About This Site
Server Load Balancing
SLB (Server Load Balancing) started out in the mid-90's as a method to provide high availability, flexibility, and scalability to web sites which were becoming more and more critical.SLB addressed several problems facing Internet sites dealing with an ever increasing traffic load in a simple, platform independent, protocol independent, and elegant way. One of the problems was scaling a site to handle more traffic. Most modern operating systems don't scale web functions well beyond 4 processors, and even if they did, a 10-processor machine costs way more than 10 1-processor machines, and scales better. A load balancer allows a site to use 10 1-processor machines while still using a single IP address to route DNS to.
Another problem was handling failures of equipment. Load balancers routinely check for the availability of all the machines it distributes traffic to, and if one machine goes down, it will automatically stop sending traffic without the need for manual intervention.
SLB is extremely pervasive and load balancers are installed in virtually every medium to high-trafficked running on the Internet today. There are a number of vendors are manufacturing load balancers, including Cisco, Foundry, and Nortel, just to name a few.
While load balancers are extremely pervasive, they aren't understood very well. Thus there existed a need for third party non-vendor resources that related to the various aspects of the technology.
Today's vendors do a great job of providing resources, but a user community and their solutions for various problems can be invaluable. So I put together a number of tools and resources that are vendor-neutral, and either freely accessible (such as this site) or readily accessible (such as the O'Reilly book) to help people learn to use and to better manage server load balancers.
The load balancing mailing list was setup in July of 2000 as a place to discuss problems, concepts, and configuration of sever load balancers and related issues. It started with only a handful of subscribers, and now boasts over 800 users. If you have a question or problem related to server load balancing, chances are someone on the list will have an solution or at least a nudge in the right direction.The lb-l List Archive
There is a searchable archive to the mailing list. You can use the search form below:MRTG and SLB
MRTG is a powerful tool to collect, trend, and graph various performance metrics. By default, MRTG will allow you to measure the bandwidth for every network interface on a load balancer. With the right OIDs from the vendor, you can trend even more, such as connections per second, bandwidth per VIP, and much more.Server Load Balancing
Published by O'Reilly in August of 2001, the book Server Load Balancing was written by Tony Bourke and is a guide to the general configuration and installation of load balancers into a given infrastructure. The book can be purchased from most online and retail book sellers.
About Tony Bourke
Tony Bourke is a a prolific technical writer on various subjects such as
Unix and Unix-like systems, networking, and load balancing. He lives and
works, and generally lives the Sexy Unix Lifestyle in New York City.
He enjoys eating vegan food, running, and drawing in his spare time, and
can be reached at tony (at) vegan dot net.
About Vegan
Veganism is a strict form of vegetarianism. Vegans do not eat meat, including chicken and fish, and also do not eat dairy products such as milk or eggs. Vegans do not generally wear leather or wool, or use, wear, or eat any products that are derived from animals. Load balancers are not derived from animals. Tony Bourke has been vegan for 8 years.The SLB sites sit on vegan.net for no other reason than it's the domain Tony owns. Tony is no way wants to push his vegan lifestyle upon others (rather than promoting an idea, belligerent preaching more often turns people off to an idea), and vegansim generally won't come up unless you bring it up, or decide to go out to eat with him. Being vegan, eating out with Tony can sometimes be a pain in the ass.