We have quite a high traffic, php intensive site; process quite large chunks of data which get cached.
I admit, i'm terrible to commit to change with server configs.
But we need a new, failover solution.
We have tried Nginx+PHP5-FPM in the past and found it threw too many 50x errors. Believe or not we still run Apache+mod_php, APC and memcache and it's stable and reliable.
However we need better fail over and eventually off site redundancy. Don't mention the Amazon Cloud, we didnt get on too well with that either.
So for someone like myself, risk adverse to changing a config / set up that i know yields good performance for our web app how do i introduce the right load balancer?
Essentially 2 load balancers in cluster running heartbeat for eliminate that single point of failure. Load Balancing several web boxes in case 1 or 2 break.
But what LB is stable to use. I like the sound of Zen Load Balancer but i'm also drawn to varnish to reverse proxy and also balance the traffic.
We have a rackspace set up with a LB on another project and it gives us grief, so i just need a stable solution that will LB / failover without any dropped connections or 500 errors.