We have a kafka streams application (2.0) which is communicating with kafka brokers (1.1.0). The streams application has been reprocessing the entire log for no discernible reason - the application hadn't been restarted, wasn't being rebalanced, and was just sitting around - in some cases it was processing messages, in others it was waiting to receive messages (having processed messages less than 6 hours ago). We've done a fair amount of research and have ruled out a potential cause by setting the offset-retention-minutes to 1 week, the same amount of time as our message retention. Additionally, it wouldn't make sense that this would be the root cause of the issue the consumer group offset was reset while it was actively processing messages.
There is nothing interesting in the broker logs around the time of the events:
[2019-02-21 09:02:20,009] INFO [GroupMetadataManager brokerId=2] Removed 0 expired offsets in 0 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2019-02-21 09:12:20,009] INFO [GroupMetadataManager brokerId=2] Removed 0 expired offsets in 0 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2019-02-21 09:12:51,084] INFO [ProducerStateManager partition=MY_TOPIC-1] Writing producer snapshot at offset 422924 (kafka.log.ProducerStateManager)
[2019-02-21 09:12:51,085] INFO [Log partition=MY_TOPIC-1, dir=/data1/kafka] Rolled new log segment at offset 422924 in 1 ms. (kafka.log.Log)
[2019-02-21 09:14:56,384] INFO [ProducerStateManager partition=MY_TOPIC-12] Writing producer snapshot at offset 295610 (kafka.log.ProducerStateManager)
[2019-02-21 09:14:56,384] INFO [Log partition=MY_TOPIC-12, dir=/data1/kafka] Rolled new log segment at offset 295610 in 1 ms. (kafka.log.Log)
[2019-02-21 09:15:19,365] INFO [ProducerStateManager partition=__transaction_state-8] Writing producer snapshot at offset 3939084 (kafka.log.ProducerStateManager)
[2019-02-21 09:15:19,365] INFO [Log partition=__transaction_state-8, dir=/data1/kafka] Rolled new log segment at offset 3939084 in 0 ms. (kafka.log.Log)
[2019-02-21 09:21:26,755] INFO [ProducerStateManager partition=MY_TOPIC-9] Writing producer snapshot at offset 319799 (kafka.log.ProducerStateManager)
[2019-02-21 09:21:26,755] INFO [Log partition=MY_TOPIC-9, dir=/data1/kafka] Rolled new log segment at offset 319799 in 1 ms. (kafka.log.Log)
[2019-02-21 09:22:20,009] INFO [GroupMetadataManager brokerId=2] Removed 0 expired offsets in 0 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2019-02-21 09:23:31,283] INFO [ProducerStateManager partition=__consumer_offsets-17] Writing producer snapshot at offset 47345110 (kafka.log.ProducerStateManager)
[2019-02-21 09:23:31,297] INFO [Log partition=__consumer_offsets-17, dir=/data1/kafka] Rolled new log segment at offset 47345110 in 28 ms. (kafka.log.Log)
And absolutely nothing in the application logs (even with the log level set to DEBUG).
Any ideas about what might be causing this issue?
