There are multiple types of failures in an application:
- network
- machine
- database
- application
In case of application failure specifically, it is possible that a different server might be able to serve the request successfully. For instance, request to a/ crashed the server but b/ would work fine. But if request to B was directed to that particular server right after request to A, then it'd fail.
So given that, is it possible to have the load balancer try again with a different instance in case of error or time out.
I've confirmed ELB doesn't. But is there a load balancer that does?