SERVER-27543 send OplogQueryMetadata with OplogFetcher queries

11 files changed, 185 insertions, 31 deletions

diff --git a/src/mongo/db/repl/oplog_fetcher.cpp b/src/mongo/db/repl/oplog_fetcher.cpp
index f976b9ac18d..3bc3284bbee 100644
--- a/src/mongo/db/repl/oplog_fetcher.cpp
+++ b/src/mongo/db/repl/oplog_fetcher.cpp
@@ -37,6 +37,7 @@
 #include "mongo/db/jsobj.h"
 #include "mongo/db/repl/replication_coordinator.h"
 #include "mongo/db/stats/timer_stats.h"
+#include "mongo/rpc/metadata/oplog_query_metadata.h"
 #include "mongo/rpc/metadata/server_selection_metadata.h"
 #include "mongo/stdx/memory.h"
 #include "mongo/stdx/mutex.h"
@@ -115,6 +116,8 @@ StatusWith<BSONObj> makeMetadataObject(bool isV1ElectionProtocol) {
     return isV1ElectionProtocol
         ? BSON(rpc::kReplSetMetadataFieldName
                << 1
+               << rpc::kOplogQueryMetadataFieldName
+               << 1
                << rpc::ServerSelectionMetadata::fieldName()
                << BSON(rpc::ServerSelectionMetadata::kSecondaryOkFieldName << true))
         : rpc::ServerSelectionMetadata(true, boost::none).toBSON();
diff --git a/src/mongo/db/repl/oplog_fetcher_test.cpp b/src/mongo/db/repl/oplog_fetcher_test.cpp
index 1c77b47bd3e..5b753cce881 100644
--- a/src/mongo/db/repl/oplog_fetcher_test.cpp
+++ b/src/mongo/db/repl/oplog_fetcher_test.cpp
@@ -35,6 +35,7 @@
 #include "mongo/db/repl/oplog_fetcher.h"
 #include "mongo/executor/thread_pool_task_executor_test_fixture.h"
 #include "mongo/rpc/metadata.h"
+#include "mongo/rpc/metadata/oplog_query_metadata.h"
 #include "mongo/rpc/metadata/repl_set_metadata.h"
 #include "mongo/rpc/metadata/server_selection_metadata.h"
 #include "mongo/stdx/memory.h"
@@ -399,8 +400,9 @@ TEST_F(OplogFetcherTest, MetadataObjectContainsReplSetMetadataFieldUnderProtocol
                                     enqueueDocumentsFn,
                                     [](Status, OpTimeWithHash) {})
                            .getMetadataObject_forTest();
-    ASSERT_EQUALS(2, metadataObj.nFields());
+    ASSERT_EQUALS(3, metadataObj.nFields());
     ASSERT_EQUALS(1, metadataObj[rpc::kReplSetMetadataFieldName].numberInt());
+    ASSERT_EQUALS(1, metadataObj[rpc::kOplogQueryMetadataFieldName].numberInt());
 }
 
 TEST_F(OplogFetcherTest, MetadataObjectIsEmptyUnderProtocolVersion0) {
diff --git a/src/mongo/db/repl/replication_coordinator.h b/src/mongo/db/repl/replication_coordinator.h
index c33582a0aba..79deadb3bf9 100644
--- a/src/mongo/db/repl/replication_coordinator.h
+++ b/src/mongo/db/repl/replication_coordinator.h
@@ -57,9 +57,9 @@ struct ConnectionPoolStats;
 
 namespace rpc {
 
+class OplogQueryMetadata;
 class ReplSetMetadata;
 class RequestInterface;
-class ReplSetMetadata;
 
 }  // namespace rpc
 
@@ -689,9 +689,11 @@ public:
                                               ReplSetRequestVotesResponse* response) = 0;
 
