SERVER-35951 Fix to prevent race between repl set unfreeze and _startElectSelfIfEligibleV1 (election timeout) for pv1 single node replica set case.

(cherry picked from commit 32bd1c03753a5cd349841eea0d5541e1f3f1305d)

1 files changed, 7 insertions, 6 deletions

diff --git a/src/mongo/db/repl/replication_coordinator_impl.cpp b/src/mongo/db/repl/replication_coordinator_impl.cpp
index ea0b52b58ac..c50dcf751a6 100644
--- a/src/mongo/db/repl/replication_coordinator_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl.cpp
@@ -1782,7 +1782,7 @@ void ReplicationCoordinatorImpl::_handleTimePassing(
     // against other elections caused by events like election timeout, replSetStepUp etc.
     if (isV1ElectionProtocol()) {
         _startElectSelfIfEligibleV1(
-            TopologyCoordinator::StartElectionReason::kSingleNodeStepDownTimeout);
+            TopologyCoordinator::StartElectionReason::kSingleNodePromptElection);
         return;
     }
 
@@ -2131,11 +2131,12 @@ Status ReplicationCoordinatorImpl::processReplSetFreeze(int secs, BSONObjBuilder
         return result.getStatus();
     }
 
-    if (TopologyCoordinator::PrepareFreezeResponseResult::kElectSelf == result.getValue()) {
-        // If we just unfroze and ended our stepdown period and we are a one node replica set,
-        // the topology coordinator will have gone into the candidate role to signal that we
-        // need to elect ourself.
-        _performPostMemberStateUpdateAction(kActionWinElection);
+    if (TopologyCoordinator::PrepareFreezeResponseResult::kSingleNodeSelfElect ==
+        result.getValue()) {
+        // For election protocol v1, call _startElectSelfIfEligibleV1 to avoid race
+        // against other elections caused by events like election timeout, replSetStepUp etc.
+        _startElectSelfIfEligibleV1(
+            TopologyCoordinator::StartElectionReason::kSingleNodePromptElection);
     }
 
     return Status::OK();