Achieving metric oriented load balancing

The Load Balance Service at CERN handles more than 500 aliases, distributed over more than 2000 nodes. After being in production for more than fifteen years, it has been going through a major redesign over the last two years. Last year, the server part was reimplemented in the Go Programming Language, taking advantage of its concurrency features to improve the scaling of the system. This year, the client side has been the main focus. This article describes the client side and its configuration, including the tools used at CERN. All the components used by the Load Balance Service are open source, and they can be deployed at other places.