quiz for 150 students

quiz for 150 students

by ziv izackov -
Number of replies: 9

Hi

relatively new user in this amazing world of moodle, i am a windows sys admin.

i was asked to check the option of running a test for 150 CONCURRENT users using moodle. 

this is the setup:

cpu:  4th Gen Intel® Core™ i7-4800MQ 

ram: 32GB DDR3 1600MHz

hdd: 1x ssd 500GB

os: ubuntu server 16.04 LTS,  moodle version: 3.2.1+ database: mysql (5.7.16-0ubuntu0.16.04.1) php: 7.0.13.0.0.16.04.1

the test will be very big, 500 true/false questions (no videos or sound)

the server will be onsite, on a 1Gbps lan. and i don't need internet connection for the test. 

I have searched the internet for real world examples of big tests using moodle, but did not found anything similiar.

i would appreciate your opinion   and your suggestions to how to poll this off. 

is there a way to simulate the quiz in order to check it's performance before the exam? 

thank you for all your help.  


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In reply to ziv izackov

Re: quiz for 150 students

by Howard Miller -
Picture of Core developers Picture of Documentation writers Picture of Particularly helpful Moodlers Picture of Peer reviewers Picture of Plugin developers

As long as your apache/mysql and so on are properly tuned then I would imagine you are in with a chance. 

However, nobody can really tell you without you trying it as there are so many variables. Also, have you got any kind of monitoring on this server so you can see how it is performing?

Is there any way you can do a pilot to see how it performs? Also, is there any possibility of staggering the start of groups of students by a few minutes to avoid the huge hit on the server when they all press the button at exactly the same time?

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In reply to ziv izackov

Re: quiz for 150 students

by ziv izackov -

thank you both for your inputs. appreciate it.  

unfortunately i can't do a demo/pilot test before the real teat because  it's a one time medical certification exam, and the participants are not part of a class.

I do understand that no one can guarantee that everything will work smoothly, but i want to minimize the risk as much as possible. 

any other suggestions? 

thanks again 

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In reply to ziv izackov

Re: quiz for 150 students

by Howard Miller -
Picture of Core developers Picture of Documentation writers Picture of Particularly helpful Moodlers Picture of Peer reviewers Picture of Plugin developers

Monitor the server (e.g. Munin), get as many volunteers as you can and try it. See what happens. If your server nearly maxes out with 10 people then I would start worrying. 

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In reply to ziv izackov

Re: quiz for 150 students

by Ken Task -
Picture of Particularly helpful Moodlers

In addition to the good advice you've gotten so far .... 2 cents ...

Moodle actually comes with some server testing tools (jmeter) *that should only be run on a non-production server* (due to the nature of the test and what is required to run a test with multiple users who might be doing multiple things in the Moodle).

It would be wise to clone the site and run such testing on the clone.

Since you've mentioned specifics, one comment related to the quiz/test itself ... 500 questions are a lot and assume you will break apart how many questions are displayed to each user at a time which is a setting in the quiz itself.   Obviously 500 at a time per user will stress any server.  How many per page is anyone's guess.

Depending upon how much time you have ... check out the information Digital Ocean has written on JMeter:

https://www.digitalocean.com/community/tutorials/how-to-use-jmeter-to-record-test-scenarios

Truth in sharing ... I've not done the above, but it looks like one might be able to record a single student login to the *cloned server* in jmeter using FireFox - step through a couple of quiz pages, an then be able to use the jmeter plan/script to increase the number of users.

Having said that, am going to provide an educated guess that at least one MySQL setting will need to be increased .... max_connections.   Right out of the shrink wrap, the default is 151.   Think I'd set that higher even without testing.

'spirit of sharing', Ken


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In reply to Ken Task

Re: quiz for 150 students

by Howard Miller -
Picture of Core developers Picture of Documentation writers Picture of Particularly helpful Moodlers Picture of Peer reviewers Picture of Plugin developers

True, but.... http://www.mysqlcalculator.com/

Make sure you are using the memory you have. But not too much wink

Generally speaking (out of the box) MySQL will be very conservatively configured and Apache will burn up all your ram.

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In reply to Howard Miller

Re: quiz for 150 students

by Ken Task -
Picture of Particularly helpful Moodlers

Very true, Howard.   Useful link also!   Hadn't discovered that one!

Have one other thought ... 'networking comes before application' ... I used to provide technical support for/at a week long State wide convention held at a venue for such gathering.  The venue needs to have the infrastructure to handle usage - things like DHCP server, DNS server, etc. have to be able to handle the extra.

The moodle itself has a requirement for FQDN IF using a FQDN or static IP.   So if you've set the Moodle server up with a private IP and used a FQDN that isn't present at the venue, once the Moodle server is on location, one might have to tweak things before it can be used at the venue.

I would imagine the site/location chosen for this test is a medical facility.   That location, I would imagine, would have robust infrastructure and can handle the number of users not normally at that location but assembled just for this test.  Also assume that there is a wireless network present at the venue robust to enough to handle the 'extra' 150 folks.  It wouldn't hurt to check with the IT/Networking people at the physical site.  

And, would also assume, that these medical people will be bring their own device to the venue chosen for the testing site.   Shouldn't be a factor but if they all bring personal tech ... would those be iPhones, iPad's, Android's, etc..?

More 2 cents. ;)

'spirit of sharing', Ken


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In reply to Ken Task

Re: quiz for 150 students

by ziv izackov -

Hi

thank you!

it will be 10 questions per page, and total of 50 pages.

this is the test format and i can't do anything about it. 

 

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