     /**
-     * Prepares a metadata object describing the current term, primary, and lastOp information.
+     * Prepares a metadata object with the ReplSetMetadata and the OplogQueryMetadata depending
+     * on what has been requested.
      */
-    virtual void prepareReplMetadata(const OpTime& lastOpTimeFromClient,
+    virtual void prepareReplMetadata(const BSONObj& metadataRequestObj,
+                                     const OpTime& lastOpTimeFromClient,
                                      BSONObjBuilder* builder) const = 0;
 
     /**
diff --git a/src/mongo/db/repl/replication_coordinator_impl.cpp b/src/mongo/db/repl/replication_coordinator_impl.cpp
index a6e427ae879..66db01ccfe9 100644
--- a/src/mongo/db/repl/replication_coordinator_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl.cpp
@@ -73,6 +73,7 @@
 #include "mongo/db/write_concern.h"
 #include "mongo/db/write_concern_options.h"
 #include "mongo/executor/connection_pool_stats.h"
+#include "mongo/rpc/metadata/oplog_query_metadata.h"
 #include "mongo/rpc/metadata/repl_set_metadata.h"
 #include "mongo/rpc/metadata/server_selection_metadata.h"
 #include "mongo/rpc/request_interface.h"
@@ -385,6 +386,10 @@ Date_t ReplicationCoordinatorImpl::getPriorityTakeover_forTest() const {
 
 OpTime ReplicationCoordinatorImpl::getCurrentCommittedSnapshotOpTime() const {
     stdx::lock_guard<stdx::mutex> lk(_mutex);
+    return _getCurrentCommittedSnapshotOpTime_inlock();
+}
+
+OpTime ReplicationCoordinatorImpl::_getCurrentCommittedSnapshotOpTime_inlock() const {
     if (_currentCommittedSnapshot) {
         return _currentCommittedSnapshot->opTime;
     }
@@ -2015,7 +2020,9 @@ StatusWith<BSONObj> ReplicationCoordinatorImpl::prepareReplSetUpdatePositionComm
 
     // Add metadata to command. Old style parsing logic will reject the metadata.
     if (commandStyle == ReplSetUpdatePositionCommandStyle::kNewStyle) {
-        prepareReplMetadata(OpTime(), &cmdBuilder);
+        stdx::lock_guard<stdx::mutex> topoLock(_topoMutex);
+        stdx::lock_guard<stdx::mutex> lock(_mutex);
+        _prepareReplSetMetadata_inlock(OpTime(), &cmdBuilder);
     }
     return cmdBuilder.obj();
 }
@@ -3250,14 +3257,41 @@ Status ReplicationCoordinatorImpl::processReplSetRequestVotes(
     return Status::OK();
 }
 
-void ReplicationCoordinatorImpl::prepareReplMetadata(const OpTime& lastOpTimeFromClient,
+void ReplicationCoordinatorImpl::prepareReplMetadata(const BSONObj& metadataRequestObj,
+                                                     const OpTime& lastOpTimeFromClient,
                                                      BSONObjBuilder* builder) const {
-    rpc::ReplSetMetadata metadata;
+
+    bool hasReplSetMetadata = metadataRequestObj.hasField(rpc::kReplSetMetadataFieldName);
+    bool hasOplogQueryMetadata = metadataRequestObj.hasField(rpc::kOplogQueryMetadataFieldName);
+    // Don't take any locks if we do not need to.
+    if (!hasReplSetMetadata && !hasOplogQueryMetadata) {
+        return;
+    }
+
     LockGuard topoLock(_topoMutex);
+    LockGuard lock(_mutex);
+
+    if (hasReplSetMetadata) {
+        _prepareReplSetMetadata_inlock(lastOpTimeFromClient, builder);
+    }
+
+    if (hasOplogQueryMetadata) {
+        _prepareOplogQueryMetadata_inlock(builder);
+    }
+}
+
+void ReplicationCoordinatorImpl::_prepareReplSetMetadata_inlock(const OpTime& lastOpTimeFromClient,
+                                                                BSONObjBuilder* builder) const {
+    OpTime lastVisibleOpTime =
+        std::max(lastOpTimeFromClient, _getCurrentCommittedSnapshotOpTime_inlock());
+    auto metadata = _topCoord->prepareReplSetMetadata(lastVisibleOpTime, _lastCommittedOpTime);
+    metadata.writeToMetadata(builder);
+}
 
