From: Michael Widenius Date: April 17 1999 8:10am Subject: Disconnections Part 2 List-Archive: http://lists.mysql.com/mysql/1980 Message-Id: <14103.3149.390905.929638@monty.pp.sci.fi> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hi! >>>>> "Vinny" == Vinny Stoessel writes: Vinny> Hello, Vinny> I posted a couple of days ago how I was noticing Vinny> brief moments of "Cannot connect to Mysql" errors Vinny> from my local apache server that connects via sockets Vinny> in Linux 2.0.35 and a remote one that connects via Vinny> TCP. I have set max_connections to 600. The web servers Vinny> are each limited to 200 children so I should never have Vinny> to worry about ever reaching the 600 mysql connection Vinny> limit. yet I still get occasional connection refusals. Vinny> Now I did see something in the error log: Vinny> 990415 15:01:57 Error in accept: Invalid argument Vinny> 990415 15:12:00 Error in accept: Invalid argument Vinny> 990415 15:22:25 Error in accept: Invalid argument Vinny> any one know what this is telling me? Vinny> I enabled logging and grepping out "Connect" I get Vinny> 990415 15:31:22 1 Connect client@localhost on hitlist Vinny> 2 Connect client@localhost on Vinny> 990415 15:31:25 3 Connect client@stripped on Vinny> 990415 15:31:34 4 Connect client@localhost on adserver Vinny> 5 Connect client@localhost on Vinny> 990415 15:31:43 6 Connect client@stripped on Vinny> 990415 15:31:44 7 Connect client@localhost on Vinny> 990415 15:31:48 8 Connect client@localhost on xaymaca Vinny> 9 Connect client@localhost on Vinny> 10 Connect client@localhost on Vinny> should the Connect argument after "user@host on" be blank Vinny> like some these lines are showing? The empty 'on' part means that client didn't specify a database name when connecting. I assume you have set up your Linux system with enough file descriptors? Vinny> I am running mysql 3.22.21 Linux (Binaries) on a Vinny> 233 Pentium with 192M of Ram. apache and a realaudio server Vinny> also run on this box. Any insight is appreciated. Vinny> Thanks. I am aware of a kernel bug in Linux 2.2 that if one does very rapidly TCP/IP connections then after a while one will get failed connections. This appears to be some inner resource in Linux that is not freed at once, but freed eventually as this problems disappears after a while. (I haven't noticed this problem with a 2.0 kernel, but...) Do you only get refused connections on the remote machine or also on the local one? Regards, Monty PS: If anyone is interested in a full TCP/IP test that shows this problem I have one available. I have posted this a couple of times to Linux developers but never got any responses.