[blazor] fix multiple calls to OnConnectionDownAsync #62518
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| if (this.Client.Connected) | ||
| { | ||
| await OnConnectionDownAsync(CancellationToken.None); | ||
| } |
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I don't think this is the right change to fix the metric issue. It's changing an existing behavior of the system that users might be relying on.
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this event is called twice. That's a bug not a feature
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What is causing the 2nd call?
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The proper event is Hub.OnDisconnect()
CircuitHost.OnConnectionDownAsync() is called from CircuitHost.DisposeAsync() regardless if it's connected or not, creating dis-balance.
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@javiercn does this make sense or you have another proposal for the fix ?
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I just tested the "close tab" and "navigate to non-interactive page". Both behave as expected, that is, they call the event once.
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Terminate it's not being fired in those cases.
- Close tab will likely don't cause
unloadto fire. navigate to non-interactive page- It takes a bit of time for the client to start the circuit disposal.
- If for some reason it's not happening, it's also a bug.
If we check for the circuit to be connected it won't fire when we want to eagerly terminate the circuit.
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Maybe we need to call that event from places that call circuitHost.Client.SetDisconnected() rather than relying that circuitHost.DisposeAsync() would always call it.
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Also I'm not sure that the new PauseAndDisposeCircuitHost is calling SetDisconnected()
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I made the calls to OnConnectionDownAsync more explicit now, instead of relying on the DisposeAsync.
@javiercn please review again.
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Rather than restructure the code in the current way. Isn't it simpler and safer to make OnConnectionDown "idempotent"? Keeping a flag when you run it and resetting it with OnConnectionUp.
That way we save ourselves the trouble of having to worry about when OnConnectionDown should run and the change is localized into a single file and can be easily tested.
I worry that the current approach introduces subtle behavior changes and require us to carefully consider the correctness of all the locations where we are now explicitly handling the callbacks.
Also the If we rather introduce a new flag, should it be
Do you mean that we only fire
In other words, do you want to fix double-firing of Anyway, I'll give it a try with a new flag and I'll improve the fix for |
CircuitHost.OnConnectionDownAsync()fromCircuitHost.DisposeAsync()if it's not connected_circuitConnectedCounter.AddfromCircuitMetrics.OnCircuitDownFixes #62219