-            ShardEndpoint broadcastEndpoint(endpoint->shardName,
-                                            ChunkVersionAndOpTime(ChunkVersion::IGNORED()));
+            ShardEndpoint broadcastEndpoint(endpoint->shardName, ChunkVersion::IGNORED());
             targetedWrites->push_back(new TargetedWrite(broadcastEndpoint, ref));
         }
 
diff --git a/src/mongo/s/write_ops/write_op_test.cpp b/src/mongo/s/write_ops/write_op_test.cpp
index 233aa824337..e488c068e47 100644
--- a/src/mongo/s/write_ops/write_op_test.cpp
+++ b/src/mongo/s/write_ops/write_op_test.cpp
@@ -218,11 +218,11 @@ TEST(WriteOpTests, TargetMultiAllShards) {
     ASSERT_EQUALS(targeted.size(), 3u);
     sortByEndpoint(&targeted);
     ASSERT_EQUALS(targeted[0]->endpoint.shardName, endpointA.shardName);
-    ASSERT(ChunkVersion::isIgnoredVersion(targeted[0]->endpoint.shardVersion.getVersion()));
+    ASSERT(ChunkVersion::isIgnoredVersion(targeted[0]->endpoint.shardVersion));
     ASSERT_EQUALS(targeted[1]->endpoint.shardName, endpointB.shardName);
-    ASSERT(ChunkVersion::isIgnoredVersion(targeted[1]->endpoint.shardVersion.getVersion()));
+    ASSERT(ChunkVersion::isIgnoredVersion(targeted[1]->endpoint.shardVersion));
     ASSERT_EQUALS(targeted[2]->endpoint.shardName, endpointC.shardName);
-    ASSERT(ChunkVersion::isIgnoredVersion(targeted[2]->endpoint.shardVersion.getVersion()));
+    ASSERT(ChunkVersion::isIgnoredVersion(targeted[2]->endpoint.shardVersion));
 
     writeOp.noteWriteComplete(*targeted[0]);
     writeOp.noteWriteComplete(*targeted[1]);