My client sockets disconnect with a "ping timeout" reason after a few hours of connection and can't connect again

[maximilien0405]

Hi, i'm having a bit of a issue with my project. I'm building an app that will stay opened at all times in the device, with a non-stop connection through the sockets. However lately, all of my sockets disconnect and can't reconnect. I managed to print some logs from the device and here it is :

As you can see on the screenshot, the socket connection starts at around 1:30 AM and then is disconnectd at 7:30 AM, but manages to reconnect each time until 9:14 where it disconnects and then can't reconnect with the reason "ping timeout".

I'm not sure where is the problem here. I'm using Angular 17 with ngx-socket-io version 4.6.1. In my backend i use NestJS with socket-io 4.7.2.

Since this problem that happend this morning i did theses steps to try to fix the problem (i haven't tried it yet) :

• Upgraded my NestJS from v9 (a year old) to v10 (including the @nestjs/websockets package)
• Upgraded socket-io in my NestJS from 4.7.2 to 4.7.5
• Added a pingTimeout of 60000 to my WebSocketGateway (maybe this will fix it ??)

Any idea what could be causing the problem ? Also it's important to note than in my APP i have an interval that tries to connect to the socket every minute just in case it's disconnected, but as you can see on the logs, it can't even reconnect 🤔

Edit: Also important to note that it's only 4 cuccurent connections. With 1 CPU and 2GB of RAM. With NGINX and PM2 for my API.

@darrachequesne

[darrachequesne]

Hi! That's weird indeed. It seems the client is not even able to reach the server.

Is the server reachable? What happens if you restart the server? nginx? You mention using a device, are you on Android? iOS?

[maximilien0405]

Yes the server is reachable since i can connect it from another device or if i just reload the app. If i restart the server nothing changes, they still can't connect, even though they try to reconnect. It happens on IOS and Android. All of my devices are turned on and the app is open h24
Right now i just added a catch to the "ping timeout" error and added a location.reload() to reload the app and reconnect to the server (hopefully). I will also implement a way to do a location.reload() once a day, just to reconnect to the socket freshly and prevent any timeout problem @darrachequesne

Edit : Also important to note that all of them disconnected at the same time (i have some logs if you need)
Edit 2 : Maybe my error on socket.io-admin-ui is related to the problem ? (socketio/socket.io-admin-ui#86)

[Mpratyush54]

Once try that if you are emitting some random data at fix time interval probably less than 1/2 hrs as it appears that there is a time out error also try connecting it with new devices after this error arises