Joomla! Discussion Forums

Hello,

I look after a popular site that's been churning/timing out for several months now. This has been roughly traffic-related (ie. often during its busiest period) but also sometimes happens at seemingly random times of day and night. We have tried everything we can think of - Joomla/MySQL caching, increasing/decreasing MaxClients, reducing page size, as much logging and monitoring as we can think of for starters. Everything else but Joomla is extremely quick on the server, which is pretty high-spec and dedicated to this site only.

The site's losing traffic and ad revenue so we need to get it sorted. If you consider yourself to be a specialist in diagnosing and resolving Joomla-specific unix server problems, please get in touch.

Thanks

My first suggestion would to turn on the MySQL slow query log if it is not already on:
http://dev.mysql.com/doc/refman/5.1/en/slow-query-log.html

Then wait for the next time the site is unresponsive and see if anything pops up in that log.


How often does this happen?

Do you have any type of cron job setup to tell you when it is happening? I just have a simple script that calls a page on my site every minute and lets me know if the server doesn't respond. I think cPanel/Plesk may have a way to configure something similar.


Let me know if you find anything and need help figuring out what is causing it. If you happen to find a slow running query, it may be difficult to tell which component is causing it.


Upgrading to 1.5 probably wouldn't hurt either

Thanks for the response. We'll set slow query logging up today. We'll also be upgrading to 1.5 later this month - and changing server as a last resort. The site's been transferred twice so there's a suggestion that settings for a previous server aren't optimal for the current one.

We don't have a specific notification script but the site is monitored very closely both via logging and by everyone who works on it. We have a MaxClients script that restarts whenever that hits 150 (a number we've varied) and logs the clients number every minute.

The timing is strange - sometimes nothing for over a week, then several times in several consecutive days like this week. What would be really useful is to see exactly what resources are being used and by whom when it does slow down - to see if it's a specific page/IP/modules/banner ad that's triggering it.

Traffic-wise, the site gets a steady 300,000 unique visitors a month and 3.5 million page impressions. At its busiest, it has 1,800 people on it at any one time, and 50,000 for that day. But the slow downs happen when there's as few as 800 people on there.

Any additional thoughts/suggestions?

Logging is your best bet. Like you were saying, if you want to get stats on the server when things are slow, I would just setup a script to log anything you find interesting and have it run every minute. I had something that would run and dump the output from top and the output from mysqladmin show processlist. You could also hit some of your MySQL tables to get stats, but make sure to keep your connect timeout low since MySQL may not be responding when the server does slow down.

Let us know what you find.

So - touching wood - it seems that this is resolved. We transferred over to a temporary server and wiped the main server, reinstalled Apache, and transferred it back. Bad installation perhaps.

A scary yet simple resolution. It's possible something was wrong and that would fix it. If it becomes an issue again, just let us know.