Don't snapshot on monitor goroutine or Raft node quit signal unless shutting down

server/jetstream_cluster.go

@@ -2623,11 +2623,19 @@ func (js *jetStream) monitorStream(mset *stream, sa *streamAssignment, sendSnaps
 			return
 		case <-mqch:
 			// Clean signal from shutdown routine so do best effort attempt to snapshot.
-			doSnapshot()
+			// Don't snapshot if not shutting down, monitor goroutine could be going away
+			// on a scale down or a remove for example.
+			if s.isShuttingDown() {
+				doSnapshot()
+			}
 			return
 		case <-qch:
 			// Clean signal from shutdown routine so do best effort attempt to snapshot.
-			doSnapshot()
+			// Don't snapshot if not shutting down, Raft node could be going away on a
+			// scale down or remove for example.
+			if s.isShuttingDown() {
+				doSnapshot()
+			}
 			return
 		case <-aq.ch:
 			var ne, nb uint64
@@ -5521,11 +5529,19 @@ func (js *jetStream) monitorConsumer(o *consumer, ca *consumerAssignment) {
 			return
 		case <-mqch:
 			// Clean signal from shutdown routine so do best effort attempt to snapshot.
-			doSnapshot(false)
+			// Don't snapshot if not shutting down, monitor goroutine could be going away
+			// on a scale down or a remove for example.
+			if s.isShuttingDown() {
+				doSnapshot(false)
+			}
 			return
 		case <-qch:
 			// Clean signal from shutdown routine so do best effort attempt to snapshot.
-			doSnapshot(false)
+			// Don't snapshot if not shutting down, Raft node could be going away on a
+			// scale down or remove for example.
+			if s.isShuttingDown() {
+				doSnapshot(false)
+			}
 			return
 		case <-aq.ch:
 			ces := aq.pop()

server/jetstream_cluster_1_test.go

@@ -9234,13 +9234,11 @@ func TestJetStreamClusterAsyncFlushFileStoreFlushOnSnapshot(t *testing.T) {
 	// Confirm above write is pending.
 	require_Equal(t, lmb.pendingWriteSize(), 33)
 
-	// Stop stream monitor routine, which will install a snapshot on shutdown.
-	mset.mu.Lock()
-	if mset.mqch != nil {
-		close(mset.mqch)
-		mset.mqch = nil
-	}
-	mset.mu.Unlock()
+	// Make the upper layer snapshot by sending leader change signal.
+	// It doesn't matter that we're already leader, it still gets handled.
+	// Previously this used the mqch, but that now only snapshots on shutdown.
+	n.leadc <- true
+
 	checkFor(t, 2*time.Second, 200*time.Millisecond, func() error {
 		n.Lock()
 		snap, err := n.loadLastSnapshot()