I have an application gateway with tier WAF V2, Capacity type: Manual, Instance count: 2, it has 2 backend app services.
Earlier when I was using directly the app services url to access the applications it was working faster, but after integration of application gateway before the app services the performance of the application has reduced drastically, and many times it gives error 504 Gateway time out.
The configuration of custom health probe is:
interval seconds: 30
timeout seconds: 300
unhealthy threshold: 3
http response status code match: 200-399, 404