Advanced Web Server Fail-Over & Load Balancing Check
Basic Fail-Over
By default A-Team Systems' front end load balancers (using NginX) keep track of which back end servers are functioning by seeing what HTTP code is returned when it processes a user driven request. In general terms, if a web server is returning 200 (OK) codes with its pages, it believes the peer is functional. If it returns a 500, 501, 502, or 503 it believes the server is having problems, will mark it down internally, and route traffic to a different one.
This works well in th...