We have a school moodle server (1.61) that is beginning to attract more use, but is suddenly slowing down. It is being run on a P1.8 with 2G of RAM. Win 2K3, etc
I would appreciate suggestions on speeding it up. Are there features which cause the database to slow down significantly? User numbers? (we have 1400)
Note that on a Windows based system a large chunk of your system resources are being used to display a GUI that is very rarely used. If you switch to a Unix based system you get back a huge chunk of resources for doing what the machine is supposed to be doing, serving up moodle.
If you don't have any previous Unix like experience it may seem a steep learning curve, but you can be confident it will be useful in the future.
Also what database engine are you using, i.e. innodb or MyIsam (both MySQL options), I have a suspicion that MyIsam may be faster than innodb. Innodb offers some additional features over MyIsam but they are not used by Moodle.
Thanks. I will work on getting some of these taken care of. Is Linux adequate as an OS?
Is there anything that should be done to speed up the database access. Does having old users around matter? Can I just delete users from the user table in MySQL?
I have seen a couple of messages in moodle.org that mention a possible use of squid as an httpd accelerator. I wonder how much can a squid installation improve performance and what are the trade-offs. I certainly understand that the benefit can vary depending on the installation; yet I hope that there are some generic guidelines/estimates that one can look at before trying squid. Any hints would be appreciated.
Some words about squid (in poor english...):
A PHP-cache caches php-outputs, but only identical php-outputs. The hitrate of php-caches with moodle should not be to high because any site is delivered individually for each user. You will experience a great performance boost with sites with many simultaneous users using a PHP cache anyway, because of the simple mass of requests. If only 20% could taken from cache you'll save much resources.
Squid can be configured to run in reverse-proxy mode. Squid caches an kind of content (e.g. pictures, soundfiles etc.). Your webserver then works not web-accessible e.g. on port 81. Squid delivers the content on port 80 asking your webserver only when objects are not in his cache. Same PHP-outputs should be taken from squid cache, too, but squid can cache a bigger variety if data.
I found no big difference between reverse-proxy or a php-cache.
I have got a small machine. We are running 60 Clients simultaneously with a Duron 1200 and 512Megs of RAM. Performance is even fine with the test module.
I am currently using lighttpd as webserver and PHP runs in fastCGI mode with individual user permissions for each moodle installation. If I run in trouble some day, I would try out a additional reverse proxy before moving to another machine.
lighttpd is worth a look for many reasons. My PHP-threads could even run on another machine and loadbalancing is integrated. So my installation is able to scale very well. lighttpd consumes not much RAM either.
regards,
Maik
