Is log cleaner logging anything on AWS MSK?

Question

I use AWS MSK cluster with brokers logging turned on to CloudWatch. I can see brokers logs. We have some topics with cleanup.policy=compact and some with cleanup.policy=delete. The system is running on the new cluster for about 2 weeks now.

From my research (e.g. https://zendesk.engineering/an-investigation-into-kafka-log-compaction-5e520f4291f0) I see that kafka should run log cleaner (obviously) and there should be some traces in logs of this activity. However in my CloudWatch log group I cannot find a word "cleaner" or "cleaned" and I cannot find any trace of log cleaner running.

Is it something wrong with my logging settings? Or is log cleaner not running at all (this is suspicious, because we have a lot of messages eligible for cleanup but still not cleaned)?

Answer

Hello there, in order to verify from the logs whether files related to partitions are getting deleted or not you can look for the something similar as below

```
Deleted log LOG_DIR//00000000022134078627.log.deleted
Deleted time index LOG_DIR//00000000022134078627.timeindex.deleted
```

When retention kicks in you will be noticing deletion of log and time index files in the broker logs. That indicates retention is successfully triggered and deleted old log segments.

Is log cleaner logging anything on AWS MSK?

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