If you are running MySQL on Windows, then I'm wondering
whether you are having a problem with running out of
available ports, for clients to connect to MySQL on.
This may be your problem:
From the manual, 2.3.16. MySQL on Windows Compared to MySQL
MySQL for Windows has proven itself to be very stable. The
Windows version of MySQL has the same features as the
corresponding Unix version, with the following exceptions:
Limited number of ports
Windows systems have about 4,000 ports available for client
connections, and after a connection on a port closes, it
takes two to four minutes before the port can be reused. In
situations where clients connect to and disconnect from the
server at a high rate, it is possible for all available
ports to be used up before closed ports become available
again. If this happens, the MySQL server appears to be
unresponsive even though it is running. Note that ports may
be used by other applications running on the machine as
well, in which case the number of ports available to MySQL
For more information, see
In theory, theory and practice are the same;
In practice they are not.
On Sun, 12 Feb 2006, Aaron Axelsen wrote:
> To: mysql@stripped
> From: Aaron Axelsen <lists@stripped>
> Subject: Weird MySQL Connection Issues
> I have been experiencing some weird MySQL connection issues lately.
> Twice now in that last couple weeks, there have been times where some
> mysql applications are working, and others are not working. Both times
> the mysql connection limit was rather high. A simple mysql restart has
> fixed the problem both times.
> There are a few forums using phpbb running on this server which get
> heavy access, which is most likely the cause of the problem.
> The version of mysql running is: 4.1.14
> Is there a known issue like this with alot of mysql connections?
> Does anyone have any related ideas or suggestions? Thanks!
> Aaron Axelsen