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Igal Shilman commented on FLINK-19515: -------------------------------------- Hi, I think that you are correct, and it does seems like a bug. The InvocationContext should be created in __call__ instead of the constructor. This also has to happen in the regular RequestRelplyHander. Would you like to create a PR with the fix? > Async RequestReply handler concurrency bug > ------------------------------------------ > > Key: FLINK-19515 > URL: https://issues.apache.org/jira/browse/FLINK-19515 > Project: Flink > Issue Type: Bug > Affects Versions: statefun-2.2.0 > Reporter: Frans King > Priority: Minor > > Async RequestReply handler implemented in > https://issues.apache.org/jira/browse/FLINK-18518 has a concurrency problem. > > Lines 151 to 152 of > [https://github.com/apache/flink-statefun/blob/master/statefun-python-sdk/statefun/request_reply.py] > The coro is awaiting and may yield. Another coro may continue that was > yielding and call ic.complete() which sets the ic.context to None > > In short: > > {code:java} > ic.setup(request_bytes) > await self.handle_invocation(ic) > return ic.complete() > > {code} > Needs to happen atomically. > > I worked around this by creating an AsyncRequestReplyHandler for each request. > > It should be possible to re-produce this by putting an await asyncio.sleep(5) > in the greeter example and then run in gunicorn with a single asyncio > thread/event loop (-w 1). > > > > {code:java} > response_data = await handler(request_data) > File > "/home/pi/.local/lib/python3.7/site-packages/statefun/request_reply.py", line > 152, in __call__ > return ic.complete() > File > "/home/pi/.local/lib/python3.7/site-packages/statefun/request_reply.py", line > 57, in complete > self.add_mutations(context, invocation_result) > File > "/home/pi/.local/lib/python3.7/site-packages/statefun/request_reply.py", line > 82, in add_mutations > for name, handle in context.states.items(): > AttributeError: 'NoneType' object has no attribute 'states' > {code} > -- This message was sent by Atlassian Jira (v8.3.4#803005)