[BUG] Catchup read cause OOM

[superhx]

• Reader thread "stuck on" replacementNode
• HashMap$Node occupies most of the memory, and these Node's incoming references are directly from the thread
• However, the retained heap memory usage of the HashMap itself is not high

Therefore, it is suspected that the deadlock was caused by the concurrent operation of HashMap in multiple threads plus the frantic creation of Nodes within method calls causing OOM.