This chapter describes how to tune your operating system. Proper OS tuning improves system performance by preventing the occurrence of error conditions. Operating system error conditions always degrade performance. Typically most error conditions are TCP tuning parameter related and are caused by the operating system's failure to release old sockets from a close_wait call. Common errors are "connection refused", "too many open files" on the server-side, and "address in use: connect" on the client-side.
In most cases, these errors can be prevented by adjusting the TCP wait_time value and the TCP queue size. Although users often find the need to make adjustments when using tunnelling, OS tuning may be necessary for any protocol under sufficiently heavy loads.
Tune your operating system according to your operating system documentation. For Windows platforms, the default settings are usually sufficient. However, the Solaris and Linux platforms usually need to be tuned appropriately.