SERVER-27149 Don't sync from nodes in an older term.

(cherry picked from commit 138402742f13b1cf85b021966eb27f2e33667cca)

15 files changed, 170 insertions, 122 deletions

diff --git a/src/mongo/db/repl/data_replicator.cpp b/src/mongo/db/repl/data_replicator.cpp
index 7eb266c2b9c..7761e56b076 100644
--- a/src/mongo/db/repl/data_replicator.cpp
+++ b/src/mongo/db/repl/data_replicator.cpp
@@ -1207,8 +1207,7 @@ void DataReplicator::_setState_inlock(const DataReplicatorState& newState) {
 }
 
 StatusWith<HostAndPort> DataReplicator::_chooseSyncSource_inlock() {
-    auto syncSource =
-        _opts.syncSourceSelector->chooseNewSyncSource(_lastFetched.opTime.getTimestamp());
+    auto syncSource = _opts.syncSourceSelector->chooseNewSyncSource(_lastFetched.opTime);
     if (syncSource.empty()) {
         return Status{ErrorCodes::InvalidSyncSource,
                       str::stream() << "No valid sync source available. Our last fetched optime: "
diff --git a/src/mongo/db/repl/data_replicator_test.cpp b/src/mongo/db/repl/data_replicator_test.cpp
index 2aaeb5a6074..3a451783597 100644
--- a/src/mongo/db/repl/data_replicator_test.cpp
+++ b/src/mongo/db/repl/data_replicator_test.cpp
@@ -85,7 +85,7 @@ class SyncSourceSelectorMock : public SyncSourceSelector {
 public:
     SyncSourceSelectorMock(const HostAndPort& syncSource) : _syncSource(syncSource) {}
     void clearSyncSourceBlacklist() override {}
-    HostAndPort chooseNewSyncSource(const Timestamp& ts) override {
+    HostAndPort chooseNewSyncSource(const OpTime& ot) override {
         HostAndPort result = _syncSource;
         return result;
     }
@@ -120,8 +120,8 @@ public:
     void clearSyncSourceBlacklist() override {
         _syncSourceSelector->clearSyncSourceBlacklist();
     }
-    HostAndPort chooseNewSyncSource(const Timestamp& ts) override {
-        return _syncSourceSelector->chooseNewSyncSource(ts);
+    HostAndPort chooseNewSyncSource(const OpTime& ot) override {
+        return _syncSourceSelector->chooseNewSyncSource(ot);
     }
     void blacklistSyncSource(const HostAndPort& host, Date_t until) override {
         _syncSourceSelector->blacklistSyncSource(host, until);
diff --git a/src/mongo/db/repl/oplogreader.cpp b/src/mongo/db/repl/oplogreader.cpp
index b7e6a06c7d2..92bc6648b8b 100644
--- a/src/mongo/db/repl/oplogreader.cpp
+++ b/src/mongo/db/repl/oplogreader.cpp
@@ -164,7 +164,7 @@ void OplogReader::connectToSyncSource(OperationContext* txn,
     invariant(conn() == NULL);
 
     while (true) {
-        HostAndPort candidate = replCoord->chooseNewSyncSource(lastOpTimeFetched.getTimestamp());
+        HostAndPort candidate = replCoord->chooseNewSyncSource(lastOpTimeFetched);
 
         if (candidate.empty()) {
             if (oldestOpTimeSeen == sentinel) {
diff --git a/src/mongo/db/repl/replication_coordinator_impl.cpp b/src/mongo/db/repl/replication_coordinator_impl.cpp
index 851c91dac40..699bb2636ac 100644
--- a/src/mongo/db/repl/replication_coordinator_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl.cpp
@@ -3037,15 +3037,15 @@ bool ReplicationCoordinatorImpl::isReplEnabled() const {
     return getReplicationMode() != modeNone;
 }
 
-HostAndPort ReplicationCoordinatorImpl::chooseNewSyncSource(const Timestamp& lastTimestampFetched) {
+HostAndPort ReplicationCoordinatorImpl::chooseNewSyncSource(const OpTime& lastOpTimeFetched) {
     LockGuard topoLock(_topoMutex);
 
     HostAndPort oldSyncSource = _topCoord->getSyncSourceAddress();
     auto chainingPreference = isCatchingUp()
         ? TopologyCoordinator::ChainingPreference::kAllowChaining
         : TopologyCoordinator::ChainingPreference::kUseConfiguration;
-    HostAndPort newSyncSource = _topCoord->chooseNewSyncSource(
-        _replExecutor.now(), lastTimestampFetched, chainingPreference);
+    HostAndPort newSyncSource =
+        _topCoord->chooseNewSyncSource(_replExecutor.now(), lastOpTimeFetched, chainingPreference);
 
     stdx::lock_guard<stdx::mutex> lock(_mutex);
     // If we lost our sync source, schedule new heartbeats immediately to update our knowledge
diff --git a/src/mongo/db/repl/replication_coordinator_impl.h b/src/mongo/db/repl/replication_coordinator_impl.h
index 14b9571b7f4..bdbec4bac08 100644
--- a/src/mongo/db/repl/replication_coordinator_impl.h
+++ b/src/mongo/db/repl/replication_coordinator_impl.h
@@ -261,7 +261,7 @@ public:
 
     virtual bool isReplEnabled() const override;
 
