Linux – High Availability Configuration using Heartbeat and Pacemaker

To remove the single point of failure, you can do one of the following:

1- Remove the load balancer entirely and configure the servers to work in active-passive mode. You can use heartbeat package for Linux to do it. In this case, you lose the processing power of one machine and use only one as a fail-over!

2- Install and configure another load balancer. The two load balancers will work in active-passive mode. Also, heartbeat can be configured on both servers (I am assuming Linux-based load balancers). This is a bit more expensive as it requires a new system.

3- Install the two load balancers on the same debian systems. So, you don't need to install a new system. However, this may not be recommended as it complicates the systems and mixes more services on the same server (the server already works as web server and DB server).

My understanding is that haproxy is a load balancer, the benefits of which are scaling and redundancy NOT performance.

To bench the effects of your load balancer you should run you should first bench the faster of your servers, increasing the load until you find the point at which it falls apart. Then start at that point when you bench haproxy, you should be able to handle approximately twice the amount of connections.

To increase the speed you want a caching reverse proxy such as nginx, varnish or squid.