Date: Sat, 19 Jul 2003 05:30:49 -0700 (PDT) From: Van Vinh Vo <vovanvinh2001@yahoo.com> To: freebsd-net@freebsd.org Subject: accept filters Message-ID: <20030719123049.82835.qmail@web21008.mail.yahoo.com>
next in thread | raw e-mail | index | archive | help
Hello all, I read the notation of accept filter from google, but i don't well understand, this text as following "Versions of FreeBSD from August 2000 onwards include a feature called "accept filters" which delay the return from accept() until a condition has been met, e.g. an HTTP request has arrived. This postpones the requirement for a child process to handle the new connection which therefore increases the number of connections that a given number of child processes can handle. It also allows a child process to accomplish more immediately after accept() returns (because the request is already available to be read) so there is less context switching. Accept filters provide the most benefit on servers that are already so busy that they are configured with "KeepAlive Off". HTTP KeepAlive (aka persistent connections) avoids the cost of setting up a new connection for every request, but connections that are being kept alive use up one of the available child processes. Since there is a limited number of child processes this can significantly reduce the capacity of the server. The viewers of a web site will still get a lot of the benefit of persistent connections even with a very small KeepAliveTimeout so you should try reducing it before turning it off altogether." from http://httpd.apache.org/docs/misc/perf-bsd44.html "accept filter delays the return from accept() until a condition has been met " does it mean that it delays the connection of sockct when the system is processing others instructions ? "it allows a process to accomplish more immediately after accept() returns ! what does it mean ? " does it mean that when a process is rruning, the system receive a connexion, it delay this connexion and continue running this process, after that it accept the connexion ! and how can we configure this accept filters ? please explain me Thanks for your helping Vinh __________________________________ Do you Yahoo!? SBC Yahoo! DSL - Now only $29.95 per month! http://sbc.yahoo.com
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030719123049.82835.qmail>