fix: reschedule monitoring before emitting heartbeat events

mongodb · Jan 1, 2020 · 7fcbeb5 · 7fcbeb5
1 parent a13dc68
commit 7fcbeb5
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Showing 2 changed files with 12 additions and 11 deletions.
diff --git a/lib/core/sdam/monitor.js b/lib/core/sdam/monitor.js
@@ -213,33 +213,35 @@ function rescheduleMonitoring(monitor, ms) {
     return;
   }
 
+  stateTransition(monitor, STATE_IDLE);
+
   monitor[kLastCheckTime] = process.hrtime();
   monitor[kMonitorId] = setTimeout(() => {
     monitor[kMonitorId] = undefined;
     monitor.requestCheck();
   }, ms || heartbeatFrequencyMS);
-
-  stateTransition(monitor, STATE_IDLE);
 }
 
 function successHandler(monitor, start, isMaster) {
+  rescheduleMonitoring(monitor);
+
   process.nextTick(() =>
     monitor.emit(
       'serverHeartbeatSucceeded',
       new ServerHeartbeatSucceededEvent(calculateDurationInMs(start), isMaster, monitor.address)
     )
   );
-
-  rescheduleMonitoring(monitor);
 }
 
 function failureHandler(monitor, start, err) {
-  monitor.emit(
-    'serverHeartbeatFailed',
-    new ServerHeartbeatFailedEvent(calculateDurationInMs(start), err, monitor.address)
-  );
-
   rescheduleMonitoring(monitor);
+
+  process.nextTick(() =>
+    monitor.emit(
+      'serverHeartbeatFailed',
+      new ServerHeartbeatFailedEvent(calculateDurationInMs(start), err, monitor.address)
+    )
+  );
 }
 
 module.exports = {

diff --git a/test/unit/sdam/monitoring.test.js b/test/unit/sdam/monitoring.test.js
@@ -78,8 +78,7 @@ describe('monitoring', function() {
       acceptConnections = true;
     }, 250);
 
-    // set `heartbeatFrequencyMS` to 250ms to force a quick monitoring check, and wait 500ms to validate below
-    const topology = new Topology(mockServer.uri(), { heartbeatFrequencyMS: 250 });
+    const topology = new Topology(mockServer.uri());
     topology.connect(err => {
       expect(err).to.not.exist;