Wait on existing polling request if it takes longer than 2 seconds.

[ahmelsayed]

Small update to ignore timer clicks if there is already an ongoing polling request for logs.

Before I was using a switchMap to cancel the old request if there is a new one due. The problem there is that a new request is always going to be due in 2 seconds, and if the worker is slow or overloaded, it can take more than 2 seconds to get the logs. In that case we will end up in a request/cancel loop and won't be able to catch up.

/cc @davidebbo

[ahmelsayed]

I guess another issue that this has that the previous implementation didn't is if a request is stuck for whatever reason, we will never cancel it. that can be fixed with something like

.switchMap(() => 
        this._functionAppService.getLogs(this.context, this.functionInfo, null, true)
        // if request is done, or it's been 10 seconds
        .merge(Observable.timer(10 * 1000))
        .do(() => ongoingRequest = false))

but I'm not sure if that's worth it.

[davidebbo]

Sure, but if it gets stuck completely, chances are the container is not too healthy. If so, you probably won't be able to run your function, and the lack of logs is irrelevant :)

So I think it's better with your change, but we'll pound on it and see how it works.

[hartra344]