apache/pulsar · warning · UnsupportedOperationException

not implemented

Error message

not implemented

What it means

SinkContext.seek(topic, partition, messageId) is a default method throwing UnsupportedOperationException('not implemented') because the base interface does not implement repositioning the subscription to a specific MessageId. Only concrete runtime contexts that implement seek will work; otherwise any call fails.

Source

Thrown at pulsar-io/core/src/main/java/org/apache/pulsar/io/core/SinkContext.java:75

    /**
     * Get subscription type used by the source providing data for the sink.
     *
     * @return subscription type
     */
    default SubscriptionType getSubscriptionType() {
        throw new UnsupportedOperationException("Context does not provide SubscriptionType");
    }

    /**
     * Reset the subscription associated with this topic and partition to a specific message id.
     *
     * @param topic - topic name
     * @param partition - partition id (0 for non-partitioned topics)
     * @param messageId to reset to
     * @throws PulsarClientException
     */
    default void seek(String topic, int partition, MessageId messageId) throws PulsarClientException {
        throw new UnsupportedOperationException("not implemented");
    }

    /**
     * Stop requesting new messages for given topic and partition until {@link #resume(String topic, int partition)}
     * is called.
     *
     * @param topic - topic name
     * @param partition - partition id (0 for non-partitioned topics)
     */
    default void pause(String topic, int partition) throws PulsarClientException {
        throw new UnsupportedOperationException("not implemented");
    }

    /**
     * Resume requesting messages.
     * @param topic - topic name
     * @param partition - partition id (0 for non-partitioned topics)
     */

View on GitHub (pinned to 820761864e)

Solutions

1. Upgrade the Pulsar functions runtime to a version where SinkContext.seek is implemented.
2. Wrap the call in try-catch for UnsupportedOperationException and degrade gracefully (skip repositioning, log).
3. Use a PulsarClient Consumer.seek directly if the sink has access to a client and topic instead of relying on SinkContext.
4. In tests, stub seek to record the call.

Example fix

// before
ctx.seek(topic, partition, msgId);
// after
try {
    ctx.seek(topic, partition, msgId);
} catch (UnsupportedOperationException e) {
    log.warn("seek not supported by this context; skipping reset to {}", msgId);
}

try {
    ctx.seek(topic, partition, messageId);
} catch (UnsupportedOperationException e) {
    log.warn("SinkContext.seek unsupported; skipping reposition to {}", messageId);
}

When it happens

Trigger: Calling sinkContext.seek("topic", 0, messageId) in a sink whose runtime SinkContext implementation does not override seek (or running in an environment without seek support).

Common situations: Sink connectors implementing replay/rewind logic; tests using stub contexts; older Pulsar worker versions predating seek support on SinkContext.

Related errors

• Context does not provide SubscriptionType
• BookKeeper client is not available
• Package Management Service is not enabled in the broker.
• Expire message by timestamp is not supported for non-persist
• Expire message by position is not supported for non-persiste

AI-assisted analysis of apache/pulsar@820761864e (2026-09-06). Data as JSON: /api/errors/0d6926c39f0eeda4. Report an issue: GitHub.