We have a MVC5, .NET4.7 app on Azure App Services running with Application Insights.
Today I got a strange error which seemed to force a recyle of the AppPool since 80% of requests was running for more than 200 secs over a 5 min period. It is a standard MS autoheal rule.
The Event Log Error was:
EventID: 1000
Source: Instrumentation Engine
Text: Directory watcher failed with 64
I am assuming an EventId of 1000 means a process/thread crash. However I am not entirely sure what "Instrumentation Engine" relates to. I am assuming Application Insights, and I am even less certain what "Directory watcher failed with 64" means.
My immediate thought was AI was interfering, and had crashed and as a result has crashed my site. Obviously there is a lot going on with AI. Also I noticed that the staging instance was pointing to the same AI instance. Perhaps having 2 instances confused the AI. For now I have stopped the staging instance.
We also use Glimpse and I did see another error "Invalid Program Exception". I am assuming Glimpse(V1,8,6) is compatible with AI.
Thoughts really appreciated, thanks.