Socket connection disconnects

[TannerGabriel]

I'm running an application with a Javascript socketio server and Python socketio client and the client is disconnecting quite often (about 100 times per hour) without any obvious reason. Since the disconnect function does not send any information on why the disconnect happened, I enabled the logger and received the following error:

{"log":"Waiting for write loop task to end\n","stream":"stderr","time":"2022-12-16T00:59:54.035591184Z"}
{"log":"Exiting write loop task\n","stream":"stderr","time":"2022-12-16T00:59:54.061058204Z"}
{"log":"Engine.IO connection dropped\n","stream":"stderr","time":"2022-12-16T00:59:54.086687114Z"}
{"log":"2022-12-16 00:59:54,086 [_main_    ] INFO     Socket Client disconnected!\n","stream":"stderr","time":"2022-12-16T00:59:54.086747132Z"}

I also enabled the debug statements for the Socket server:

2022-12-15T09:51:58.125Z socket.io:client client close with reason transport close

Below is a list of what I have already tried to fix the issue. Is there anything else I can do/try?

Already tried

• Different combination of versions (latest for everything, older versions that have worked for me in the past)
• Changing Socket timeout
• Nginx timeout debugging

[miguelgrinberg]

Have you enabled low level logs in the client? The option is engineio_logger=True. I can't really suggest anything since there are no clues in the log snippets that you have shared. Also, does this problem occur when connecting to your server with one of the example clients in this repository?

[TannerGabriel]

Sorry for the confusion. I tried the same code on different setups with different network connections (e.g., two VPS, two local servers, etc.) and the only time the problem occurred was when connecting over a domain with the above Nginx setup.

I fully understand if that is not something you can help me with. Therefore you can see this discussion as resolved, but I will still post the solution to my problem once found. Thank you for your help!

[miguelgrinberg]

I'm sorry but to make this crystal clear for me, can you tell me if you reproduced this error when connecting over wi-fi or wiref connection? Knowing if this happens only on mobile networking is important.

[TannerGabriel]

Yes, I reproduced the error using two VPS servers (client and server; both have ethernet connection in a server center), so it does not only happen on mobile. Furthermore, the application with UMTS connection also works without the Nginx config + Domain.

I could provide a minimal repository to reproduce the bug/error if that would be helpful.

[miguelgrinberg]

Yes, please. Thank you.

[TannerGabriel]

Sorry for the wait. As described in the README, you will have to test it using HTTPS with a domain. https://github.com/TannerGabriel/python-socketio-error

If you have any questions, please don't hesitate to contact me.