Static topic mapping may select a stale epoch when the epoch delta overflows

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Assessment

Difficulty
2/5
Estimated time
1-3 hours
Newbie friendliness
78/100
Issue type
Bug
Clarity
Clearly specified
Activity status
Quiet
Tech stack
java
Domain
distributed-systems

Research direction

Start at checkAndBuildMappingItems and trace the replacement-mode ordering of mapping details for the same logical queue. Reproduce the issue with epochs 0 and Long.MAX_VALUE, then verify that the latest epoch is selected without overflow and add or run a regression check for that behavior.

Written by the indexing model from the issue text.

Description

Description

Static topic mapping sorts long epoch values by subtracting them and narrowing the result to int. When two epochs differ by more than Integer.MAX_VALUE, the comparator can reverse their order. In replacement mode, checkAndBuildMappingItems then keeps the stale broker mapping instead of the latest one.

Expected behavior

Epochs should be ordered with Long.compare so the newest mapping always wins without arithmetic overflow.

Reproduction

Create two mapping details for the same logical queue with epochs 0 and Long.MAX_VALUE, call checkAndBuildMappingItems with replace enabled, and observe that the epoch-0 mapping is selected.

Dominant language
Java
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Forks
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Avg merge
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Merged PRs (30d)
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