503-error – Row Coding

HAProxy responding with NOSRV while backend is up

November 21, 2022 by Tarik

I notice from the given configuration that you are running infront of an AWS ELB load balancer v2 and I am guessing that v2e points directly to an app server (which would otherwise be behind ELB)? If so this will suggest to me that, along with the 503 error, the connection between your HAProxy instance … Read more

AWS ELB Apache2 503 Service Unavailable: Back-end server is at capacity

August 30, 2022 by Tarik

You will get a “Back-end server is at capacity” when the ELB load balancer performs its health checks and receives a “page not found” (or other simple error) due to a mis-configuration (typically with the NameVirtual host). Try grepping the log files folder using the “ELB-HealthChecker” user agent. e.g. grep ELB-HealthChecker /var/log/httpd/* This will typically … Read more