Jorge Esteban Quilcate Otoya created KAFKA-16229:
----------------------------------------------------
Summary: Slow expiration of Producer IDs leading to high CPU usage
Key: KAFKA-16229
URL: https://issues.apache.org/jira/browse/KAFKA-16229
Project: Kafka
Issue Type: Bug
Reporter: Jorge Esteban Quilcate Otoya
Assignee: Jorge Esteban Quilcate Otoya
Expiration of ProducerIds is implemented with a slow removal of map keys:
```
producers.keySet().removeAll(keys);
```
Unnecessarily going through all producer ids and then throw all expired keys to
be removed.
This leads to exponential time on worst case when most/all keys need to be
removed:
```
Benchmark (numProducerIds) Mode Cnt
Score Error Units
ProducerStateManagerBench.testDeleteExpiringIds 100 avgt 3
9164.043 ± 10647.877 ns/op
ProducerStateManagerBench.testDeleteExpiringIds 1000 avgt 3
341561.093 ± 20283.211 ns/op
ProducerStateManagerBench.testDeleteExpiringIds 10000 avgt 3
44957983.550 ± 9389011.290 ns/op
ProducerStateManagerBench.testDeleteExpiringIds 100000 avgt 3
5683374164.167 ± 1446242131.466 ns/op
```
A simple fix is to use map#remove(key) instead, leading to a more linear growth:
```
Benchmark (numProducerIds) Mode Cnt
Score Error Units
ProducerStateManagerBench.testDeleteExpiringIds 100 avgt 3
5779.056 ± 651.389 ns/op
ProducerStateManagerBench.testDeleteExpiringIds 1000 avgt 3
61430.530 ± 21875.644 ns/op
ProducerStateManagerBench.testDeleteExpiringIds 10000 avgt 3
643887.031 ± 600475.302 ns/op
ProducerStateManagerBench.testDeleteExpiringIds 100000 avgt 3
7741689.539 ± 3218317.079 ns/op
```
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
