SERVER-41507 Track the time the new term oplog entry was written in replSetStatus on primaries

5 files changed, 16 insertions, 0 deletions

diff --git a/src/mongo/db/repl/SConscript b/src/mongo/db/repl/SConscript
index 69086a7319f..5074ce190ec 100644
--- a/src/mongo/db/repl/SConscript
+++ b/src/mongo/db/repl/SConscript
@@ -1154,6 +1154,7 @@ env.Library(
         '$BUILD_DIR/mongo/db/op_observer',
         '$BUILD_DIR/mongo/db/query_exec',
         '$BUILD_DIR/mongo/db/repl/oplog_buffer_proxy',
+        '$BUILD_DIR/mongo/db/repl/replication_metrics',
         '$BUILD_DIR/mongo/db/s/balancer',
         '$BUILD_DIR/mongo/db/s/sharding_runtime_d',
         '$BUILD_DIR/mongo/db/service_context',
diff --git a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
index 65cb2744ec4..321cd206798 100644
--- a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
@@ -71,6 +71,7 @@
 #include "mongo/db/repl/repl_server_parameters_gen.h"
 #include "mongo/db/repl/repl_settings.h"
 #include "mongo/db/repl/replication_coordinator.h"
+#include "mongo/db/repl/replication_metrics.h"
 #include "mongo/db/repl/replication_process.h"
 #include "mongo/db/repl/storage_interface.h"
 #include "mongo/db/s/balancer/balancer.h"
@@ -465,6 +466,9 @@ OpTime ReplicationCoordinatorExternalStateImpl::onTransitionToPrimary(OperationC
     fassert(28665, loadLastOpTimeAndWallTimeResult);
     auto opTimeToReturn = loadLastOpTimeAndWallTimeResult.getValue().opTime;
 
+    auto newTermStartDate = loadLastOpTimeAndWallTimeResult.getValue().wallTime;
+    ReplicationMetrics::get(opCtx).setNewTermStartDate(newTermStartDate);
+
     _shardingOnTransitionToPrimaryHook(opCtx);
 
     _dropAllTempCollections(opCtx);
diff --git a/src/mongo/db/repl/replication_metrics.cpp b/src/mongo/db/repl/replication_metrics.cpp
index af4fab849b5..6603158c483 100644
--- a/src/mongo/db/repl/replication_metrics.cpp
+++ b/src/mongo/db/repl/replication_metrics.cpp
@@ -273,6 +273,11 @@ void ReplicationMetrics::setTargetCatchupOpTime(OpTime opTime) {
     _electionCandidateMetrics.setTargetCatchupOpTime(opTime);
 }
 
+void ReplicationMetrics::setNewTermStartDate(Date_t newTermStartDate) {
+    stdx::lock_guard<stdx::mutex> lk(_mutex);
+    _electionCandidateMetrics.setNewTermStartDate(newTermStartDate);
+}
+
 boost::optional<OpTime> ReplicationMetrics::getTargetCatchupOpTime_forTesting() {
     stdx::lock_guard<stdx::mutex> lk(_mutex);
     return _electionCandidateMetrics.getTargetCatchupOpTime();
@@ -294,6 +299,7 @@ BSONObj ReplicationMetrics::getElectionCandidateMetricsBSON() {
 void ReplicationMetrics::clearElectionCandidateMetrics() {
     stdx::lock_guard<stdx::mutex> lk(_mutex);
     _electionCandidateMetrics.setTargetCatchupOpTime(boost::none);
+    _electionCandidateMetrics.setNewTermStartDate(boost::none);
     _nodeIsCandidateOrPrimary = false;
 }
 
diff --git a/src/mongo/db/repl/replication_metrics.h b/src/mongo/db/repl/replication_metrics.h
index 790036be571..8781c51f6a3 100644
--- a/src/mongo/db/repl/replication_metrics.h
+++ b/src/mongo/db/repl/replication_metrics.h
@@ -83,6 +83,7 @@ public:
     // consistent state.
     void setElectionCandidateMetrics(Date_t lastElectionDate);
     void setTargetCatchupOpTime(OpTime opTime);
+    void setNewTermStartDate(Date_t newTermStartDate);
 
     boost::optional<OpTime> getTargetCatchupOpTime_forTesting();
 
diff --git a/src/mongo/db/repl/replication_metrics.idl b/src/mongo/db/repl/replication_metrics.idl
index 5821858d870..e065a86631e 100644
--- a/src/mongo/db/repl/replication_metrics.idl
+++ b/src/mongo/db/repl/replication_metrics.idl
@@ -130,6 +130,10 @@ structs:
                 description: "The node's target opTime for catchup"
                 type: optime
                 optional: true
+            newTermStartDate:
+                description: "Time the new term oplog entry was written"
+                type: date
+                optional: true
 
     ElectionParticipantMetrics:
         description: "Stores metrics that are specific to the last election in which the node voted"