-    virtual HostAndPort chooseNewSyncSource(const Timestamp& lastTimestampFetched) override;
+    virtual HostAndPort chooseNewSyncSource(const OpTime& lastOpTimeFetched) override;
 
     virtual void blacklistSyncSource(const HostAndPort& host, Date_t until) override;
 
diff --git a/src/mongo/db/repl/replication_coordinator_mock.cpp b/src/mongo/db/repl/replication_coordinator_mock.cpp
index 22d2eed1f0d..d6e4679e78c 100644
--- a/src/mongo/db/repl/replication_coordinator_mock.cpp
+++ b/src/mongo/db/repl/replication_coordinator_mock.cpp
@@ -370,7 +370,7 @@ Status ReplicationCoordinatorMock::checkReplEnabledForCommand(BSONObjBuilder* re
     return Status::OK();
 }
 
-HostAndPort ReplicationCoordinatorMock::chooseNewSyncSource(const Timestamp& lastTimestampFetched) {
+HostAndPort ReplicationCoordinatorMock::chooseNewSyncSource(const OpTime& lastOpTimeFetched) {
     return HostAndPort();
 }
 
diff --git a/src/mongo/db/repl/replication_coordinator_mock.h b/src/mongo/db/repl/replication_coordinator_mock.h
index 0a61d010a1a..d21c3c8e40d 100644
--- a/src/mongo/db/repl/replication_coordinator_mock.h
+++ b/src/mongo/db/repl/replication_coordinator_mock.h
@@ -205,7 +205,7 @@ public:
 
     virtual Status checkReplEnabledForCommand(BSONObjBuilder* result);
 
-    virtual HostAndPort chooseNewSyncSource(const Timestamp& lastTimestampFetched);
+    virtual HostAndPort chooseNewSyncSource(const OpTime& lastOpTimeFetched);
 
     virtual void blacklistSyncSource(const HostAndPort& host, Date_t until);
 
diff --git a/src/mongo/db/repl/sync_source_resolver.cpp b/src/mongo/db/repl/sync_source_resolver.cpp
index dced97cef3a..39ec824ebac 100644
--- a/src/mongo/db/repl/sync_source_resolver.cpp
+++ b/src/mongo/db/repl/sync_source_resolver.cpp
@@ -144,7 +144,7 @@ bool SyncSourceResolver::_isShuttingDown() const {
 StatusWith<HostAndPort> SyncSourceResolver::_chooseNewSyncSource() {
     HostAndPort candidate;
     try {
-        candidate = _syncSourceSelector->chooseNewSyncSource(_lastOpTimeFetched.getTimestamp());
+        candidate = _syncSourceSelector->chooseNewSyncSource(_lastOpTimeFetched);
     } catch (...) {
         return exceptionToStatus();
     }
diff --git a/src/mongo/db/repl/sync_source_resolver_test.cpp b/src/mongo/db/repl/sync_source_resolver_test.cpp
index 4e94057031d..1022ef54e26 100644
--- a/src/mongo/db/repl/sync_source_resolver_test.cpp
+++ b/src/mongo/db/repl/sync_source_resolver_test.cpp
@@ -70,9 +70,9 @@ private:
 class SyncSourceSelectorMock : public SyncSourceSelector {
 public:
     void clearSyncSourceBlacklist() override {}
-    HostAndPort chooseNewSyncSource(const Timestamp& ts) override {
+    HostAndPort chooseNewSyncSource(const OpTime& ot) override {
         chooseNewSyncSourceHook();
-        lastTimestampFetched = ts;
+        lastOpTimeFetched = ot;
         return syncSource;
     }
     void blacklistSyncSource(const HostAndPort& host, Date_t until) override {
@@ -84,7 +84,7 @@ public:
     }
 
     HostAndPort syncSource = HostAndPort("host1", 1234);
-    Timestamp lastTimestampFetched;
+    OpTime lastOpTimeFetched;
     stdx::function<void()> chooseNewSyncSourceHook = []() {};
 
     HostAndPort blacklistHost;
@@ -264,7 +264,7 @@ TEST_F(SyncSourceResolverTest,
     // Resolver invokes callback with empty host and becomes inactive immediately.
     ASSERT_FALSE(_resolver->isActive());
     ASSERT_EQUALS(HostAndPort(), unittest::assertGet(_response.syncSourceStatus));
-    ASSERT_EQUALS(lastOpTimeFetched.getTimestamp(), _selector->lastTimestampFetched);
+    ASSERT_EQUALS(lastOpTimeFetched, _selector->lastOpTimeFetched);
 
     // Cannot restart a completed resolver.
     ASSERT_EQUALS(ErrorCodes::ShutdownInProgress, _resolver->startup());
diff --git a/src/mongo/db/repl/sync_source_selector.h b/src/mongo/db/repl/sync_source_selector.h
index 131c3846e24..36cd7df3bf4 100644
--- a/src/mongo/db/repl/sync_source_selector.h
+++ b/src/mongo/db/repl/sync_source_selector.h
@@ -64,7 +64,7 @@ public:
     /**
      * Chooses a viable sync source, or, if none available, returns empty HostAndPort.
      */
-    virtual HostAndPort chooseNewSyncSource(const Timestamp& lastTimestampFetched) = 0;
+    virtual HostAndPort chooseNewSyncSource(const OpTime& lastOpTimeFetched) = 0;
 
     /**
      * Blacklists choosing 'host' as a sync source until time 'until'.
diff --git a/src/mongo/db/repl/topology_coordinator.h b/src/mongo/db/repl/topology_coordinator.h
index 3dbd739f9cd..8fe8fe13c34 100644
--- a/src/mongo/db/repl/topology_coordinator.h
+++ b/src/mongo/db/repl/topology_coordinator.h
@@ -138,7 +138,7 @@ public:
      * Chooses and sets a new sync source, based on our current knowledge of the world.
      */
     virtual HostAndPort chooseNewSyncSource(Date_t now,
-                                            const Timestamp& lastTimestampFetched,
+                                            const OpTime& lastOpTimeFetched,
                                             ChainingPreference chainingPreference) = 0;
 
