SERVER-36474 Cannot initiate a replica set if free monitoring is disabled at command-line

2 files changed, 43 insertions, 1 deletions

diff --git a/jstests/free_mon/free_mon_rs_off.js b/jstests/free_mon/free_mon_rs_off.js
new file mode 100644
index 00000000000..a15519bd2ac
--- /dev/null
+++ b/jstests/free_mon/free_mon_rs_off.js
@@ -0,0 +1,38 @@
+// Validate replica set starts up with free monitoring disabled
+//
+load("jstests/free_mon/libs/free_mon.js");
+
+(function() {
+    'use strict';
+
+    let mock_web = new FreeMonWebServer();
+
+    mock_web.start();
+
+    let options = {
+        setParameter: "cloudFreeMonitoringEndpointURL=" + mock_web.getURL(),
+        enableFreeMonitoring: "off",
+        verbose: 1,
+    };
+
+    const rst = new ReplSetTest({nodes: 2, nodeOptions: options});
+
+    rst.startSet();
+    rst.initiate();
+    rst.awaitReplication();
+
+    const retStatus1 = rst.getPrimary().adminCommand({getFreeMonitoringStatus: 1});
+    assert.commandWorked(retStatus1);
+    assert.eq(retStatus1.state, "disabled", tojson(retStatus1));
+
+    const stats = mock_web.queryStats();
+    print(tojson(stats));
+
+    assert.eq(stats.registers, 0);
+
+    assert.commandFailed(rst.getPrimary().adminCommand({setFreeMonitoring: 1, action: "disable"}));
+
+    rst.stopSet();
+
+    mock_web.stop();
+})();
diff --git a/src/mongo/db/free_mon/free_mon_mongod.cpp b/src/mongo/db/free_mon/free_mon_mongod.cpp
index 112136fe8ca..f4a9c67cadb 100644
--- a/src/mongo/db/free_mon/free_mon_mongod.cpp
+++ b/src/mongo/db/free_mon/free_mon_mongod.cpp
@@ -386,7 +386,11 @@ void stopFreeMonitoring() {
 }
 
 void notifyFreeMonitoringOnTransitionToPrimary() {
-    FreeMonController::get(getGlobalServiceContext())->notifyOnTransitionToPrimary();
+    auto controller = FreeMonController::get(getGlobalServiceContext());
+
+    if (controller != nullptr) {
+        controller->notifyOnTransitionToPrimary();
+    }
 }
 
 void setupFreeMonitoringOpObserver(OpObserverRegistry* registry) {