@Koteswara Pentakota , Apologies you're experiencing timeout and performance issues. To better assist you on this, kindly share the following info:
Were there any changes prior to this issue or it’s always been this way since the WebApp deployment?
Do you have an Application Gateway (AGw) in between this App Service WebApp?
What App Service Plan (ASP)? If you’re using, AGw, is it AGw v1 or v2 SKU?
Just as quick test, if you’re running a lower ASP tier, scale-up your ASP to Standard tier and then test your WebApp for some time. After the test, you may lower your ASP tier, as necessary.
If you haven’t done this already, kindly review these logs to further isolate the issue:
- You may leverage App Service diagnostics from Azure Portal> Navigate to your App Service app in the Azure Portal.
--In the left navigation, click on Diagnose and solve problems – Checkout the tile for “Diagnostic Tools” > “Availability and Performance” & "Best Practices" and review to fetch additional information to isolate further. - You may enable logs from Azure Portal (App Service logs blade) to fetch more pointers on the error. You may enable these logs–
Application logging
,Web Server logging
,Detailed Error Messages
--Kindly checkout the process here - >>Enable diagnostics logging for apps in Azure App Service