     /**
diff --git a/src/mongo/db/repl/topology_coordinator_impl.cpp b/src/mongo/db/repl/topology_coordinator_impl.cpp
index 8062a122e5c..bc7029a7a4c 100644
--- a/src/mongo/db/repl/topology_coordinator_impl.cpp
+++ b/src/mongo/db/repl/topology_coordinator_impl.cpp
@@ -154,7 +154,7 @@ HostAndPort TopologyCoordinatorImpl::getSyncSourceAddress() const {
 }
 
 HostAndPort TopologyCoordinatorImpl::chooseNewSyncSource(Date_t now,
-                                                         const Timestamp& lastTimestampFetched,
+                                                         const OpTime& lastOpTimeFetched,
                                                          ChainingPreference chainingPreference) {
     // If we are not a member of the current replica set configuration, no sync source is valid.
     if (_selfIndex == -1) {
@@ -305,12 +305,12 @@ HostAndPort TopologyCoordinatorImpl::chooseNewSyncSource(Date_t now,
                 }
             }
             // only consider candidates that are ahead of where we are
-            if (it->getAppliedOpTime().getTimestamp() <= lastTimestampFetched) {
+            if (it->getAppliedOpTime() <= lastOpTimeFetched) {
                 LOG(1) << "Cannot select sync source equal to or behind our last fetched optime. "
-                       << "My last fetched oplog timestamp: " << lastTimestampFetched.toBSON()
-                       << ", latest oplog timestamp of sync candidate "
+                       << "My last fetched oplog optime: " << lastOpTimeFetched.toBSON()
+                       << ", latest oplog optime of sync candidate "
                        << itMemberConfig.getHostAndPort() << ": "
-                       << it->getAppliedOpTime().getTimestamp().toBSON();
+                       << it->getAppliedOpTime().toBSON();
                 continue;
             }
             // Candidate cannot be more latent than anything we've already considered.
diff --git a/src/mongo/db/repl/topology_coordinator_impl.h b/src/mongo/db/repl/topology_coordinator_impl.h
index 9d57ffe0812..aac4c201e5b 100644
--- a/src/mongo/db/repl/topology_coordinator_impl.h
+++ b/src/mongo/db/repl/topology_coordinator_impl.h
@@ -151,8 +151,8 @@ public:
     virtual UpdateTermResult updateTerm(long long term, Date_t now);
     virtual void setForceSyncSourceIndex(int index);
     virtual HostAndPort chooseNewSyncSource(Date_t now,
-                                            const Timestamp& lastTimestampFetched,
-                                            ChainingPreference chainingPreference);
+                                            const OpTime& lastOpTimeFetched,
+                                            ChainingPreference chainingPreference) override;
     virtual void blacklistSyncSource(const HostAndPort& host, Date_t until);
     virtual void unblacklistSyncSource(const HostAndPort& host, Date_t now);
     virtual void clearSyncSourceBlacklist();
diff --git a/src/mongo/db/repl/topology_coordinator_impl_test.cpp b/src/mongo/db/repl/topology_coordinator_impl_test.cpp
index 52515127657..d0281db8217 100644
--- a/src/mongo/db/repl/topology_coordinator_impl_test.cpp
+++ b/src/mongo/db/repl/topology_coordinator_impl_test.cpp
@@ -240,7 +240,7 @@ private:
 TEST_F(TopoCoordTest, NodeReturnsSecondaryWithMostRecentDataAsSyncSource) {
     // if we do not have an index in the config, we should get an empty syncsource
     HostAndPort newSyncSource = getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_TRUE(newSyncSource.empty());
 
     updateConfig(BSON("_id"
@@ -267,7 +267,7 @@ TEST_F(TopoCoordTest, NodeReturnsSecondaryWithMostRecentDataAsSyncSource) {
 
     // Fail due to insufficient number of pings
     newSyncSource = getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(getTopoCoord().getSyncSourceAddress(), newSyncSource);
     ASSERT(getTopoCoord().getSyncSourceAddress().empty());
 
@@ -278,7 +278,7 @@ TEST_F(TopoCoordTest, NodeReturnsSecondaryWithMostRecentDataAsSyncSource) {
 
     // Should choose h2, since it is furthest ahead
     newSyncSource = getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(getTopoCoord().getSyncSourceAddress(), newSyncSource);
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
@@ -286,34 +286,34 @@ TEST_F(TopoCoordTest, NodeReturnsSecondaryWithMostRecentDataAsSyncSource) {
     heartbeatFromMember(
         HostAndPort("h3"), "rs0", MemberState::RS_SECONDARY, OpTime(Timestamp(2, 0), 0));
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
 
     // h3 becomes an invalid candidate for sync source; should choose h2 again
     heartbeatFromMember(
         HostAndPort("h3"), "rs0", MemberState::RS_RECOVERING, OpTime(Timestamp(2, 0), 0));
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
     // h3 back in SECONDARY and ahead
     heartbeatFromMember(
         HostAndPort("h3"), "rs0", MemberState::RS_SECONDARY, OpTime(Timestamp(2, 0), 0));
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
 
     // h3 goes down
     receiveDownHeartbeat(HostAndPort("h3"), "rs0", OpTime());
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
     // h3 back up and ahead
     heartbeatFromMember(
         HostAndPort("h3"), "rs0", MemberState::RS_SECONDARY, OpTime(Timestamp(2, 0), 0));
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
 }
 
