SpecFlow Visual Studio integration hanging Visual Studio waiting on telemetry to be flushed to the network

[davkean]

SpecFlow Version

Unknown

Test Runner Version Number

Unknown

Issue Description

I'm from the Visual Studio performance team and our telemetry is showing that that SpecFlow VS integration is hanging Visual Studio while it sends and flushes telemetry. This is preventing users from interacting with VS while this code is running.

Over the past 21 days, it has had the following impact on Visual Studio:

Root	Leaf	Expressed Hits	Total Hits	Duration (75th Percentile)	Delayed Mouse Clicks	Delayed Key Strokes
techtalk.specflow.visualstudiointegration.dll!TechTalk.SpecFlow.VsIntegration.SpecFlowPackagePackage.InitializeAsync	microsoft.applicationinsights.dll!Microsoft.ApplicationInsights.Channel.InMemoryTransmitter.DequeueAndSend	2739	4717	4.8 sec	2710	32

Expressed delays are situations where the UI hung while within this method and it interrupted/prevented users mouse or keyboard input. Total hits are all the times the UI hung while within this method, regardless of whether input was interrupted.

There are many call stacks that trigger this failure however, they all contain the the following frames:

chtalk.specflow.visualstudiointegration.dll!TechTalk.SpecFlow.VsIntegration.SpecFlowPackagePackage.InitializeAsync
-> mscorlib!System.Runtime.CompilerServices.AsyncTaskMethodBuilder.Start
--> techtalk.specflow.visualstudiointegration.dll!TechTalk.SpecFlow.VsIntegration.SpecFlowPackagePackage+<InitializeAsync>d__.MoveNext
---> techtalk.specflow.ideintegration.dll!TechTalk.SpecFlow.IdeIntegration.Install.InstallServices.OnPackageLoad
----> techtalk.specflow.vsintegration.implementation.dll!TechTalk.SpecFlow.VsIntegration.Implementation.Analytics.AnalyticsTransmitter.TransmitExtensionLoadedEvent
-----> techtalk.specflow.vsintegration.implementation.dll!TechTalk.SpecFlow.VsIntegration.Implementation.Analytics.AnalyticsTransmitter.Execute
------> techtalk.specflow.vsintegration.implementation.dll!TechTalk.SpecFlow.VsIntegration.Implementation.Analytics.AppInsightsAnalyticsTransmitterSink.TransmitEvent
-------> microsoft.applicationinsights.dll!Microsoft.ApplicationInsights.Channel.InMemoryChannel.Flush
--------> microsoft.applicationinsights.dll!Microsoft.ApplicationInsights.Channel.InMemoryTransmitter.Flush
---------> microsoft.applicationinsights.dll!Microsoft.ApplicationInsights.Channel.InMemoryTransmitter.DequeueAndSend

To fix this issue, please avoid Flushing the AppInsights channel on the UI thread and/or blocking on it, for example:

Task.Run(() => channel.Flush()).Forget();

Steps to Reproduce

This data comes our telemetry system, so we do not have any information on the versions of SpecFlow or any dlls involved in this problem. We also have no understanding of the steps involved to reproduce the above situation other than the fact this data was just captured from real world usage.

Link to Repro Project

No response

[SabotageAndi]

Thanks for the issue report. We will have a look at it. With the stack trace it should be not that hard to find the issue.

[davkean]

@SabotageAndi We found a bunch more stacks and they all in AppInsightsAnalyticsTransmitterSink.TransmitEvent, so be sure to find all direct and indirect callers of it.