Hongjiang Zhang

@spmallette What performance implications do you mean here? Do you mean the performance comparison of Collections.synchronizedMap and ConcurrentHashMap? If yes, https://www.baeldung.com/java-synchronizedmap-vs-concurrenthashmap already gives the result.

@xiazcy I cannot reproduce the issue through UT. This only occurs in my production environment. So, If a UT is a must, I do not want to continue invest on...

@spmallette What about applying concurrentlinkedhashmap? Maybe this one: https://github.com/ben-manes/concurrentlinkedhashmap which suggests using caffeine cache. Anyway, let us check whether the concurrentlinkedhashmap can pass the failed case in 3.6-dev.

@spmallette Thanks for your attention on this. Well, for this issue, I did not find other approaches. I have temporarily applied ConcurrentHashMap in my local environment even though it sacrisfied...