General Restarting of Services

carliebentley · Tue Oct 10, 2006 12:09 pm

The MySQL upgrade seems to be working well. Thanks a bundle.

However I'm curious about the possibility of restarting mysql in a chron job.

Apache is set to restart gracefully every 15 minutes, however Mysql doesn't seem to be restarting on any routine basis.

I don't think it needs to be restarted every 15 minutes, but maybe once every 2 hours. With all the other services running my server is eating up 90% of the RAM after running for about an hour. I would really like to get that % down to 50%-60%.

I'm going through now and checking for services that are started that my server should never need, like Cups. It's a 1U rack server, it's not like there will ever be a printer connected to it.

RHEL3 updated with Plesk 8.0.1 updated, and now with a fancy new MySQL 4.1.

Any suggestions appreciated.

xian · Unread post by **xian** » Tue Oct 10, 2006 2:22 pm

I dont think you should be restarting MySQL often at all. You might want to run a mysqladmin -u -p refresh every once in a while, but leaving MySQL running will ensure that your cache is full and you are operating at a production level.

I would suggest monitoring your slow query log, or dedicating a specific amount of ram to specific parts of MySQL - search google for optimizing my.cnf - there is a world to know about getting your server running optimally.

My server uses 95% of my ram at all times - (someone correct me if Im wrong) but linux takes all ram into use at all times instead of when it "needs" it. You can start to worry about not having enough ram when you are using a lot of swap.

Check out munin for server monitoring. It's pretty handy.

kwebdesign · Unread post by **kwebdesign** » Tue Oct 10, 2006 5:47 pm

I don't think that 90% RAM utilization is unusual for a Linux box. Like xian said, Linux tends to use as much RAM as is available even if it's not all needed at a given moment.

When I check my server with top, I usually see 90% to 95% used, but if I look at the statistics generated by Plesk's Watchdog module, it never shows above 25% memory usage. I guess the monitoring tool in Watchdog is able to distinguish between RAM that's really in use vs. RAM that's just "got something in it".

Unread post by **scott** » Tue Oct 10, 2006 10:49 pm

exactly, cached ram is better than free ram. Cached means its free, but the app is cached. If something else needs the space it will be loaded, otherwise the cached space will be reused again. In terms of a performance improvement its about x1000000 faster than loading a new app off the disk.