What is Kafka's log retention and cleanup policies?

Kafka supports two cleanup policies:

1. Delete policy (cleanup.policy=delete):

• Deletes old log segments based on time/size
• log.retention.hours=168 (7 days default)
• log.retention.bytes=-1 (unlimited size default)
• log.segment.bytes=1GB (segment size)

2. Compact policy (cleanup.policy=compact):

• Keeps the latest value for each key
• Useful for changelog topics
• Background compaction process
• Maintains ordering within partitions

Combined policy:

cleanup.policy=compact,delete
# Both compaction and time-based deletion

Monitoring: Track log size and compaction metrics to ensure proper cleanup.