[FIXED] JetStream: sampling not updated during consumer update

Resolves #2941

Signed-off-by: Ivan Kozlovic <ivan@synadia.com>

server/consumer.go

@@ -1350,6 +1350,13 @@ func (o *consumer) updateConfig(cfg *ConsumerConfig) error {
 		// We need both locks here so do in Go routine.
 		go o.setRateLimitNeedsLocks()
 	}
+	if cfg.SampleFrequency != o.cfg.SampleFrequency {
+		s := strings.TrimSuffix(cfg.SampleFrequency, "%")
+		// String has been already verified for validity up in the stack, so no
+		// need to check for error here.
+		sampleFreq, _ := strconv.Atoi(s)
+		o.sfreq = int32(sampleFreq)
+	}
 
 	// Record new config for others that do not need special handling.
 	// Allowed but considered no-op, [Description, MaxDeliver, SampleFrequency, MaxWaiting, HeadersOnly]

server/jetstream_test.go

@@ -16080,8 +16080,6 @@ func TestJetStreamConsumerAckSampling(t *testing.T) {
 }
 
 func TestJetStreamConsumerAckSamplingSpecifiedUsingUpdateConsumer(t *testing.T) {
-	t.Skip("sampling msg is not sent when sampling option is part of update flow")
-
 	s := RunBasicJetStreamServer()
 	if config := s.JetStreamConfig(); config != nil {
 		defer removeDir(t, config.StoreDir)