alibaba/canal · error · CanalClientException

mq not support this method

Error message

mq not support this method

What it means

Error "mq not support this method" thrown in alibaba/canal.

Source

Thrown at client/src/main/java/com/alibaba/otter/canal/client/kafka/KafkaCanalConnector.java:282

     */
    @Override
    public void ack() {
        waitClientRunning();
        if (!running) {
            return;
        }

        if (kafkaConsumer != null) {
            kafkaConsumer.commitSync();
        }
        if (kafkaConsumer2 != null) {
            kafkaConsumer2.commitSync();
        }
    }

    @Override
    public void subscribe(String filter) throws CanalClientException {
        throw new CanalClientException("mq not support this method");
    }

    @Override
    public Message get(int batchSize) throws CanalClientException {
        throw new CanalClientException("mq not support this method");
    }

    @Override
    public Message get(int batchSize, Long timeout, TimeUnit unit) throws CanalClientException {
        throw new CanalClientException("mq not support this method");
    }

    @Override
    public Message getWithoutAck(int batchSize) throws CanalClientException {
        throw new CanalClientException("mq not support this method");
    }

    @Override

View on GitHub (pinned to 87be50e876)

Solutions

1. Do not call subscribe/unSubscribe/rollback on the Kafka connector; MQ connectors only support get/ack semantics over consumed messages.
2. Manage offsets through Kafka consumer group configuration instead of canal subscribe APIs.

When it happens

Trigger: Thrown at client/src/main/java/com/alibaba/otter/canal/client/kafka/KafkaCanalConnector.java:282 when the library encounters an invalid state.

Common situations: Unsupported method on an MQ-backed connector. Keep the guard: Kafka connectors cannot support server-style subscribe semantics; callers should check connector type before invoking.

AI-assisted analysis of alibaba/canal@87be50e876 (2026-08-14). Data as JSON: /api/errors/4ec56e9a87da501d. Report an issue: GitHub.