After you delete a Group in ApsaraMQ for Kafka, message accumulation alerts may persist because the consumer offsets associated with the Group remain on the server. The alerting system monitors these offsets, so alerts continue as long as the offsets exist.
This happens for two reasons:
Offsets persist after deletion. In server-side versions earlier than 2.2.0 (based on Apache Kafka 0.10.2), the Kafka API does not support deleting consumer offsets. Deleting a Group only removes it from the console. The underlying offset data remains on the server.
Consumer threads are still active. Even after you delete a Group, consumer threads may continue running if they were not explicitly stopped. These threads keep committing offsets, which triggers accumulation alerts.
Before you begin
Stop all consumer threads in the Group before you attempt any of the following solutions. An active consumer thread is one that subscribes to messages by using the subscribe method. If any thread is still committing offsets, the alerts persist regardless of other actions.
Solution
Reset consumer offsets
This approach works on all server-side versions and is the fastest way to stop the alerts.
Make sure the Group exists in the console. If you already deleted it, recreate it.
Disconnect all consumer threads.
In the ApsaraMQ for Kafka console, reset the consumer offset to 0 for the partitions where you want to stop tracking message accumulation. For detailed steps, see Reset consumer offsets.
The alerting system stops tracking accumulation for those partitions after the reset.
Delete the Group directly (server-side version 2.2.0 or later)
If your instance runs server-side version 2.2.0 or later and the Group has no active consumer threads, delete the Group directly. The server removes both the Group and its consumer offsets.
If alerts continue after deletion, verify that no consumer threads are still committing offsets.
Wait for offsets to expire (server-side versions earlier than 2.2.0)
On older server-side versions, consumer offsets are automatically cleared after the configured consumer offset retention period expires, provided that no consumer thread updates them. To check or adjust the retention period, see Modify message configurations.
Upgrade the server-side version (server-side versions earlier than 2.2.0)
If the Group has no active consumer threads, upgrade the server-side version to 2.2.0 or later. After the upgrade, recreate the Group and delete it to remove the offsets. For upgrade steps, see Upgrade instance versions.
Disable message accumulation alerts
If none of the preceding solutions resolve the issue, disable the alert rule for message accumulation in CloudMonitor. For details, see CloudMonitor.
In server-side versions 2.2.0 and later, consumer offsets are not deleted as long as the Group has at least one active consumer thread, even if the offsets exceed the consumer offset retention period. For more information, see Why are consumer offsets not deleted after they expire?.