KRaft - Kafka nodes continuously generating metadata deltas from snapshots

[techjourney010]

Description
As Kafka cluster starts running in KRaft mode, the Kafka nodes continuously generates metadata from the shapshots.

I don't know if it is an issue, I want to be sure that this is how often it should happen.

Troubleshooting

Check out partial logs:
2023-05-22 11:58:13 kafka1 | [2023-05-22 08:58:13,524] INFO [MetadataLoader 1] handleSnapshot: generated a metadata delta from a snapshot at offset 47311 in 7 us. (org.apache.kafka.image.loader.MetadataLoader) 2023-05-22 11:58:13 kafka2 | [2023-05-22 08:58:13,525] INFO [MetadataLoader 2] handleSnapshot: generated a metadata delta from a snapshot at offset 47312 in 8 us. (org.apache.kafka.image.loader.MetadataLoader) 2023-05-22 11:58:14 kafka1 | [2023-05-22 08:58:14,028] INFO [MetadataLoader 1] handleSnapshot: generated a metadata delta from a snapshot at offset 47312 in 15 us. (org.apache.kafka.image.loader.MetadataLoader) 2023-05-22 11:58:14 kafka3 | [2023-05-22 08:58:14,028] INFO [MetadataLoader 3] handleSnapshot: generated a metadata delta from a snapshot at offset 47312 in 19 us. (org.apache.kafka.image.loader.MetadataLoader) 2023-05-22 11:58:14 kafka2 | [2023-05-22 08:58:14,030] INFO [MetadataLoader 2] handleSnapshot: generated a metadata delta from a snapshot at offset 47313 in 9 us. (org.apache.kafka.image.loader.MetadataLoader) 2023-05-22 11:58:14 kafka1 | [2023-05-22 08:58:14,528] INFO [MetadataLoader 1] handleSnapshot: generated a metadata delta from a snapshot at offset 47313 in 35 us. (org.apache.kafka.image.loader.MetadataLoader) 2023-05-22 11:58:14 kafka3 | [2023-05-22 08:58:14,529] INFO [MetadataLoader 3] handleSnapshot: generated a metadata delta from a snapshot at offset 47313 in 46 us.

Environment

• The setup: here
• Operating System: Windows 10
• Version of Docker: v20.10.23
• Version of Docker Compose: 3

[cptmacp]

same issue here ( with tag 7.4.0 + )

However works fine with 7.3.0 tag ( where env CLUSTER_ID is not req to be specified )

[techjourney010]

Keep in mind that the oppened "issue" might not be an issue. I only need a confirmation that it is ok for the deltas to be that often generated.
Regarding the CLUSTER_ID, it is a mandatory property that each broker registers with. So it must be set in order to operate in KRaft mode.

[treykasada]

Also hit this today. Also not sure if it's a problem. 😅

In case it's helpful for anyone, you can silence these logs by setting KAFKA_LOG4J_LOGGERS='org.apache.kafka.image.loader.MetadataLoader=WARN'.

[mtfash]

Having the same issue