@@ -358,7 +358,7 @@ TEST_F(TopoCoordTest, NodeReturnsClosestValidSyncSourceAsSyncSource) {
                  0);
 
     setSelfMemberState(MemberState::RS_SECONDARY);
-    Timestamp lastOpTimeWeApplied = Timestamp(100, 0);
+    OpTime lastOpTimeWeApplied = OpTime(Timestamp(100, 0), 0);
 
     heartbeatFromMember(HostAndPort("h1"),
                         "rs0",
@@ -533,7 +533,7 @@ TEST_F(TopoCoordTest, ChooseOnlyPrimaryAsSyncSourceWhenChainingIsDisallowed) {
     ASSERT_EQUALS(
         HostAndPort(),
         getTopoCoord().chooseNewSyncSource(
-            now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
+            now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
     ASSERT(getTopoCoord().getSyncSourceAddress().empty());
 
     // Add primary
@@ -548,18 +548,20 @@ TEST_F(TopoCoordTest, ChooseOnlyPrimaryAsSyncSourceWhenChainingIsDisallowed) {
     // h3 is primary and should be chosen as the sync source when we are not in catch-up mode,
     // despite being further away than h2 and the primary (h3) being behind our most recently
     // applied optime.
-    ASSERT_EQUALS(
-        HostAndPort("h3"),
-        getTopoCoord().chooseNewSyncSource(
-            now()++, Timestamp(10, 0), TopologyCoordinator::ChainingPreference::kUseConfiguration));
+    ASSERT_EQUALS(HostAndPort("h3"),
+                  getTopoCoord().chooseNewSyncSource(
+                      now()++,
+                      OpTime(Timestamp(10, 0), 0),
+                      TopologyCoordinator::ChainingPreference::kUseConfiguration));
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
 
     // When we are in catch-up mode, the chainingAllowed setting is ignored. h2 should be chosen as
     // the sync source.
-    ASSERT_EQUALS(
-        HostAndPort("h2"),
-        getTopoCoord().chooseNewSyncSource(
-            now()++, Timestamp(10, 0), TopologyCoordinator::ChainingPreference::kAllowChaining));
+    ASSERT_EQUALS(HostAndPort("h2"),
+                  getTopoCoord().chooseNewSyncSource(
+                      now()++,
+                      OpTime(Timestamp(10, 0), 0),
+                      TopologyCoordinator::ChainingPreference::kAllowChaining));
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
     // Become primary: should not choose self as sync source.
@@ -573,7 +575,7 @@ TEST_F(TopoCoordTest, ChooseOnlyPrimaryAsSyncSourceWhenChainingIsDisallowed) {
     ASSERT_EQUALS(
         HostAndPort(),
         getTopoCoord().chooseNewSyncSource(
-            now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
+            now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
     ASSERT(getTopoCoord().getSyncSourceAddress().empty());
 }
 
@@ -589,7 +591,7 @@ TEST_F(TopoCoordTest, ChooseOnlyVotersAsSyncSourceWhenNodeIsAVoter) {
 
     HostAndPort h2("h2"), h3("h3");
     Timestamp t1(1, 0), t5(5, 0), t10(10, 0);
-    OpTime ot1(t1, 0), ot5(t5, 0);
+    OpTime ot1(t1, 0), ot5(t5, 0), ot10(t10, 0);
     Milliseconds hbRTT100(100), hbRTT300(300);
 
     // Two rounds of heartbeat pings from each member.
@@ -600,18 +602,18 @@ TEST_F(TopoCoordTest, ChooseOnlyVotersAsSyncSourceWhenNodeIsAVoter) {
 
     // Should choose h3 as it is a voter
     auto newSource = getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(h3, newSource);
 
     // Can't choose h2 as it is not a voter
     newSource = getTopoCoord().chooseNewSyncSource(
-        now()++, t10, TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, ot10, TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort(), newSource);
 
     // Should choose h3 as it is a voter, and ahead
     heartbeatFromMember(h3, "rs0", MemberState::RS_SECONDARY, ot5, hbRTT300);
     newSource = getTopoCoord().chooseNewSyncSource(
-        now()++, t1, TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, ot1, TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(h3, newSource);
 }
 
@@ -657,7 +659,7 @@ TEST_F(TopoCoordTest, ChooseSameSyncSourceEvenWhenPrimary) {
     ASSERT_EQUALS(
         HostAndPort("h2"),
         getTopoCoord().chooseNewSyncSource(
-            now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
+            now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
     // Become primary
@@ -668,7 +670,7 @@ TEST_F(TopoCoordTest, ChooseSameSyncSourceEvenWhenPrimary) {
     ASSERT_EQUALS(
         HostAndPort("h2"),
         getTopoCoord().chooseNewSyncSource(
-            now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
+            now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 }
 
@@ -712,7 +714,7 @@ TEST_F(TopoCoordTest, ChooseRequestedSyncSourceOnlyTheFirstTimeAfterTheSyncSourc
 
     // force should overrule other defaults
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
     getTopoCoord().setForceSyncSourceIndex(1);
     // force should cause shouldChangeSyncSource() to return true
@@ -722,12 +724,12 @@ TEST_F(TopoCoordTest, ChooseRequestedSyncSourceOnlyTheFirstTimeAfterTheSyncSourc
     ASSERT_TRUE(
         getTopoCoord().shouldChangeSyncSource(HostAndPort("h3"), OpTime(), makeMetadata(), now()));
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
     // force should only work for one call to chooseNewSyncSource
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
 }
 
@@ -770,19 +772,19 @@ TEST_F(TopoCoordTest, NodeDoesNotChooseBlacklistedSyncSourceUntilBlacklistingExp
                         Milliseconds(100));
 
