Hi John --
> But meanwhile, we're still open to alternatives. > Surprisingly, there don't seem to be many (software) options. > (A hardware load balancer is not an option at his time, but > I'll also take any suggestions in that area :) Why is hardware not an option? Cost? If so, I'd take a look at the system Nick recommended -- the Coyote Point Equalizer: http://www.coyotepoint.com/equalizer.htm A few years ago I bought their "E-250". It cost about $3,200, which was nothing compared to the other solutions out there at the time. This load balancing system (LBS) was for a corporate intranet with a user base of 50k to 60k users, with the expectation that it would be capable of handling a third of the total user base at any time. The CPE-250 handled the job with ease. We initially rolled out with four separate "Web Application Server" machines ("LAMP" architecture), and a procedure to allow us to add additional machines in four hours, if need be. The system has been in production for about two years. In that time we have had individual servers crash, but the intranet has had less than 15 minutes of downtime since we implemented the CPE. Regarding software solutions, mod_perl or otherwise: I initially looked at this, and ultimately rejected it as an option. No robust systems had emerged at the time. Based on a cost/performance comparison against the CP product I calculated it would cost far more than $3,200 to roll our own system which would provide the configurability, ease of use and reliability of the available hardware solution. FWIW, the "Equalizer" is implemented as a rack-mountable BSD machine running custom software. The software implements load-balancing via dynamic port-forwarding (*NOT* an HTTP proxy), so it is capable of forwarding any TCP service (SMTP, database, etc.). The GUI is web-based, very easy to use, and includes graphical reporting of activity. Load balancing can be configured to be purely round-robin, but the CPE features a very effective dynamic adaptive load balancing system based on server response time which is very effective. It has been a couple years since I talked to Coyote Point about their product. I would check to see if it is still cost-competitive. HTH, -Jesse- -- Jesse Erlbaum The Erlbaum Group [EMAIL PROTECTED] Phone: 212-684-6161 Fax: 212-684-6226
