Simple DIY Linux/BSD based Network Balancers?

millisa asks: "I've been looking into options for inexpensive web based load balancing services for both Apache and IIS based web servers. There are plenty of commercial products out there that claim to do the job, but they are often too pricey, offer too many features, or are unreliable. I have lost the small amount of confidence I had in the MS based NLB services and do not like the idea of running multiple services on the same system anyways. I would like to build one (or more) simple front end load balancing Linux (or BSD) servers to direct traffic to the back-end systems if possible. I have seen mention of implementations based off of the Linux Router Project or the global load balancing oriented Eddie. What approaches are other geeks out there using for their LAN load balancing needs? I am especially interested in implementations that can maintain state (ie, handle sessions) as well as do some form of request inspection (so as to redirect those pesky web spiders to their own playground so a live user has the best web experience)." It's been long enough since the last time this came up, so lets revisit this question and touch upon the new solutions that have come up since 1999.

Comments

Re:The problem here is....

[ajvtoo]

One of the projects I'm involved in is the JANET Web Cache Service which is a top level proxy service for the UK academic community.

We use LVS code to load balance our squid boxen at layer 4, and have successfully shifted some 120Mbps through one of our nodes using direct routing on the backends, rather than NATing the system - this configuration barely loaded the frontend (which was only a 500MHz machine) and load balanced some 15-16 backend machines.

ISTR there is some early layer 5-7 code on the LVS site somewhere, but I've not used it, so I don't know how stable it is, or what the performance is like.