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
 
     Date_t expireTime = Date_t::fromMillisSinceEpoch(1000);
     getTopoCoord().blacklistSyncSource(HostAndPort("h3"), expireTime);
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     // Should choose second best choice now that h3 is blacklisted.
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
     // After time has passed, should go back to original sync source
     getTopoCoord().chooseNewSyncSource(
-        expireTime, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        expireTime, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
 }
 
@@ -828,19 +830,19 @@ TEST_F(TopoCoordTest, ChooseNoSyncSourceWhenPrimaryIsBlacklistedAndChainingIsDis
                         Milliseconds(100));
 
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
     Date_t expireTime = Date_t::fromMillisSinceEpoch(1000);
     getTopoCoord().blacklistSyncSource(HostAndPort("h2"), expireTime);
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     // Can't choose any sync source now.
     ASSERT(getTopoCoord().getSyncSourceAddress().empty());
 
     // After time has passed, should go back to the primary
     getTopoCoord().chooseNewSyncSource(
-        expireTime, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        expireTime, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 }
 
@@ -885,7 +887,7 @@ TEST_F(TopoCoordTest, NodeChangesToRecoveringWhenOnlyUnauthorizedNodesAreUp) {
     ASSERT_EQUALS(
         HostAndPort("h3"),
         getTopoCoord().chooseNewSyncSource(
-            now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
+            now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
     ASSERT_EQUALS(MemberState::RS_SECONDARY, getTopoCoord().getMemberState().s);
     // Good state setup done
 
@@ -894,7 +896,7 @@ TEST_F(TopoCoordTest, NodeChangesToRecoveringWhenOnlyUnauthorizedNodesAreUp) {
     receiveDownHeartbeat(HostAndPort("h3"), "rs0", OpTime(), ErrorCodes::NetworkTimeout);
     ASSERT_TRUE(getTopoCoord()
                     .chooseNewSyncSource(now()++,
-                                         Timestamp(),
+                                         OpTime(),
                                          TopologyCoordinator::ChainingPreference::kUseConfiguration)
                     .empty());
     ASSERT_EQUALS(MemberState::RS_SECONDARY, getTopoCoord().getMemberState().s);
@@ -904,7 +906,7 @@ TEST_F(TopoCoordTest, NodeChangesToRecoveringWhenOnlyUnauthorizedNodesAreUp) {
     receiveDownHeartbeat(HostAndPort("h3"), "rs0", OpTime(), ErrorCodes::Unauthorized);
     ASSERT_TRUE(getTopoCoord()
                     .chooseNewSyncSource(now()++,
-                                         Timestamp(),
+                                         OpTime(),
                                          TopologyCoordinator::ChainingPreference::kUseConfiguration)
                     .empty());
     ASSERT_EQUALS(MemberState::RS_RECOVERING, getTopoCoord().getMemberState().s);
@@ -1280,9 +1282,8 @@ TEST_F(TopoCoordTest, ChooseRequestedNodeWhenSyncFromRequestsAStaleNode) {
     ASSERT_OK(result);
     ASSERT_EQUALS("requested member \"h5:27017\" is more than 10 seconds behind us",
                   response.obj()["warning"].String());
-    getTopoCoord().chooseNewSyncSource(now()++,
-                                       ourOpTime.getTimestamp(),
-                                       TopologyCoordinator::ChainingPreference::kUseConfiguration);
+    getTopoCoord().chooseNewSyncSource(
+        now()++, ourOpTime, TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h5"), getTopoCoord().getSyncSourceAddress());
 }
 
@@ -1329,9 +1330,8 @@ TEST_F(TopoCoordTest, ChooseRequestedNodeWhenSyncFromRequestsAValidNode) {
     ASSERT_OK(result);
     BSONObj responseObj = response.obj();
     ASSERT_FALSE(responseObj.hasField("warning"));
-    getTopoCoord().chooseNewSyncSource(now()++,
-                                       ourOpTime.getTimestamp(),
-                                       TopologyCoordinator::ChainingPreference::kUseConfiguration);
+    getTopoCoord().chooseNewSyncSource(
+        now()++, ourOpTime, TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h6"), getTopoCoord().getSyncSourceAddress());
 }
 
@@ -1380,7 +1380,7 @@ TEST_F(TopoCoordTest,
     ASSERT_FALSE(responseObj.hasField("warning"));
     receiveDownHeartbeat(HostAndPort("h6"), "rs0", OpTime());
     HostAndPort syncSource = getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h6"), syncSource);
 }
 
@@ -1494,9 +1494,8 @@ TEST_F(TopoCoordTest,
     BSONObj responseObj = response.obj();
     ASSERT_FALSE(responseObj.hasField("warning"));
     ASSERT_FALSE(responseObj.hasField("prevSyncTarget"));
-    getTopoCoord().chooseNewSyncSource(now()++,
-                                       ourOpTime.getTimestamp(),
-                                       TopologyCoordinator::ChainingPreference::kUseConfiguration);
+    getTopoCoord().chooseNewSyncSource(
+        now()++, ourOpTime, TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h5"), getTopoCoord().getSyncSourceAddress());
 
     heartbeatFromMember(
@@ -4893,7 +4892,7 @@ TEST_F(PrepareHeartbeatResponseTest,
     heartbeatFromMember(
         HostAndPort("h2"), "rs0", MemberState::RS_SECONDARY, OpTime(Timestamp(1, 0), 0));
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
 
