Andrea Benedetto wrote:
> We have a big mail server which authenticate users against mysql
> (mysql server 4.1.10 and mysql client 4.1.10).
> Some times we can see in /var/log/qmail/smtpd/current this line:
> 2005-04-04 11:43:50.962470500 vmysql: sql error: MySQL server has
> gone away
> and after this qmail-server says that the mail box doesn't exists.
> We have read that it could be a timeout error, because vpopmail keep
> alive conections with mysql server but mysql doesn't (wait_timeout =
> 28800). But probably this isn't the case, because in the log file we
> can see that the error above doesn't occur every 8 hours but it
> appears at every time.
> Here an example:
> 2005-04-04 01:30:47.096746500 vmysql: sql error: MySQL server has
> gone away 2005-04-04 08:25:35.172402500 vmysql: sql error: MySQL
> server has gone away 2005-04-04 08:25:38.270531500 vmysql: sql
> error: MySQL server has gone away 2005-04-04 11:45:26.640551500
> vmysql: sql error: MySQL server has gone away 2005-04-04
> 17:24:29.706105500 vmysql: sql error: MySQL server has gone away
> 2005-04-04 19:30:11.903721500 vmysql: sql error: MySQL server has
> gone away In other days we haven't any errors.
> Can you help us?
Is it possible that you're hitting your MySql max connections? The default
is 100 simultaneous connections.
Try running this...
mysql -uroot -p<mysql password> -e 'show status;'|grep Max_used_connections
If you haven't restarted MySql since the problem was last seen...and if it
shows 100...then that is your problem.
As a side note, I reported the fact that maxing out connections bounced mail
to the devs some time ago. I think they've fixed that in more recent