http://queue.acm.org/detail.cfm?id=3028689 Everything Sysadmin: Are You Load Balancing Wrong? Anyone can use a load balancer. Using them properly is much more difficult. Thomas A. Limoncelli A reader contacted me recently to ask if it is better to use a load balancer to add capacity or to make a service more resilient to failure. The answer is: both are appropriate uses of a load balancer. The problem, however, is that most people who use load balancers are doing it wrong. In today's web-centric, service-centric environments the use of load balancers is widespread. I assert, however, that most of the time they are used incorrectly. To understand the problem, we first need to discuss a little about load balancers in general. Then we can look at the problem and solutions. A load balancer receives requests and distributes them to two or more machines. These machines are called replicas, as they provide the same service. For the sake of simplicity, assume the