CNET News: Piranha or Monkey? Open source clustering with LVSApr 29, 2001, 12:00 (2 Talkback[s])
(Other stories by Todd Underwood)
"With so many commercial Linux clustering products on the market, administrators may be surprised to learn that high-quality, open source clustering solutions can provide functionality similar to that of commercial clustering products at little or no cost. Projects such as Red Hat's Piranha (from the High Availability Server Project) and Ultra Monkey use the Linux Virtual Server Project's Linux Virtual Server (LVS) technology to provide complete balancing of services among a group of servers according to a variety of scheduling algorithms. Composed of several components, LVS supports most of the features provided by commercial packages such as PolyServe LocalCluster Enterprise and Turbolinux Cluster Server, although it does require more technical know-how to achieve the same results."
"LVS's core kernel code, ipvs, routes service requests from clients to the servers that provide the services. It also keeps track of the requests and the connections associated with them to ensure that they're delivered to the appropriate servers. Used in tandem with monitoring software, ipvs provides failover services for servers that are down as well as distributed management and load balancing."
"LVS uses several load-balancing algorithms, including round robin, least connections, weighted round robin, and weighted least-connections. LVS also supports a variety of different network architectures. The system's main disadvantage is that it's significantly more difficult to install and configure than most commercial offerings such as Piranha and Ultra Monkey, both of which offer easier installation and configuration."