[fix][broker] Fix hash collision when using a consumer name that ends with a number #22053
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merlimat
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👍 In the end, there would always be the possibility of conflict, though it would not impair the correctness. Even if we have 2 different keys hashing to the same bucket, one or the other consumer will get the messages, and with 100 points even few conflict shouldn't be skewing the assignments significantly.
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… with a number (apache#22053) (cherry picked from commit ae2299c)
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… with a number (apache#22053) (cherry picked from commit ae2299c)
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Fixes #22050
Motivation
See #22050, there's a hash collision in ConsistentHashingStickyKeyConsumerSelector when the consumer name ends with a number for example "consumer1" and "consumer11" would collide for the key "consumer111" (consumer1, i=11 & consumer11, i=1).
Modifications
Fix hash collision by adding a separator between the 2 fields used in the hash calculation. Use the NUL character (
\0) as a separator.Documentation
docdoc-requireddoc-not-neededdoc-complete