Performance FAQ

How do you define "concurrent users"?

As has been repeatedly stressed in the Hardware and performance forum, the load on the server at a particular time depends on the number of concurrent users, not on the total number of users neither on the number of users logged-in. The term "concurrent users" is used to mean those users for whom the server is actively doing something . It may by processing a webpage written in PHP, querying the database or simply transferring a file. (see also Wikipedia Concurrency)

How do I benchmark a Moodle-site?

You can of course benchmark parts of the system separately: hardware as seen by the operating system (eg. disk access speed), web server performance, database server performance, execution of PHP, etc. For further information see Performance#Obtain_a_baseline_benchmark.

But there is no easy formula to deduct the maximum number of concurrent users from those results. There is a PHP-script, the Performance perspectives - a little script, circulating amoung the Moodle-community which calculates a ballpark figure. The current version is attached to the posting on 1. March 2007.

Warning: Note that running this script on a production server may have unwanted side-effects. You are strongly adviced to run it on a test-site.

What are PHP-accelerators?

See Wikipedia PHP accelerator.

Available software are documented under Performance#PHP_performance.

You find some user suggestions here Update on PHP-accelerators.

How do I cluster Moodle?

See Performance#Scalability

Moodle_Clusters

How do I replicate Moodle?

Mirroring_Moodle

How to Replicate MOODLE ??!!

My site is very slow, what should I do?

First find out "how slow". (The theme-trick here).

The next question is, whether the performance is normal or something malfunctions. There are many things which can malfunction:

• hardware
• crashed filesystems, specially network filesystems
• memory leaks or other crashes in the system
• bug in Moodle
• corrupted database
• networking issues (DNS, firewalls, ...)

Or your performance could be "normal" under the given circumstances:

• Are you on a dedicated server or a shared (virtual) server?
• How much RAM, processing power do you have?
• What is the software stack you use? (Unix or Windows, Apache or IIS, MySQL, PostgreSQL or SQL-Server, ...?)
• how many concurrent users can you support
• what modules/activities you use? Check Performance#Performance of different Moodle modules

Performance#Obtain a baseline benchmark and compare it with the published figures.

What are the requirements for N users?

A moodle setup for 10K simultaneous users

How many users will my installation support?

This is another way of asking the same question as above. Please move up.

Which operating system is the best?

Beginning_Administration_1_FAQ#Installation_on_a_Windows_or_a_Linux_server

What hosting provider do you recommend?

http://moodle.org/mod/forum/discuss.php?d=99405

See also

Moodle Docs

• Performance
• Category:Performance

Forum discussions

• All performance related discussions
• Performance related discussions in the General Developer forum

• 1000 concurrent users
• Tool to estimate server's maximum concurrent users
• Handling Moodle database load - a solution!