On ApsaraMQ for Kafka instances running broker version 0.10.2, deleting a consumer group from the console does not stop message accumulation (consumer lag) alerts for that group.
Apache Kafka versions earlier than 2.0 do not provide the AdminClient API for physically deleting consumer groups. The console performs only a soft delete, so consumer offset data remains in the internal topic __consumer_offsets. Because alerts are driven by consumer offsets, they persist even after the group is removed from the console.
How to fix this
Upgrade to broker version 2.2.0 or later, then recreate the consumer group with the same configuration and delete it again. Version 2.2.0 and later physically remove consumer offset data on deletion. See Upgrade the version of an instance.
Disable the message accumulation alert rules if you no longer need them. See Monitoring and alerting.
Wait for the consumer offset retention period to expire. Consumer offsets in ApsaraMQ for Kafka are stored in the internal topic __consumer_offsets and cannot be deleted directly. If a consumer offset is not updated within the retention period, it is automatically deleted. You can configure the retention period under Change message configurations.
Note: If any consumer thread is still active in the group, the consumer offset is not deleted even after the retention period expires. See Why consumer offset expired but has not been deleted?
Reset the consumer offset to 0. Create a new consumer group and reset the consumer offset of each partition to 0 in the console to clear the accumulated offset data. See Reset consumer offset.
Applicable scope
ApsaraMQ for Kafka