SERVER-47435 Incrementing topologyVersion for FCV change must update awaitingTopologyChanges

1 files changed, 48 insertions, 0 deletions

diff --git a/jstests/replsets/awaitable_ismaster_fcv_change.js b/jstests/replsets/awaitable_ismaster_fcv_change.js
index 2c8e10be5cd..535306964a2 100644
--- a/jstests/replsets/awaitable_ismaster_fcv_change.js
+++ b/jstests/replsets/awaitable_ismaster_fcv_change.js
@@ -101,12 +101,28 @@ let awaitIsMasterBeforeDowngradeFCVOnSecondary =
 primaryFailPoint.wait();
 secondaryFailPoint.wait();
 
+// Each node has one isMaster request waiting on a topology change.
+let numAwaitingTopologyChangeOnPrimary =
+    primaryAdminDB.serverStatus().connections.awaitingTopologyChanges;
+let numAwaitingTopologyChangeOnSecondary =
+    secondaryAdminDB.serverStatus().connections.awaitingTopologyChanges;
+assert.eq(1, numAwaitingTopologyChangeOnPrimary);
+assert.eq(1, numAwaitingTopologyChangeOnSecondary);
+
 // Setting the FCV to the same version will not trigger an isMaster response.
 assert.commandWorked(
     primaryAdminDB.runCommand({setFeatureCompatibilityVersion: latestFCV, writeConcern: {w: 1}}));
 checkFCV(primaryAdminDB, latestFCV);
 checkFCV(secondaryAdminDB, latestFCV);
 
+// Each node still has one isMaster request waiting on a topology change.
+numAwaitingTopologyChangeOnPrimary =
+    primaryAdminDB.serverStatus().connections.awaitingTopologyChanges;
+numAwaitingTopologyChangeOnSecondary =
+    secondaryAdminDB.serverStatus().connections.awaitingTopologyChanges;
+assert.eq(1, numAwaitingTopologyChangeOnPrimary);
+assert.eq(1, numAwaitingTopologyChangeOnSecondary);
+
 jsTestLog("Downgrade the featureCompatibilityVersion.");
 // Downgrading the FCV will cause the isMaster requests to respond on both primary and secondary.
 assert.commandWorked(primaryAdminDB.runCommand(
@@ -118,6 +134,14 @@ rst.awaitReplication();
 checkFCV(primaryAdminDB, lastStableFCV);
 checkFCV(secondaryAdminDB, lastStableFCV);
 
+// All isMaster requests should have been responded to after the FCV change.
+numAwaitingTopologyChangeOnPrimary =
+    primaryAdminDB.serverStatus().connections.awaitingTopologyChanges;
+numAwaitingTopologyChangeOnSecondary =
+    secondaryAdminDB.serverStatus().connections.awaitingTopologyChanges;
+assert.eq(0, numAwaitingTopologyChangeOnPrimary);
+assert.eq(0, numAwaitingTopologyChangeOnSecondary);
+
 // Get the new topologyVersion.
 const primaryResponseAfterDowngrade = assert.commandWorked(primaryAdminDB.runCommand({
     isMaster: 1,
@@ -156,12 +180,28 @@ let awaitIsMasterBeforeUpgradeFCVOnSecondary =
 primaryFailPoint.wait();
 secondaryFailPoint.wait();
 
+// Each node has one isMaster request waiting on a topology change.
+numAwaitingTopologyChangeOnPrimary =
+    primaryAdminDB.serverStatus().connections.awaitingTopologyChanges;
+numAwaitingTopologyChangeOnSecondary =
+    secondaryAdminDB.serverStatus().connections.awaitingTopologyChanges;
+assert.eq(1, numAwaitingTopologyChangeOnPrimary);
+assert.eq(1, numAwaitingTopologyChangeOnSecondary);
+
 // Setting the FCV to the same version will not trigger an isMaster response.
 assert.commandWorked(primaryAdminDB.runCommand(
     {setFeatureCompatibilityVersion: lastStableFCV, writeConcern: {w: 1}}));
 checkFCV(primaryAdminDB, lastStableFCV);
 checkFCV(secondaryAdminDB, lastStableFCV);
 
+// Each node still has one isMaster request waiting on a topology change.
+numAwaitingTopologyChangeOnPrimary =
+    primaryAdminDB.serverStatus().connections.awaitingTopologyChanges;
+numAwaitingTopologyChangeOnSecondary =
+    secondaryAdminDB.serverStatus().connections.awaitingTopologyChanges;
+assert.eq(1, numAwaitingTopologyChangeOnPrimary);
+assert.eq(1, numAwaitingTopologyChangeOnSecondary);
+
 jsTestLog("Upgrade the featureCompatibilityVersion.");
 // Upgrading the FCV will cause the isMaster requests to respond on both primary and secondary.
 assert.commandWorked(
@@ -173,5 +213,13 @@ rst.awaitReplication();
 checkFCV(primaryAdminDB, latestFCV);
 checkFCV(secondaryAdminDB, latestFCV);
 
+// All isMaster requests should have been responded to after the FCV change.
+numAwaitingTopologyChangeOnPrimary =
+    primaryAdminDB.serverStatus().connections.awaitingTopologyChanges;
+numAwaitingTopologyChangeOnSecondary =
+    secondaryAdminDB.serverStatus().connections.awaitingTopologyChanges;
+assert.eq(0, numAwaitingTopologyChangeOnPrimary);
+assert.eq(0, numAwaitingTopologyChangeOnSecondary);
+
 rst.stopSet();
 })();