-    OpTime lastReadableOpTime = getCurrentCommittedSnapshotOpTime();
-    OpTime lastVisibleOpTime = std::max(lastOpTimeFromClient, lastReadableOpTime);
-    _topCoord->prepareReplMetadata(&metadata, lastVisibleOpTime, _lastCommittedOpTime);
+void ReplicationCoordinatorImpl::_prepareOplogQueryMetadata_inlock(BSONObjBuilder* builder) const {
+    OpTime lastAppliedOpTime = _getMyLastAppliedOpTime_inlock();
+    auto metadata =
+        _topCoord->prepareOplogQueryMetadata(_lastCommittedOpTime, lastAppliedOpTime, _rbid);
     metadata.writeToMetadata(builder);
 }
 
diff --git a/src/mongo/db/repl/replication_coordinator_impl.h b/src/mongo/db/repl/replication_coordinator_impl.h
index 9b7eb084d2e..b8f19b16271 100644
--- a/src/mongo/db/repl/replication_coordinator_impl.h
+++ b/src/mongo/db/repl/replication_coordinator_impl.h
@@ -65,6 +65,7 @@ struct ConnectionPoolStats;
 }  // namespace executor
 
 namespace rpc {
+class OplogQueryMetadata;
 class ReplSetMetadata;
 }  // namespace rpc
 
@@ -270,7 +271,8 @@ public:
                                               const ReplSetRequestVotesArgs& args,
                                               ReplSetRequestVotesResponse* response) override;
 
-    virtual void prepareReplMetadata(const OpTime& lastOpTimeFromClient,
+    virtual void prepareReplMetadata(const BSONObj& metadataRequestObj,
+                                     const OpTime& lastOpTimeFromClient,
                                      BSONObjBuilder* builder) const override;
 
     virtual Status processHeartbeatV1(const ReplSetHeartbeatArgsV1& args,
@@ -554,6 +556,11 @@ private:
     bool getWriteConcernMajorityShouldJournal_inlock() const;
 
     /**
+     * Returns the OpTime of the current committed snapshot, if one exists.
+     */
+    OpTime _getCurrentCommittedSnapshotOpTime_inlock() const;
+
+    /**
      * Helper method that removes entries from _slaveInfo if they correspond to a node
      * with a member ID that is not in the current replica set config.  Will always leave an
      * entry for ourself at the beginning of _slaveInfo, even if we aren't present in the
@@ -978,6 +985,17 @@ private:
                                                    bool advanceCommitPoint);
 
     /**
+     * Prepares a metadata object for ReplSetMetadata.
+     */
+    void _prepareReplSetMetadata_inlock(const OpTime& lastOpTimeFromClient,
+                                        BSONObjBuilder* builder) const;
+
+    /**
+     * Prepares a metadata object for OplogQueryMetadata.
+     */
+    void _prepareOplogQueryMetadata_inlock(BSONObjBuilder* builder) const;
+
+    /**
      * Blesses a snapshot to be used for new committed reads.
      */
     void _updateCommittedSnapshot_inlock(SnapshotInfo newCommittedSnapshot);
diff --git a/src/mongo/db/repl/replication_coordinator_impl_test.cpp b/src/mongo/db/repl/replication_coordinator_impl_test.cpp
index 757a422bf70..ceaae23fbea 100644
--- a/src/mongo/db/repl/replication_coordinator_impl_test.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl_test.cpp
@@ -59,6 +59,7 @@
 #include "mongo/db/service_context_noop.h"
 #include "mongo/db/write_concern_options.h"
 #include "mongo/executor/network_interface_mock.h"
+#include "mongo/rpc/metadata/oplog_query_metadata.h"
 #include "mongo/rpc/metadata/repl_set_metadata.h"
 #include "mongo/stdx/functional.h"
 #include "mongo/stdx/future.h"
@@ -4071,6 +4072,80 @@ TEST_F(ReplCoordTest,
     ASSERT_EQUALS(-1, getTopoCoord().getCurrentPrimaryIndex());
 }
 
