SignalR connection gets terminated after 5 minutes in Chrome

[mgazell]

I'm facing an issue maintaining a signalR connection using the @microsoft/signalr client package. After establishing a connection and 5 minutes of tab inactivity (user active in another tab or window), the connection gets closed. This seems to be related to recent policy changes in Chrome (JavaScript throttling) forcing WebSocket connection termination in 5 minutes of tab inactivity.

You can reproduce this issue using this serverless signalR sample at docs.microsoft.com

The only change that I did on the sample was to change the reference from @aspnet/signalr to @microsoft-signalR in the index.html file

<script src="https://cdn.jsdelivr.net/npm/@aspnet/signalr@1.0.3/dist/browser/signalr.js"></script>

<script src="https://cdnjs.cloudflare.com/ajax/libs/microsoft-signalr/5.0.3/signalr.min.js"></script>

Please see snip from my console below.

[BrennanConroy]

I can't repro this issue, what OS are you on? What version is the OS? Did you make any more modifications to the app?

[mgazell]

I'm on Windows 10 (version 1709) and using Chrome (Version 89.0.4389.90 (Official Build) (64-bit))

No, I didn't make any other change other than the script reference change that I highlighted.

[Davilink]

I can't repro this issue, what OS are you on? What version is the OS? Did you make any more modifications to the app?

I was able to reproduce this issue with Chrome on Windows like every single time:

1. Open a tab using signalr with websocket
2. Wait for the connection to be established
3. Switch a tab
4. Minimize Chrome
5. Wait 5 minutes (10 minutes to be sure)
6. Go back to the original tab
7. Websocket is disconnected

I try to reproduce it on Chrome Linux, but i was under the impression that wasn't reproducible under Linux, but i did...only 1 time, and i cannot reproduce it anymore... (really strange), but on Chrome Windows it's every time.

Other reproduce step:
SignalR/SignalR#4536 (comment)

[Davilink]

Workaround using the « Page Visibility Api » (https://developer.mozilla.org/en-US/docs/Web/API/Page_Visibility_API)

const connection: HubConnection = new HubConnectionBuilder()
  .withUrl('/hub/MyHub')
  .build();

document.AddEventListener('visibilitychange', () => {
  if (document.visibilityState === 'visible' && connection.state !== HubConnectionState.Connected) {
    connection.start();
  }
}

Note: This workaround will not work for all use case because you lose data when the connection is drop. Other thing to take into consideration is the fact that it's a new connection, so if you are using groups, you will need to resubscribe to the group

[IanYates]

Workaround using the « Page Visibility Api » (https://developer.mozilla.org/en-US/docs/Web/API/Page_Visibility_API)

const connection: HubConnection = new HubConnectionBuilder()
  .withUrl('/hub/MyHub')
  .build();

document.AddEventListener('visibilitychange', () => {
  if (document.visibilityState === 'visible' && connection.state !== HubConnectionState.Connected) {
    connection.start();
  }
}

Note: This workaround will not work for all use case because you lose data when the connection is drop.

Good point about the data loss, but it's at least helpful to have the notification of the issue so we might be able to tell the user to expect issues. Thanks!

[mgazell]

Hi @BrennanConroy ,

Are you still not able to repro the issue? Please let me know if you need more inputs.

[Vikki123]

We are also facing the same issue. We are also seeing the same behavior once the tab is minimized for 5 mins. We do not support re-connect option as its not feasible for the use case. Any workaround to keep the ping alive ?.

We are using @microsoft/signalr": "3.1.2

[prasadmamidi7]

I am also facing same problem

Use case

• Create asp.net core singlar core application as backend app
• Create angular app as frontend app
• Go with default values for ClientTimeoutInterval (30sec) and KeepAliveInterval (15sec)
• Launch angular app on chrome browser , miminize the browser for 7 mins
• Signalr Hub will get OnDisconnectedAsync on backend app and websocket connection is closed.

Application version

Chrome Browser: Version 89.0.4389.90 (Official Build) (64-bit)
Asp.net core : 3.1.2
Angular -signalr core :3.1.2

Note: this behaviour is not observed on Microsoft Edge and Firefox .

Any workaround much appreciated.

[BrennanConroy]

Are you still not able to repro the issue?

Still can't repro, We have a rough idea of where there could be an issue with the library with the new Chrome "feature", so we'll try to figure something out there. And probably rely on the community to test it out :)

Any workaround much appreciated.

A workaround would probably be to change the server-side and client-side timeout values to be over 1 minute.

[Vikki123]

@BrennanConroy I quite dint understand how increasing the timeout to 1min would solve this issue. Isnt it going to fail anyways after one min as the connection is disconnected already due to inactivity.?