Azure. the system memory and CPU change cause slowdown our app respond?

Question

Hello, we had a problem at 24th of February between 12:35 and 12:50 (pm by utc). Our app starts to respond slowly and it led to failures, but our app didn’t overload

Could the system memory and CPU change cause a slowdown our app respond? If yes, then how can avoid this problem next time?
There is a screenshot of our app slowdown chart:
In this time we detect change in physical memory and CPU ,

Availability and Performance tools detected top 5 slow request execution. It is requests from our app service to external services. Could these requests the overall performance of the app service or app service plan?

We have app service plan: P2V2.
We have 2 apps and one cluster.

Answer 1

Thanks for asking question! There could be multiple factors which may contribute to slow app performance.

Could you confirm on which app service plan you are using and how many instances you are running and how many webapps are present in the same app service plan.

Also, you may want to know that by default, web apps are unloaded if they are idle for a set period of time. This way, the system can conserve resources. The downside is that the response to the first request after the web app is unloaded is longer, to allow the web app to load and start serving responses. In Basic and Standard service plans, you can turn on the Always On setting to keep the app always loaded. This eliminates longer load times after the app is idle.

You can do that from portal.azure.com -> your site's blade -> All Settings -> Application Settings -> General settings > Always On

See here for details: https://azure.microsoft.com/en-us/documentation/articles/web-sites-configure/

For detailed troubleshooting steps, see Troubleshoot slow web app performance.

Check https://learn.microsoft.com/en-us/azure/app-service/web-sites-monitor might be helpful.

Please let us know If issue persists.