+TEST_F(ReplCoordTest, PrepareOplogQueryMetadata) {
+    assertStartSuccess(BSON("_id"
+                            << "mySet"
+                            << "version"
+                            << 2
+                            << "members"
+                            << BSON_ARRAY(BSON("host"
+                                               << "node1:12345"
+                                               << "_id"
+                                               << 0)
+                                          << BSON("host"
+                                                  << "node2:12345"
+                                                  << "_id"
+                                                  << 1)
+                                          << BSON("host"
+                                                  << "node3:12345"
+                                                  << "_id"
+                                                  << 2))
+                            << "protocolVersion"
+                            << 1),
+                       HostAndPort("node1", 12345));
+    getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY);
+
+    // Update committed optime with ReplSetMetadata.
+    OpTime optime1{Timestamp(10, 0), 3};
+    OpTime optime2{Timestamp(11, 2), 5};
+
+    StatusWith<rpc::ReplSetMetadata> metadataToProcess = rpc::ReplSetMetadata::readFromMetadata(
+        BSON(rpc::kReplSetMetadataFieldName
+             << BSON("lastOpCommitted" << optime1.toBSON() << "lastOpVisible" << optime1.toBSON()
+                                       << "configVersion"
+                                       << 2
+                                       << "primaryIndex"
+                                       << 2
+                                       << "term"
+                                       << 3
+                                       << "syncSourceIndex"
+                                       << 1)));
+    getReplCoord()->processReplSetMetadata(metadataToProcess.getValue(), true);
+
+    getReplCoord()->setMyLastAppliedOpTime(optime2);
+
+    // Get current rbid to check against.
+    BSONObjBuilder result;
+    getReplCoord()->processReplSetGetRBID(&result);
+    int initialValue = result.obj()["rbid"].Int();
+
+    BSONObjBuilder metadataBob;
+    getReplCoord()->prepareReplMetadata(
+        BSON(rpc::kOplogQueryMetadataFieldName << 1 << rpc::kReplSetMetadataFieldName << 1),
+        OpTime(),
+        &metadataBob);
+
+    BSONObj metadata = metadataBob.done();
+    log() << metadata;
+
+    auto oqMetadata = rpc::OplogQueryMetadata::readFromMetadata(metadata);
+    ASSERT_OK(oqMetadata.getStatus());
+    ASSERT_EQ(oqMetadata.getValue().getLastOpCommitted(), optime1);
+    ASSERT_EQ(oqMetadata.getValue().getLastOpApplied(), optime2);
+    ASSERT_EQ(oqMetadata.getValue().getRBID(), initialValue);
+    ASSERT_EQ(oqMetadata.getValue().getSyncSourceIndex(), -1);
+    ASSERT_EQ(oqMetadata.getValue().getPrimaryIndex(), -1);
+
+    auto replMetadata = rpc::ReplSetMetadata::readFromMetadata(metadata);
+    ASSERT_OK(replMetadata.getStatus());
+    ASSERT_EQ(replMetadata.getValue().getLastOpCommitted(), optime1);
+    ASSERT_EQ(replMetadata.getValue().getLastOpVisible(), OpTime());
+    ASSERT_EQ(replMetadata.getValue().getConfigVersion(), 2);
+    ASSERT_EQ(replMetadata.getValue().getTerm(), 3);
+    ASSERT_EQ(replMetadata.getValue().getSyncSourceIndex(), -1);
+    ASSERT_EQ(replMetadata.getValue().getPrimaryIndex(), -1);
+}
+
 TEST_F(ReplCoordTest, TermAndLastCommittedOpTimeUpdatedFromHeartbeatWhenArbiter) {
     // Ensure that the metadata is processed if it is contained in a heartbeat response.
     assertStartSuccess(BSON("_id"
diff --git a/src/mongo/db/repl/replication_coordinator_mock.cpp b/src/mongo/db/repl/replication_coordinator_mock.cpp
index ee2c819bc4d..9663600063c 100644
--- a/src/mongo/db/repl/replication_coordinator_mock.cpp
+++ b/src/mongo/db/repl/replication_coordinator_mock.cpp
@@ -397,7 +397,8 @@ Status ReplicationCoordinatorMock::processReplSetRequestVotes(
     return Status::OK();
 }
 
