NewsForge has an interesting report on a small, but highly effective way to improve Apache performance. “Lingerd is a daemon process that sits in front of your Apache processes to handle socket IO. What it does is free up your webserver to handle your application layer instead of dealing with clients that tie up your Apache children. This is a huge gain for sites using PHP, mod_perl or one of the Java engines. Having expensive Apache processes waiting around for clients to close sockets is a waste of resources.”
“When the software was installed on Slashdot.org servers, the immediate result was that all of the front end servers that had 40 Apache children running dropped to two. On SourceForge.net lingerd not only dropped child process from around 100 to 10, but decreased database usage because there were fewer Apache processes talking to the database.”