GitHub user berg223 edited a discussion: Should we continue to use ConcurrentLongHashMap in source code?
I have write a [benchmark](https://github.com/berg223/BenchMark/blob/main/src/main/java/apache/pulsar/map/BenchMarkRunner.java) for ConcurrentLongHashMap and ConcurrentHashMap. And the result shows ConcurrentHashMap has at least 1.6x throughput than ConcurrentLongHashMap. However, ConcurrentHashMap do have more gc count. **Do you think it's a tradeoff between throughput and gc count?** I have upload the benchmark result in attachment file [benchmark-concurrent-hashmap.json](https://github.com/user-attachments/files/25598801/benchmark-concurrent-hashmap.json). You can visialize the result in [JMH Visualizer](https://jmh.morethan.io/). And summary the result of throughput benchmark in the following table: <table> <tr><td>method</td> <td>ConcurrentHashMap</td> <td>ConcurrentLongHashMap</td> </tr> <tr><td>getAbsent</td> <td>about 500,000,000 ops/s</td> <td>about 300,000,000 ops/s</td> </tr> <tr><td>getPresent</td> <td>about 500,000,000 ops/s</td> <td>about 300,000,000 ops/s</td> </tr> <tr><td>putAbsent</td> <td>about 14,000,000 ops/s</td> <td> about 5,000,000 ops/s</td> </tr> <tr><td>putPresent</td> <td>about 80,000,000 ops/s</td> <td> about 30,000,000 ops/s</td> </tr> <tr><td>removeAbsent</td> <td>about 220,000,000 ops/s</td> <td> about 33,000,000 ops/s</td> </tr> <tr><td>removePresent</td> <td>about 200,000,000 ops/s</td> <td> about 30,000,000 ops/s</td> </tr> </table> **My question: Is ConcurrentLongHashMap a better choice than ConcurrentHashMap? Should we continue to use ConcurrentLongHashMap in source code?** GitHub link: https://github.com/apache/pulsar/discussions/25271 ---- This is an automatically sent email for [email protected]. To unsubscribe, please send an email to: [email protected]