     // set up args
     ReplSetHeartbeatArgs args;
diff --git a/src/mongo/db/repl/topology_coordinator_impl_v1_test.cpp b/src/mongo/db/repl/topology_coordinator_impl_v1_test.cpp
index 851de44c9f8..3cb7f7ec038 100644
--- a/src/mongo/db/repl/topology_coordinator_impl_v1_test.cpp
+++ b/src/mongo/db/repl/topology_coordinator_impl_v1_test.cpp
@@ -251,7 +251,7 @@ private:
 TEST_F(TopoCoordTest, NodeReturnsSecondaryWithMostRecentDataAsSyncSource) {
     // if we do not have an index in the config, we should get an empty syncsource
     HostAndPort newSyncSource = getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_TRUE(newSyncSource.empty());
 
     updateConfig(BSON("_id"
@@ -278,7 +278,7 @@ TEST_F(TopoCoordTest, NodeReturnsSecondaryWithMostRecentDataAsSyncSource) {
 
     // Fail due to insufficient number of pings
     newSyncSource = getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(getTopoCoord().getSyncSourceAddress(), newSyncSource);
     ASSERT(getTopoCoord().getSyncSourceAddress().empty());
 
@@ -289,7 +289,7 @@ TEST_F(TopoCoordTest, NodeReturnsSecondaryWithMostRecentDataAsSyncSource) {
 
     // Should choose h2, since it is furthest ahead
     newSyncSource = getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(getTopoCoord().getSyncSourceAddress(), newSyncSource);
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
@@ -297,34 +297,34 @@ TEST_F(TopoCoordTest, NodeReturnsSecondaryWithMostRecentDataAsSyncSource) {
     heartbeatFromMember(
         HostAndPort("h3"), "rs0", MemberState::RS_SECONDARY, OpTime(Timestamp(2, 0), 0));
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
 
     // h3 becomes an invalid candidate for sync source; should choose h2 again
     heartbeatFromMember(
         HostAndPort("h3"), "rs0", MemberState::RS_RECOVERING, OpTime(Timestamp(2, 0), 0));
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
     // h3 back in SECONDARY and ahead
     heartbeatFromMember(
         HostAndPort("h3"), "rs0", MemberState::RS_SECONDARY, OpTime(Timestamp(2, 0), 0));
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
 
     // h3 goes down
     receiveDownHeartbeat(HostAndPort("h3"), "rs0", OpTime());
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
     // h3 back up and ahead
     heartbeatFromMember(
         HostAndPort("h3"), "rs0", MemberState::RS_SECONDARY, OpTime(Timestamp(2, 0), 0));
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
 }
 
@@ -369,7 +369,7 @@ TEST_F(TopoCoordTest, NodeReturnsClosestValidSyncSourceAsSyncSource) {
                  0);
 
     setSelfMemberState(MemberState::RS_SECONDARY);
-    Timestamp lastOpTimeWeApplied = Timestamp(100, 0);
+    OpTime lastOpTimeWeApplied = OpTime(Timestamp(100, 0), 0);
 
     heartbeatFromMember(HostAndPort("h1"),
                         "rs0",
@@ -500,6 +500,57 @@ TEST_F(TopoCoordTest, NodeReturnsClosestValidSyncSourceAsSyncSource) {
     ASSERT(getTopoCoord().getSyncSourceAddress().empty());
 }
 
+TEST_F(TopoCoordTest, NodeWontChooseSyncSourceFromOlderTerm) {
+    updateConfig(BSON("_id"
+                      << "rs0"
+                      << "version"
+                      << 1
+                      << "members"
+                      << BSON_ARRAY(BSON("_id" << 1 << "host"
+                                               << "hself")
+                                    << BSON("_id" << 10 << "host"
+                                                  << "h1")
+                                    << BSON("_id" << 20 << "host"
+                                                  << "h2"))),
+                 0);
+
+    setSelfMemberState(MemberState::RS_SECONDARY);
+    OpTime lastOpTimeWeApplied = OpTime(Timestamp(100, 0), 3);
+
+    heartbeatFromMember(HostAndPort("h1"),
+                        "rs0",
+                        MemberState::RS_SECONDARY,
+                        OpTime(Timestamp(200, 0), 3),
+                        Milliseconds(200));
+    heartbeatFromMember(HostAndPort("h2"),
+                        "rs0",
+                        MemberState::RS_SECONDARY,
+                        OpTime(Timestamp(300, 0), 2),  // old term
+                        Milliseconds(100));
+
+    // Record 2nd round of pings to allow choosing a new sync source
+    heartbeatFromMember(HostAndPort("h1"),
+                        "rs0",
+                        MemberState::RS_SECONDARY,
+                        OpTime(Timestamp(200, 0), 3),
+                        Milliseconds(200));
+    heartbeatFromMember(HostAndPort("h2"),
+                        "rs0",
+                        MemberState::RS_SECONDARY,
+                        OpTime(Timestamp(300, 0), 2),  // old term
+                        Milliseconds(100));
+
+    getTopoCoord().chooseNewSyncSource(
+        now()++, lastOpTimeWeApplied, TopologyCoordinator::ChainingPreference::kUseConfiguration);
+    ASSERT_EQUALS(HostAndPort("h1"), getTopoCoord().getSyncSourceAddress());
+
+    // h1 goes down; no sync source candidates remain
+    receiveDownHeartbeat(HostAndPort("h1"), "rs0", OpTime());
+    getTopoCoord().chooseNewSyncSource(
+        now()++, lastOpTimeWeApplied, TopologyCoordinator::ChainingPreference::kUseConfiguration);
+    ASSERT(getTopoCoord().getSyncSourceAddress().empty());
+}
+
 
