Many high performance systems may use multiple layers of load balancing. Software load balancing is another layer that ensures high performance and low latency.

There are many different software load balancers and open-source solutions are very popular. Some of them are:


Used primarily as a lightweight HTTP server, nginx can also be used as an HTTP load balancer. nginx provides a lot of built-in features, including caching and file serving.



Advertised as “The Reliable, High Performance TCP/HTTP Load Balancer” HAProxy is actually a general TCP load balancer with added features for HTTP. It can serve multiple MySQL or caching servers. HAProxy can scale extremely well.



Pound is a lightweight HTTP-only load balancer. It offers the following features: a reverse-proxy, load balancing, SSL wrapping, HTTP/HTTPS sanitizing, fail over-server, request redirection.



Used as a reverse proxy cache, Varnish also includes functionality to act as a load balancer.

Although software load balancers are useful, they cannot compete with professional performance solutions.