Azure App Gateway使用Private LB和Service Fabric返回502

Question

We have a multi-tenant application running on Service Fabric behind a public and private load balancer. Each tenant gets a copy of the app running on a different port in Service Fabric.

Application Gateway is used for SSL offloading to private load balancer with multi-site listener per tenant/app. The application seems to work fine except in this a very odd scenario. There's a double POST followed by a GET. The first POST returns 200 and the second one 302. I think the second one sets a dynamic route that is then called by GET. If you try to manually access the new route you get 404.

Somehow in this bizarre context App Gateway returns 502.

I already tried the following: - Setting a custom probe with a range of 200-599 - Pointing an App Gateway to a single VM (from the SF cluster) - Removing HTTPS configuration - HTTP only

Answer 1

We worked it out. It was a cookie size. The request that was throwing 502 was setting some additional cookie data, making it larger than 4KB