[GitHub] [kafka] hachikuji commented on a change in pull request #9332: KAFKA-10511; Ensure monotonic start epoch/offset updates in `MockLog`

[GitBox <gi...@apache.org>]

hachikuji commented on a change in pull request #9332:
URL: https://github.com/apache/kafka/pull/9332#discussion_r494494327



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File path: raft/src/test/java/org/apache/kafka/raft/MockLog.java
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@@ -310,10 +310,10 @@ public LogFetchInfo read(long startOffset, Isolation isolation) {
     }
 
     @Override
-    public void assignEpochStartOffset(int epoch, long startOffset) {
-        if (startOffset != endOffset().offset)
-            throw new IllegalArgumentException(
-                "Can only assign epoch for the end offset " + endOffset().offset + ", but get offset " + startOffset);
+    public void initializeLeaderEpoch(int epoch) {
+        long startOffset = endOffset().offset;
+        epochStartOffsets.removeIf(epochStartOffset ->

Review comment:
       There's no guarantee that the leader change message ever gets committed. It is even possible for the leadership to change multiple times before a leader change message can be committed. There is no correctness problem with the current implementation. I just wanted the behavior to be consistent with `LeaderEpochFileCache`.




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