 TEST_F(TopoCoordTest, ChooseOnlyPrimaryAsSyncSourceWhenChainingIsDisallowed) {
     updateConfig(BSON("_id"
@@ -544,7 +595,7 @@ TEST_F(TopoCoordTest, ChooseOnlyPrimaryAsSyncSourceWhenChainingIsDisallowed) {
     ASSERT_EQUALS(
         HostAndPort(),
         getTopoCoord().chooseNewSyncSource(
-            now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
+            now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
     ASSERT(getTopoCoord().getSyncSourceAddress().empty());
 
     // Add primary
@@ -559,18 +610,20 @@ TEST_F(TopoCoordTest, ChooseOnlyPrimaryAsSyncSourceWhenChainingIsDisallowed) {
     // h3 is primary and should be chosen as the sync source when we are not in catch-up mode,
     // despite being further away than h2 and the primary (h3) being behind our most recently
     // applied optime.
-    ASSERT_EQUALS(
-        HostAndPort("h3"),
-        getTopoCoord().chooseNewSyncSource(
-            now()++, Timestamp(10, 0), TopologyCoordinator::ChainingPreference::kUseConfiguration));
+    ASSERT_EQUALS(HostAndPort("h3"),
+                  getTopoCoord().chooseNewSyncSource(
+                      now()++,
+                      OpTime(Timestamp(10, 0), 0),
+                      TopologyCoordinator::ChainingPreference::kUseConfiguration));
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
 
     // When we are in catch-up mode, the chainingAllowed setting is ignored. h2 should be chosen as
     // the sync source.
-    ASSERT_EQUALS(
-        HostAndPort("h2"),
-        getTopoCoord().chooseNewSyncSource(
-            now()++, Timestamp(10, 0), TopologyCoordinator::ChainingPreference::kAllowChaining));
+    ASSERT_EQUALS(HostAndPort("h2"),
+                  getTopoCoord().chooseNewSyncSource(
+                      now()++,
+                      OpTime(Timestamp(10, 0), 0),
+                      TopologyCoordinator::ChainingPreference::kAllowChaining));
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
     // Become primary: should not choose self as sync source.
@@ -584,7 +637,7 @@ TEST_F(TopoCoordTest, ChooseOnlyPrimaryAsSyncSourceWhenChainingIsDisallowed) {
     ASSERT_EQUALS(
         HostAndPort(),
         getTopoCoord().chooseNewSyncSource(
-            now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
+            now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
     ASSERT(getTopoCoord().getSyncSourceAddress().empty());
 }
 
@@ -600,7 +653,7 @@ TEST_F(TopoCoordTest, ChooseOnlyVotersAsSyncSourceWhenNodeIsAVoter) {
 
     HostAndPort h2("h2"), h3("h3");
     Timestamp t1(1, 0), t5(5, 0), t10(10, 0);
-    OpTime ot1(t1, 0), ot5(t5, 0);
+    OpTime ot1(t1, 0), ot5(t5, 0), ot10(t10, 0);
     Milliseconds hbRTT100(100), hbRTT300(300);
 
     // Two rounds of heartbeat pings from each member.
@@ -611,18 +664,18 @@ TEST_F(TopoCoordTest, ChooseOnlyVotersAsSyncSourceWhenNodeIsAVoter) {
 
     // Should choose h3 as it is a voter
     auto newSource = getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(h3, newSource);
 
     // Can't choose h2 as it is not a voter
     newSource = getTopoCoord().chooseNewSyncSource(
-        now()++, t10, TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, ot10, TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort(), newSource);
 
     // Should choose h3 as it is a voter, and ahead
     heartbeatFromMember(h3, "rs0", MemberState::RS_SECONDARY, ot5, hbRTT300);
     newSource = getTopoCoord().chooseNewSyncSource(
-        now()++, t1, TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, ot1, TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(h3, newSource);
 }
 
@@ -668,7 +721,7 @@ TEST_F(TopoCoordTest, ChooseSameSyncSourceEvenWhenPrimary) {
     ASSERT_EQUALS(
         HostAndPort("h2"),
         getTopoCoord().chooseNewSyncSource(
-            now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
+            now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
     // Become primary
@@ -679,7 +732,7 @@ TEST_F(TopoCoordTest, ChooseSameSyncSourceEvenWhenPrimary) {
     ASSERT_EQUALS(
         HostAndPort("h2"),
         getTopoCoord().chooseNewSyncSource(
-            now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
+            now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 }
 
@@ -713,7 +766,7 @@ TEST_F(TopoCoordTest, ChooseRequestedSyncSourceOnlyTheFirstTimeAfterTheSyncSourc
 
     // force should overrule other defaults
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
     getTopoCoord().setForceSyncSourceIndex(1);
     // force should cause shouldChangeSyncSource() to return true
@@ -723,12 +776,12 @@ TEST_F(TopoCoordTest, ChooseRequestedSyncSourceOnlyTheFirstTimeAfterTheSyncSourc
     ASSERT_TRUE(getTopoCoord().shouldChangeSyncSource(
         HostAndPort("h3"), OpTime(), makeMetadata(newOpTime), now()));
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
     // force should only work for one call to chooseNewSyncSource
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
 }
 
@@ -771,19 +824,19 @@ TEST_F(TopoCoordTest, NodeDoesNotChooseBlacklistedSyncSourceUntilBlacklistingExp
                         Milliseconds(100));
 
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
 
     Date_t expireTime = Date_t::fromMillisSinceEpoch(1000);
     getTopoCoord().blacklistSyncSource(HostAndPort("h3"), expireTime);
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     // Should choose second best choice now that h3 is blacklisted.
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
     // After time has passed, should go back to original sync source
     getTopoCoord().chooseNewSyncSource(
-        expireTime, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        expireTime, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h3"), getTopoCoord().getSyncSourceAddress());
 }
 
