gRPC Python server can be closed by "server.stop()". Underlying, the gRPC Python server has a background polling thread. The deallocation of the server object is not directly terminating the polling thread since there is no way to interrupt thread in Python. So, during the server deallocation, it will set a destruction flag, and if the polling thread sees the flag it will terminate itself. It's possible that there are some lag before the server completely shuts down. To eliminate this issue, we recommend you close the server explicitly by "server.stop()" which will block until the server is completely shut down.
Lidi Zheng On Mon, Apr 15, 2019 at 11:09 AM Sidhartha Thota <[email protected]> wrote: > This is known issue afaik. May be your issue is related to this one: > https://github.com/grpc/grpc/issues/9767 > > If the connection is down the session will not be re-useful but channel is > always useful. Here session is individual RPC/Streaming RPC call. So, when > session is in progress and connection is down then session cannot be > restored. Channel is different and maintains connection with other end > (here server) and retries to connect periodically so it takes time to > reconnect to to server. > > > > On Mon, Apr 15, 2019 at 8:49 AM <[email protected]> wrote: > >> Steps to reproduce >> >> 1. Start server >> 2. Send a client RPC to server >> 3. Restart server >> 4. Using the same client, send another RPC. The call will fail >> 5. Send another RPC, this call will success >> >> Also I found that if the server is leave stopped for a long time before >> starting up again, the call in step 5 will return "channel is in state >> TRANSIENT_FAILURE" as well. >> >> Example code: https://github.com/whs/grpc-repro >> (Install from requirements.txt then run main.py) >> >> Expected result >> >> All call should success. >> >> Tested with Python grpcio==1.19.0 server/client and with go-grpc server. >> I tried >> setting grpc.max_connection_age_grace_ms, grpc.max_connection_age_ms, >> grpc.max_connection_idle_ms, grpc.keepalive_time_ms, >> grpc.keepalive_permit_without_calls >> but they doesn't seems to help. >> >> From my own investigation, I believe that gRPC channels doesn't drop >> closed channels and tries to send calls in closed channel. There is also >> TCP RST sent. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "grpc.io" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at https://groups.google.com/group/grpc-io. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/grpc-io/e8465f2b-96f1-4ad1-816f-ee6521595179%40googlegroups.com >> <https://groups.google.com/d/msgid/grpc-io/e8465f2b-96f1-4ad1-816f-ee6521595179%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > > > -- > Thanks, > Sidhartha Thota. > > -- > You received this message because you are subscribed to the Google Groups " > grpc.io" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/grpc-io. > To view this discussion on the web visit > https://groups.google.com/d/msgid/grpc-io/CALguN-Gg0iiDSEUrO-VEOuGu5Mhemc9bZVqxqi_BcY7-pc%3DQWg%40mail.gmail.com > <https://groups.google.com/d/msgid/grpc-io/CALguN-Gg0iiDSEUrO-VEOuGu5Mhemc9bZVqxqi_BcY7-pc%3DQWg%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "grpc.io" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/grpc-io. To view this discussion on the web visit https://groups.google.com/d/msgid/grpc-io/CAMC1%3DjdAO13aORdiXSv2R%3DVYRmTHQHkd9Di3nXztKwYSPvQfwQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
