如何处理 Azure 应用服务 WebSockets 超时？

Question

I have 2 app services instances set up in Azure, with one connecting to the other through a WebSocket connection. Some of the connections are long-running (multiple minutes) as the processing takes time. After approx. 2 minutes and a few seconds (I assume it's about the 230 second idle timeout Azure has) the connections time out with ECONNTIMEDOUT. Is there any way to circumvent this with WebSockets? Locally, everything works as expected.

Answer 1

The Azure apps have an 'idle timeout.' According to Microsoft, this is usually between 4 and 30 minutes long, after this time, your client's connection is removed.

Apparently, this is configurable.

You should be able to go into the app's config settings ie, app.config for app service and change the idle timeout property on any endpoints you have open on the app like so.

Ex:

<InputEndpoint name="MyEndpoint" protocol="tcp" localPort="80" port="80" idleTimeoutInMinutes="30" />

Answer 2

If its an ASP.Net (Framework) app you can setup a heartbeat message to push down the WebSocket to keep the connection open. .net core also has something similar I believe.

You can use the HttpRuntime.Cache to set this up really easily as Jeff Atwood explains on the Stackoverflow Blog: https://stackoverflow.blog/2008/07/18/easy-background-tasks-in-aspnet/