@@ -829,19 +882,19 @@ TEST_F(TopoCoordTest, ChooseNoSyncSourceWhenPrimaryIsBlacklistedAndChainingIsDis
                         Milliseconds(100));
 
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 
     Date_t expireTime = Date_t::fromMillisSinceEpoch(1000);
     getTopoCoord().blacklistSyncSource(HostAndPort("h2"), expireTime);
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     // Can't choose any sync source now.
     ASSERT(getTopoCoord().getSyncSourceAddress().empty());
 
     // After time has passed, should go back to the primary
     getTopoCoord().chooseNewSyncSource(
-        expireTime, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        expireTime, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h2"), getTopoCoord().getSyncSourceAddress());
 }
 
@@ -886,7 +939,7 @@ TEST_F(TopoCoordTest, NodeChangesToRecoveringWhenOnlyUnauthorizedNodesAreUp) {
     ASSERT_EQUALS(
         HostAndPort("h3"),
         getTopoCoord().chooseNewSyncSource(
-            now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
+            now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration));
     ASSERT_EQUALS(MemberState::RS_SECONDARY, getTopoCoord().getMemberState().s);
     // Good state setup done
 
@@ -895,7 +948,7 @@ TEST_F(TopoCoordTest, NodeChangesToRecoveringWhenOnlyUnauthorizedNodesAreUp) {
     receiveDownHeartbeat(HostAndPort("h3"), "rs0", OpTime(), ErrorCodes::NetworkTimeout);
     ASSERT_TRUE(getTopoCoord()
                     .chooseNewSyncSource(now()++,
-                                         Timestamp(),
+                                         OpTime(),
                                          TopologyCoordinator::ChainingPreference::kUseConfiguration)
                     .empty());
     ASSERT_EQUALS(MemberState::RS_SECONDARY, getTopoCoord().getMemberState().s);
@@ -905,7 +958,7 @@ TEST_F(TopoCoordTest, NodeChangesToRecoveringWhenOnlyUnauthorizedNodesAreUp) {
     receiveDownHeartbeat(HostAndPort("h3"), "rs0", OpTime(), ErrorCodes::Unauthorized);
     ASSERT_TRUE(getTopoCoord()
                     .chooseNewSyncSource(now()++,
-                                         Timestamp(),
+                                         OpTime(),
                                          TopologyCoordinator::ChainingPreference::kUseConfiguration)
                     .empty());
     ASSERT_EQUALS(MemberState::RS_RECOVERING, getTopoCoord().getMemberState().s);
@@ -1281,9 +1334,8 @@ TEST_F(TopoCoordTest, ChooseRequestedNodeWhenSyncFromRequestsAStaleNode) {
     ASSERT_OK(result);
     ASSERT_EQUALS("requested member \"h5:27017\" is more than 10 seconds behind us",
                   response.obj()["warning"].String());
-    getTopoCoord().chooseNewSyncSource(now()++,
-                                       ourOpTime.getTimestamp(),
-                                       TopologyCoordinator::ChainingPreference::kUseConfiguration);
+    getTopoCoord().chooseNewSyncSource(
+        now()++, ourOpTime, TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h5"), getTopoCoord().getSyncSourceAddress());
 }
 
@@ -1330,9 +1382,8 @@ TEST_F(TopoCoordTest, ChooseRequestedNodeWhenSyncFromRequestsAValidNode) {
     ASSERT_OK(result);
     BSONObj responseObj = response.obj();
     ASSERT_FALSE(responseObj.hasField("warning"));
-    getTopoCoord().chooseNewSyncSource(now()++,
-                                       ourOpTime.getTimestamp(),
-                                       TopologyCoordinator::ChainingPreference::kUseConfiguration);
+    getTopoCoord().chooseNewSyncSource(
+        now()++, ourOpTime, TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h6"), getTopoCoord().getSyncSourceAddress());
 }
 
@@ -1381,7 +1432,7 @@ TEST_F(TopoCoordTest,
     ASSERT_FALSE(responseObj.hasField("warning"));
     receiveDownHeartbeat(HostAndPort("h6"), "rs0", OpTime());
     HostAndPort syncSource = getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h6"), syncSource);
 }
 
@@ -1495,9 +1546,8 @@ TEST_F(TopoCoordTest,
     BSONObj responseObj = response.obj();
     ASSERT_FALSE(responseObj.hasField("warning"));
     ASSERT_FALSE(responseObj.hasField("prevSyncTarget"));
-    getTopoCoord().chooseNewSyncSource(now()++,
-                                       ourOpTime.getTimestamp(),
-                                       TopologyCoordinator::ChainingPreference::kUseConfiguration);
+    getTopoCoord().chooseNewSyncSource(
+        now()++, ourOpTime, TopologyCoordinator::ChainingPreference::kUseConfiguration);
     ASSERT_EQUALS(HostAndPort("h5"), getTopoCoord().getSyncSourceAddress());
 
     heartbeatFromMember(
@@ -1960,7 +2010,7 @@ TEST_F(PrepareHeartbeatResponseV1Test,
     heartbeatFromMember(
         HostAndPort("h2"), "rs0", MemberState::RS_SECONDARY, OpTime(Timestamp(1, 0), 0));
     getTopoCoord().chooseNewSyncSource(
-        now()++, Timestamp(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
+        now()++, OpTime(), TopologyCoordinator::ChainingPreference::kUseConfiguration);
 
     // set up args
     ReplSetHeartbeatArgsV1 args;