Calculating the Needed Size and Speed of a Server

Calculating the Needed Size and Speed of a Server

Don Hinkelman發表於
Number of replies: 9
Particularly helpful Moodlers的相片 Plugin developers的相片
How do you calculate the size and speed of your server if you host Moodle yourself?  This is an important question raised in another topic by Martyn Overy.  He adds...

I cannot see, however, how you can state that using Moodle was not the cause of the server problems, since the whole exercise seems to be based on the running Moodle, with your server. It would appear that the configuration of the server could not meet the demands of Moodle. It has become more than clear to me that Moodle can have excessive demands  servers, and hosting companies are already starting to chuck users off as a result of  Moodles 'eating servers for breakfast'

Thank you Martyn, for pointing out problems of carefully choosing and configuring a server to match your needs.  I think you would agree that a large university would need a larger server and more servers than a small school.  In my case, I took a small single server (933mhz, 768MB ram) to the limit.  A systems supervisor would laugh at my naivete.  That is the beauty of Moodle though.  Any teacher can try it and set it up and try things that an IT department would never attempt.  As I mentioned, please contact University of York or University of Glasgow to hear about their user needs and how they have set up their Moodle servers.

"Simultaneous" users is a peculiar problem if you are running large laboratories and are giving an introduction to freshmen who have no idea what to do.  In that case, you instruct them step-by-step and they ALL hit the same button at the same time.  In my experience, that load is equivalent to a 20,000 user school where 1000 users are online and all doing different tasks.

Are hosting companies chucking off users for using Moodle?  On the contrary, many hosting companies are aggressively courting Moodle users.  Netmondo.com recently offered a discount to Moodle users (they currently cost US$29 per year for a site with Moodle installed running unlimited MySQL databases, 500MB space)  I have seen providers with rules that forbid running any chat programs on their servers.  Those kind of providers cater to people with static web sites, and of course a Moodle user or any eLearning site user, or interactive site creator would not qualify.

How about the competitors?   Do WebCT and Blackboard make more or less demands on servers than Moodle?   I would be curious to hear if any one has experience in this area. 

And how do you calculate hardware needs for a school?  Martyn reports his school has 1600 users.   I would guess to calculate the size of server you would need to include the number of courses, the number of times a student would access per week, the types of activities (chat is usually the most demanding), the internal transfer rates on campus and other  important points.  smile




評比平均分數: -
In reply to Don Hinkelman

Re: Calculating the Needed Size and Speed of a Server

Martin Dougiamas發表於
Core developers的相片 Documentation writers的相片 Moodle HQ的相片 Particularly helpful Moodlers的相片 Plugin developers的相片 Testers的相片
I really don't mean to sound trite, but the best answer I think is the "the biggest server you can afford". Moodle is always changing, as is PHP, Apache and MySQL. The system administrator's experience is always changing, and of course the usage (and patterns of usage) by students will also always be changing. There are just too many software and human factors to "calculate" anything.

By comparison, hardware for running Linux is very cheap and reliable, so go for overkill and get as much as you can.  Your server may be trickling along at 10% usage most of the time (like mine do) but occasionally you will be glad you had the excess power to handle something unexpected (eg full backup at the same time as a big class doing big quizzes plus maybe a virus attack from the internet).
評比平均分數:Useful (1)
In reply to Martin Dougiamas

Re: Calculating the Needed Size and Speed of a Server

Tony Patton發表於
Martin,

I have recently installed Moodle and hope to move the school to this product from the existing leraning platform. However, when multiple students attempt to access the main page simultaenously we are encountering multiple speed issues and often times out. It is using the same server and mySQL database that we use for our existing system. Any ideas?
In reply to Tony Patton

Re: Calculating the Needed Size and Speed of a Server

mandy honeyman發表於
Hi tony,

One of the things that I found was to change the dppersist setting in config.php. Doing that allowed a class of 30 to log onto moodle at exactly the same time without issue.

Sorry can't find the original posting about this.

cheers
Mandy
In reply to mandy honeyman

Re: Calculating the Needed Size and Speed of a Server

Bhupinder Singh發表於

What did you change the setting to (was it true). What was the improvement after the change.

Thanks in advance

In reply to mandy honeyman

Re: Calculating the Needed Size and Speed of a Server

Dan McMahon發表於

http://moodle.org/mod/forum/discuss.php?d=21279

I think that's the thread you want - discusses the dppersist setting and a couple of related tricks.

EDIT: It was dbpersist, not dppersist, maybe that's why the post was hard to find!smile

Dan

In reply to Dan McMahon

Re: Calculating the Needed Size and Speed of a Server

Genner Cerna發表於
40 students log the same time hang or server dies even dbpersist is off
In reply to Genner Cerna

Re: Calculating the Needed Size and Speed of a Server

Genner Cerna發表於
php comsume most of the cpu.... thus hangs the server...
In reply to Genner Cerna

Re: Calculating the Needed Size and Speed of a Server

Arnor Kristjansson發表於
I'm having the same issue with ~60 students using the site at the same time. When you add chat (regular, not daemon...the daemon doesn't play well on a vserver) to the mix I can effectively kiss the whole system goodbye. The system is a Xeon 3,2GHz 1Gig of RAM running Debian linux.

I think I saw some post somewhere that moodle had tuck-mmcache (or something comparable) built-in. Is this true?
In reply to Arnor Kristjansson

Re: Calculating the Needed Size and Speed of a Server

Gavin McCullagh發表於
Hi,

turck-mmcache is packaged for Debian and I'm using it here for Moodle without any noted issues. You have to be using PHP4 not PHP5 though. There is a forked version for PHP5 but it's still in development and not yet in Debian stable (or even testing?) as far as I know.

http://eaccelerator.net/HomeUk

Gavin
評比平均分數:Useful (1)