Hi,
one of our customers tells us about strange behavior:
Our webapp closes the connection to the clients sometimes.
The customer has about 20 employees working with our webapp. When we open the app, we never loose the connection.
What reasons can this have?
One possibility is how busy the users are. The busier they are, the more connections there are. By default web apps are set for 200 simultaneous connections which equates to about 50 users.
It could also just be a processing issue. If you’ve got a routine that uses lots of cpu cycles, users could get disconnected just because a connection times out.
Does it close everyone out at the same time? or is it one user that has this problem?
[quote=346057:@Lars Lehmann]Hi,
What reasons can this have?[/quote]
Perhaps a bad Wi-Fi connection? I have that problem, when the users lost just for a second the wi-fi signal, the web-app in the browser closes.
It’s, as far as I can say, more or less randomly.
We allow 400 sim. connections.
Most time there are no cpu stressing tasks and sometimes they do nothing in the app and it closes after seconds with no user action.
They are connected via ethernet with a very stable connection.
How can I see how many connections are used?
you would need to look at the Runtime object and count the number of WebThread objects in use minus any that you were using, but the counting of such objects will be CPU intensive and could cause more issues. [quote=346258:@Lars Lehmann]Most time there are no cpu stressing tasks and sometimes they do nothing in the app and it closes after seconds with no user action.[/quote]
It would be helpful to qualify that. Knowing if we’re talking about five seconds or thirty seconds makes a big difference here.
Now when you say “closes the connection” do they get the disconnect screen?
Sometimes 30 sec, sometimes also 4-5 min. It seems randomly, there are no specific user actions or computing tasks behind.
Exactly.
No ideas? 
The only thing that comes to mind is that modern browsers sometimes “sleep” when there’s been no user activity for a while. When that happens, the telemetry that tells the server that the client is still there disappears and the server assumes it’s gone.
Besides that there’s not enough information.
I think this couldn’t be the reason, because the app sometimes closes even when the user is still working.
Do you catch the App.UnhandledException event?
Yes, no exceptions.