zhijiang created FLINK-10367:
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Summary: Avoid recursion stack overflow during releasing
SingleInputGate
Key: FLINK-10367
URL: https://issues.apache.org/jira/browse/FLINK-10367
Project: Flink
Issue Type: Improvement
Components: Network
Affects Versions: 1.6.0, 1.5.3, 1.5.2, 1.5.1, 1.5.0
Reporter: zhijiang
Assignee: zhijiang
For task failure or canceling, the {{SingleInputGate#releaseAllResources}} will
be invoked before task exits.
In the process of {{SingleInputGate#releaseAllResources}}, we first loop to
release all the input channels, then destroy the {{BufferPool}}. For
{{RemoteInputChannel#releaseAllResources}}, it will return floating buffers to
the {{BufferPool }}which will assign this recycled buffer to the other
listeners ( {{RemoteInputChannel}}).
It may exist recursive call in this process. If the listener is already
released before, it will directly recycle this buffer to the {{BufferPool
}}again, then {{BufferPool}} takes another listener to notify available buffer.
The above process may be invoked repeatedly in recursive way.
If there are many input channels as listeners in the {{BufferPool}}, it will
cause {{StackOverflow}} error because of recursion. And in our testing job, the
scale of 10,000 input channels ever caused this error.
I think of two ways for solving this potential problem:
# When the input channel is released, it should notify the {{BufferPool}} of
unregistering this listener, otherwise it is inconsistent between them.
# {{SingleInputGate}} should destroy the {{BufferPool}} first, then loop to
release all the internal input channels. To do so, all the listeners in
{{BufferPool}} will be removed during destroying, and the input channel will
not have further interactions during {{RemoteInputChannel#releaseAllResources}}.
I prefer the second way to solve this problem, because we do not want to expand
another interface method for removing buffer listener, further currently the
internal data structure in {{BufferPool}} can not support remove a listener
directly.
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