GLB (Galera Load Balancer) is a simple TCP connection balancer made with scalability and performance in mind. It was inspired by pen, but unlike pen its functionality is limited only to balancing generic TCP connections.
glb is beta software. That is it seems to be feature complete, but was not tested extensively. It was developed and tested on Linux, but theoretically should work on any system that has POSIX threads and poll().
Here are some key features of "GLB":
· list of backend servers is configurable in runtime.
· supports server "draining", i.e. does not allocate new connections to server, but does not kill existing ones, waiting for them to end gracefully.
· on Linux 2.6 and higher glb uses epoll API for ultimate performance.
· glb is multithreaded, so it can utilize multiple CPU cores. In fact even on a single core CPU using several threads can significantly improve performance when using poll()-based IO.
· connections are distributed proportionally to weights assigned to backend servers.