-void ReplicationCoordinatorMock::prepareReplMetadata(const OpTime& lastOpTimeFromClient,
+void ReplicationCoordinatorMock::prepareReplMetadata(const BSONObj& metadataRequestObj,
+                                                     const OpTime& lastOpTimeFromClient,
                                                      BSONObjBuilder* builder) const {}
 
 Status ReplicationCoordinatorMock::processHeartbeatV1(const ReplSetHeartbeatArgsV1& args,
diff --git a/src/mongo/db/repl/replication_coordinator_mock.h b/src/mongo/db/repl/replication_coordinator_mock.h
index 67d6a555274..d2b00cc206e 100644
--- a/src/mongo/db/repl/replication_coordinator_mock.h
+++ b/src/mongo/db/repl/replication_coordinator_mock.h
@@ -221,7 +221,8 @@ public:
                                               const ReplSetRequestVotesArgs& args,
                                               ReplSetRequestVotesResponse* response);
 
-    void prepareReplMetadata(const OpTime& lastOpTimeFromClient,
+    void prepareReplMetadata(const BSONObj& metadataRequestObj,
+                             const OpTime& lastOpTimeFromClient,
                              BSONObjBuilder* builder) const override;
 
     virtual Status processHeartbeatV1(const ReplSetHeartbeatArgsV1& args,
diff --git a/src/mongo/db/repl/topology_coordinator.h b/src/mongo/db/repl/topology_coordinator.h
index 26462a99c68..7dcf76164ec 100644
--- a/src/mongo/db/repl/topology_coordinator.h
+++ b/src/mongo/db/repl/topology_coordinator.h
@@ -435,11 +435,19 @@ public:
     virtual void setMyHeartbeatMessage(const Date_t now, const std::string& s) = 0;
 
     /**
-     * Prepares a BSONObj describing the current term, primary, and lastOp information.
+     * Prepares a ReplSetMetadata object describing the current term, primary, and lastOp
+     * information.
      */
-    virtual void prepareReplMetadata(rpc::ReplSetMetadata* metadata,
-                                     const OpTime& lastVisibleOpTime,
-                                     const OpTime& lastCommittedOpTime) const = 0;
+    virtual rpc::ReplSetMetadata prepareReplSetMetadata(
+        const OpTime& lastVisibleOpTime, const OpTime& lastCommittedOpTime) const = 0;
+
+    /**
+     * Prepares an OplogQueryMetadata object describing the current sync source, rbid, primary,
+     * lastOpApplied, and lastOpCommitted.
+     */
+    virtual rpc::OplogQueryMetadata prepareOplogQueryMetadata(const OpTime& lastCommittedOpTime,
+                                                              const OpTime& lastAppliedOpTime,
+                                                              int rbid) const = 0;
 
