MySQL error: max_user_connections

[carverrn]

We've been running SupportSuite for months without any significant problems. Today we encountered the following error:

Warning: mysql_connect() [function.mysql-connect]: User runcom_kayako5 has already more than 'max_user_connections' active connections in /home/runcom/public_html/support/includes/functions.php on line 421
User runcom_kayako5 has already more than 'max_user_connections' active connections

Our server tech support said that he noticed that most of the MySQL processes were sleeping and suggested that the application, SupportSuite, may not be properly closing it's database connections all the time.

Is this a known issue?

Regards,
Rich

[John Haugeland]

This indicates that you're hitting the RAM limit on your hosting, and that your host has not appropriately configured MySQL to clean up zombie connections (something PHP cannot do by definition). MySQL is configured by default to allow those connections to sit around for eight hours, because it expects to be used in datacenters.

Please advise your host to update their MySQL configuration to a more sensible max connection time. Having MySQL connections sit around that long on web hosting is not useful; very few web hosts allow applications to run in unbounded time in the first place, so the chances that a connection even can be useful past the five or so minute mark is exceedingly low.

They're looking for the mysql setting "wait_timeout", which is in my.cnf; if they don't know how to update server variables from the console, they'll also need to restart their database server.

[carverrn]

Our host said there was a lot of connection threads that were sleeping. According to phpMyAdmin "Server variables and settings"our "wait_timeout" value is set to 20.

We recently had some server updates too (apache, PHP4, PHP5) but the MySQL server (4.1.22-standard) was not updated.

Any ideas or suggestions?

Thanks,
Rich

[Jamie Edwards]

Hi Rich,

What is max_user_connections set to?

[carverrn]

I'm not sure what max_user_connections was but here is was our server support said today:

Your software seems to be keeping persistent connections and it accumulates causing this issue

+--------+----------------+-----------+---------------+---------+------+-------+------------------+
| Id     | User           | Host      | db            | Command | Time | State | Info             |
+--------+----------------+-----------+---------------+---------+------+-------+------------------+
| 183318 | runcom_kayako5 | localhost | runcom_kaYako | Sleep   | 8866 |       |                  |
| 183533 | runcom_kayako5 | localhost | runcom_kaYako | Sleep   | 8446 |       |                  |
| 183553 | runcom_kayako5 | localhost | runcom_kaYako | Sleep   | 8400 |       |                  |
| 183571 | runcom_kayako5 | localhost | runcom_kaYako | Sleep   | 8353 |       |                  |
+--------+----------------+-----------+---------------+---------+------+-------+------------------+

Anyhow I have increased the max user connections to 80 now.

We are, and have been from the start, running the mail parser from a CRON job "http://support.ourdomain.com/cron/index.php?_t=parser". Could that be leaving any connections open? We were running it every 5 minutes but I've changed it to every 10 minutes for now.

Regards,
Rich