What causes "no RocketMQ master broker found for topic %s" in t8y2/dbx?

Verify the topic exists and has queues on a master broker (mqadmin topicRoute)

no RocketMQ master broker found for topic %s

Error message

no RocketMQ master broker found for topic %s

What it means

readConsumerStatusFromBrokers requires at least one master broker address for the topic before issuing GetConsumerStatus requests; an empty address list means no master broker is serving the topic, so it errors with the topic name.

Source

Thrown at agents/drivers/rocketmq/consumers.go:322

	route, err := r.client.ExamineTopicRouteInfo(ctx, topic)
	if err != nil {
		return nil, err
	}
	return readConsumerStatusFromBrokers(
		ctx, masterAddressesFromRoute(route), topic, groupID, clientAddr, r.invoke,
	)
}

func readConsumerStatusFromBrokers(
	ctx context.Context,
	addresses []string,
	topic string,
	groupID string,
	clientAddr string,
	invoke consumerStatusInvoker,
) (map[string]map[string]int64, error) {
	if len(addresses) == 0 {
		return nil, fmt.Errorf("no RocketMQ master broker found for topic %s", topic)
	}
	orderedAddresses := append([]string(nil), addresses...)
	sort.Strings(orderedAddresses)
	merged := make(map[string]map[string]int64)
	successCount := 0
	var lastErr error
	for _, address := range orderedAddresses {
		fields := map[string]string{"topic": topic, "group": groupID}
		if clientAddr != "" {
			fields["clientAddr"] = clientAddr
		}
		response, requestErr := invoke(ctx, address,
			remoting.NewRequest(remoting.InvokeBrokerToGetConsumerStatus, fields))
		if requestErr != nil {
			lastErr = requestErr
			continue
		}
		if response == nil {

View on GitHub (pinned to c0390bff16)

Solutions

Verify the topic exists and has queues on a master broker (mqadmin topicRoute)
Ensure the master broker for the topic is running and reachable
Double-check the topic spelling and cluster you are querying

Example fix

// before
GetConsumeStatus(ctx, "topik-name", "group")  // typo'd topic, no route
// after
GetConsumeStatus(ctx, "topic-name", "group")  // existing topic with master route

Defensive patterns

Strategy: validation

Validate before calling

route, err := adminClient.FetchTopicRoute(topic)
if err != nil || len(route) == 0 {
    return fmt.Errorf("topic %s has no route/master broker; check topic exists", topic)
}

Type guard

func hasMasterForTopic(route []brokerInfo) bool {
    for _, b := range route { if b.ReadableQueueNums > 0 { return true } }
    return false
}

Try / catch

status, err := GetConsumeStatus(ctx, topic, group)
if err != nil && strings.Contains(err.Error(), "no RocketMQ master broker") {
    return fmt.Errorf("topic %s not available: deploy topic / start master broker", topic)
}

Prevention

Create topics with writable/readable queues on masters
Monitor master broker health for key topics
Validate topic names against a cluster listing before calls

When it happens

Trigger: GetConsumeStatus resolving topic routes yields zero master broker addresses (all brokers are slaves, topic not deployed, or route info empty).

Common situations: Topic created with no queues on a readable master; master broker down while only slaves survive; topic name typo so route lookup returns nothing; name-server metadata stale.

Related errors

AI-assisted analysis of t8y2/dbx@c0390bff16 (2026-09-05). Data as JSON: /api/errors/b494153896463c0d. Report an issue: GitHub.