As some of you know, one of my passions and area of focus is
on the use of Apache httpd as a reverse proxy and, as such, load
balancing, failover, etc are of vital interest to me.
Thoughts? Ideas? Comments? Suggestions? :)
There are a couple of analogous systems from my former employer that used a "pull from front end queue" concept for load balancing. I thought that was very interesting, although I never had any practical experience servicing those systems.
The idea is that each back end pulls off work as quickly as possible. If one back end is slower/faster than the average, it just does less/more work that the others, and no (bound to fail) clever oracle is required. The downside might be the presence of a front end queue which implies latency. I don't know how such a system would perform when the back ends are only lightly or moderately loaded and the front end queue is usually empty.