Pen is a load balancer for "simple" TCP-based protocols such as HTTP or SMTP. It allows several servers to appear as one to the outside. It automatically detects servers that are down and distributes clients among the available server for high availability and scalable performance. The load balancing algorithm tracks clients and tries to send them back to the server they visited the last time. The client table has slots (default 2048, settable through command-line arguments). When the table is full, the least recently used one is discarded to make room for the new one. This is superior to a simple round-robin algorithm, which sends a client that connects repeatedly to different servers. This breaks applications including most modern web applications) that maintain state between server connections.
DocumentationUser tutorial available from http://siag.nu/pen/howto.shtml
released on 6 July 2004
|License||Verified by||Verified on||Notes|
|GPLv2orlater||Janet Casey||15 January 2002|
Leaders and contributors
Resources and communication
This entry (in part or in whole) was last reviewed on 23 January 2009.