Hi, The solution for this problem is to decrease the wait_timeout variable to something more reasonable than 28800 seconds. If you have a very loaded server, I thing a wait_timeout of 60s is great (in my case). However I hardly understand why in some cases mysql seems to be no able to reused IDLE connexion (which entails the well known problem of two many connexion).
Regards, Jocelyn ----- Original Message ----- From: "Paul DuBois" <[EMAIL PROTECTED]> To: "Tod Harter" <[EMAIL PROTECTED]>; "Thomas Seifert" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Wednesday, August 14, 2002 7:25 PM Subject: Re: Persisten Connections > At 11:14 -0400 8/14/02, Tod Harter wrote: > >On Wednesday 14 August 2002 09:54 am, Thomas Seifert wrote: > > > >I disagree entirely.... > > > >Persistent connections have little or nothing to do with increasing load! > > > >Given that you mention you are using PHP I'll assume you have mod_php running > >in Apache. Each Apache child process in this configuration will maintain ONE > >open database handle, so 100k pageviews per day I would expect you might max > >at like 30k in one hour, or around 10/second, so you might top out at roughly > >100 Apache child processes at any one time, thus 100 database connections. > > > >Each DB connection is not a huge overhead, but creating and destroying 10 > >database handles PER SECOND is a large overhead!!! Remember, every time mysql > >creates a connection it has to do internal queries on the grant tables. I > >don't know exactly what the overhead of that is going to be, but ANYTHING > >that creates 10 queries per second is putting some strain on your database > >server! > > > >One of the main goals of using Apache modules for scripting was to allow > >persistent database connections. There is really NO reason to give up that > >advantage. Remember, MySQL is multi-threaded, with one thread per connection, > >so the resources for a database connection are on the order of under 100k of > >memory per connection. > > There is at least one reason, which is that persistent connections cause > the server to hold open connection slots even the connection isn't actively > being used at the moment. This can cause the MySQL server to run out of > connection slots and result in connections being refused. Using non-persistent > connections under such circumstances can be beneficial because on average, > the server need hold fewer connections open. > > This has been found to solve connection-refused issues in a number of > cases on this list. > > --------------------------------------------------------------------- > Before posting, please check: > http://www.mysql.com/manual.php (the manual) > http://lists.mysql.com/ (the list archive) > > To request this thread, e-mail <[EMAIL PROTECTED]> > To unsubscribe, e-mail <[EMAIL PROTECTED]> > Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php > > > > --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
