[jira] [Commented] (KAFKA-19474) Wrong placement of WARN log for truncation below HWM

["Rajani Karuturi (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/KAFKA-19474?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18003710#comment-18003710 ] 

Rajani Karuturi commented on KAFKA-19474:
-----------------------------------------

created a PR https://github.com/apache/kafka/pull/20125 for the fix 
Also added a test to test a scenario where HWM is changed

> Wrong placement of WARN log for truncation below HWM
> ----------------------------------------------------
>
>                 Key: KAFKA-19474
>                 URL: https://issues.apache.org/jira/browse/KAFKA-19474
>             Project: Kafka
>          Issue Type: Bug
>          Components: core
>    Affects Versions: 2.1.0, 4.0.0, 4.1.0
>            Reporter: Gaurav Narula
>            Assignee: Gaurav Narula
>            Priority: Major
>
> {{ReplicaFetcherThread#truncate}} has a useful [WARN log|https://github.com/apache/kafka/blob/da4fbba2793528e283458e080a690ad141857b0b/core/src/main/scala/kafka/server/ReplicaFetcherThread.scala#L171] when a follower is truncating its log segment below its HWM.
> This is of particular help when debugging data loss scenarios like those described in the motivation for [KIP-966|https://cwiki.apache.org/confluence/display/KAFKA/KIP-966%3A+Eligible+Leader+Replicas].
> Unfortunately, a refactoring in [PR 5608|https://github.com/apache/kafka/pull/5608/files#diff-693a5eaaaa4fe61a18af23d5b06ccc024261dda01558cbaacb7020e1911c6d55R264] moved the check to _after_ the truncation, which may modify the HWM. As a result, the log may not be emitted even though the log is truncated below the HWM



--
This message was sent by Atlassian Jira
(v8.20.10#820010)