Azure App Services Down Since Crowdstrike Incident

Question

We have several app services in our development subscription that are getting 500 errors. This started happening after the CrowdStrike incident. I am not seeing though that app services are affected in the service health announcements. In the log stream of the various app services I am seeing the below errors:

"IIS was not able to access the web.config file for the Web site or application. This can occur if the NTFS permissions are set incorrectly."

"Timeout expired.  The timeout period elapsed prior to obtaining a connection from the pool.  This may have occurred because all pooled connections were in use and max pool size was reached."

I have tried restarted the app services, and I have tried scaling up and scaling down our shared app service plan as well as scaling up and down our SQL elastic pools.

It just seems to be that here has to be some backend problems happening, but I have not heard whispers of this in research.

Our production subscription is on a CSP, and we were directed to let our EA agreement expire on our development subscription because Microsoft does not support development subscriptions on CSP agreements. We are left without support on our dev subscription, and I cannot upgrade the support because we are on an EA. I feel like I am in a cyclical loop of chaos without a way of getting help from Microsoft. I guess my only solace is that it has not affected our production subscription yet.

Answer 1

If I understood well your problem is that several app services in the development subscription are experiencing 500 errors, which began following a CrowdStrike incident. The errors are related to IIS being unable to access the web.config file due to incorrect NTFS permissions and connection pool timeouts caused by all pooled connections being in use.

You may need to verify the NTFS permissions for the web.config file are correctly set so that IIS can access it.

Then, review and adjust the connection pool settings in the connection string to accommodate the necessary number of connections and identify any long-running queries or transactions that may be holding onto connections.

Reach out to Microsoft support, they may help you.