     /**
      * Writes into 'output' all the information needed to generate a summary of the current
diff --git a/src/mongo/db/repl/topology_coordinator_impl.cpp b/src/mongo/db/repl/topology_coordinator_impl.cpp
index a96790c41a5..1f6d11a86bb 100644
--- a/src/mongo/db/repl/topology_coordinator_impl.cpp
+++ b/src/mongo/db/repl/topology_coordinator_impl.cpp
@@ -48,6 +48,7 @@
 #include "mongo/db/repl/replication_executor.h"
 #include "mongo/db/repl/rslog.h"
 #include "mongo/db/server_parameters.h"
+#include "mongo/rpc/metadata/oplog_query_metadata.h"
 #include "mongo/rpc/metadata/repl_set_metadata.h"
 #include "mongo/util/fail_point_service.h"
 #include "mongo/util/hex.h"
@@ -2511,17 +2512,24 @@ bool TopologyCoordinatorImpl::shouldChangeSyncSource(const HostAndPort& currentS
     return false;
 }
 
-void TopologyCoordinatorImpl::prepareReplMetadata(rpc::ReplSetMetadata* metadata,
-                                                  const OpTime& lastVisibleOpTime,
-                                                  const OpTime& lastCommittedOpTime) const {
-    *metadata =
-        rpc::ReplSetMetadata(_term,
-                             lastCommittedOpTime,
-                             lastVisibleOpTime,
-                             _rsConfig.getConfigVersion(),
-                             _rsConfig.getReplicaSetId(),
-                             _currentPrimaryIndex,
-                             _rsConfig.findMemberIndexByHostAndPort(getSyncSourceAddress()));
+rpc::ReplSetMetadata TopologyCoordinatorImpl::prepareReplSetMetadata(
+    const OpTime& lastVisibleOpTime, const OpTime& lastCommittedOpTime) const {
+    return rpc::ReplSetMetadata(_term,
+                                lastCommittedOpTime,
+                                lastVisibleOpTime,
+                                _rsConfig.getConfigVersion(),
+                                _rsConfig.getReplicaSetId(),
+                                _currentPrimaryIndex,
+                                _rsConfig.findMemberIndexByHostAndPort(getSyncSourceAddress()));
+}
+
+rpc::OplogQueryMetadata TopologyCoordinatorImpl::prepareOplogQueryMetadata(
+    const OpTime& lastCommittedOpTime, const OpTime& lastAppliedOpTime, int rbid) const {
+    return rpc::OplogQueryMetadata(lastCommittedOpTime,
+                                   lastAppliedOpTime,
+                                   rbid,
+                                   _currentPrimaryIndex,
+                                   _rsConfig.findMemberIndexByHostAndPort(getSyncSourceAddress()));
 }
 
 void TopologyCoordinatorImpl::summarizeAsHtml(ReplSetHtmlSummary* output) {
diff --git a/src/mongo/db/repl/topology_coordinator_impl.h b/src/mongo/db/repl/topology_coordinator_impl.h
index ec2b02ebccd..57dabbf6ad9 100644
--- a/src/mongo/db/repl/topology_coordinator_impl.h
+++ b/src/mongo/db/repl/topology_coordinator_impl.h
@@ -223,9 +223,11 @@ public:
                           const OpTime& lastOpCommitted);
     virtual bool stepDownIfPending();
     virtual Date_t getStepDownTime() const;
-    virtual void prepareReplMetadata(rpc::ReplSetMetadata* metadata,
-                                     const OpTime& lastVisibleOpTime,
-                                     const OpTime& lastCommitttedOpTime) const;
+    virtual rpc::ReplSetMetadata prepareReplSetMetadata(const OpTime& lastVisibleOpTime,
+                                                        const OpTime& lastCommitttedOpTime) const;
+    virtual rpc::OplogQueryMetadata prepareOplogQueryMetadata(const OpTime& lastCommittedOpTime,
+                                                              const OpTime& lastAppliedOpTime,
+                                                              int rbid) const;
     virtual void processReplSetRequestVotes(const ReplSetRequestVotesArgs& args,
                                             ReplSetRequestVotesResponse* response,
                                             const OpTime& lastAppliedOpTime);