Login 1000 student at a time on one quiz

回复: Re: 回复: Re: Login 1000 student at a time on one quiz

by Frankle Lee 李智高 -
Number of replies: 4

Hi, here is my answer:
I conduct all my 600-user-final exams on moodle 2.6 not 1.9

It seems to me that 50MB ram for every user is quit true to my situation, so I guess more than 60Gb ram should be OK for 1000 users. And of course, it also depends on the CPU, Cache, and harddisk speed. More Powerful CPU, faster Cache and SSD will help to reduce the ram requirement.

The last question, all my 600 students will login and click start quiz then load the first page of questions within a period of 3-5 minutes.

The loading time at the beginning will last longer, sometimes over 30 seconds, but once the quiz has began, the loading time for the next page will be much faster because of the clicking time for next page would be various for different users.

Average of ratings: -
In reply to Frankle Lee 李智高

Re: Login 1000 student at a time on one quiz

by Visvanath Ratnaweera -
Picture of Particularly helpful Moodlers Picture of Translators
Hi Frankle Lee 李智高

Thanks for providing those information.

> I conduct all my 600-user-final exams on moodle 2.6 not 1.9

I knew that. The point i wanted to bring was that your server might handle close to 1000 users taking the same exam if you were running Moodle 1.9. Note that this discussion is about Moodle 1.9.

> It seems to me that 50MB ram for every user is quit true to my situation, so I guess more than 60Gb ram should be OK for 1000 users.

Your argument is that, since your machine handle close to 600 users with 32 GB, raising it to 64 GB it might reach 1000 users. Possible, if the RAM was and will remain the bottle neck. That is why I asked about monitoring.

> And of course, it also depends on the CPU, Cache, and harddisk speed. More Powerful CPU, faster Cache and SSD will help to reduce the ram requirement.

Generally true. But you will notice the difference only if you help the bottle neck.

> The last question, all my 600 students will login and click start quiz then load the first page of questions within a period of 3-5 minutes.
>
> The loading time at the beginning will last longer, sometimes over 30 seconds,

Your machine is very powerful, I must say. Still 30 sec can make an examination candidate nervous. There were various tricks discussed in this forum to flatten the initial peak, like delaying each computer room by 5 min, and/or assigning the exam a very long password, ...

> but once the quiz has began, the loading time for the next page will be much faster because of the clicking time for next page would be various for different users.

Yes, that is to be expected. Also because the various caches continue "learning".

All that said, you are trying to put a cap on the number of users:
Is there a way to limit the number of online users for a moodle site?
https://moodle.org/mod/forum/discuss.php?d=317711
Is it related in any way?
Average of ratings: Useful (2)
In reply to Visvanath Ratnaweera

回复: Re: Login 1000 student at a time on one quiz

by Frankle Lee 李智高 -

> I conduct all my 600-user-final exams on moodle 2.6 not 1.9

I knew that. The point i wanted to bring was that your server might handle close to 1000 users taking the same exam if you were running Moodle 1.9. Note that this discussion is about Moodle 1.9.

> It seems to me that 50MB ram for every user is quit true to my situation, so I guess more than 60Gb ram should be OK for 1000 users. 

I read this 50mb per user many years ago, it looks like from the documentation of 1.9, but still true to me right now, so I always keep that in mind.

Your argument is that, since your machine handle close to 600 users with 32 GB, raising it to 64 GB it might reach 1000 users. Possible, if the RAM was and will remain the bottle neck. That is why I asked about monitoring.

I will try to monitor the bottle neck next time, but usually a 600 user exam only happen in mid term or finals, so need to wait for next semester. Now is the summer vacation, YEAH!!!

 

> And of course, it also depends on the CPU, Cache, and harddisk speed. More Powerful CPU, faster Cache and SSD will help to reduce the ram requirement.

Generally true. But you will notice the difference only if you help the bottle neck.

> The last question, all my 600 students will login and click start quiz then load the first page of questions within a period of 3-5 minutes.
> 
> The loading time at the beginning will last longer, sometimes over 30 seconds, 

Your machine is very powerful, I must say. Still 30 sec can make an examination candidate nervous. There were various tricks discussed in this forum to flatten the initial peak, like delaying each computer room by 5 min, and/or assigning the exam a very long password, ...

Thanks for your tricks, I will try it later. the long password is a Brilliant tricks!

My server is not so powerful, it works for my for over 2 years. And it's very cheap, about USD3000.00, now even much cheaper I am sure.

> but once the quiz has began, the loading time for the next page will be much faster because of the clicking time for next page would be various for different users.

Yes, that is to be expected. Also because the various caches continue "learning".

All that said, you are trying to put a cap on the number of users:
Is there a way to limit the number of online users for a moodle site?
https://moodle.org/mod/forum/discuss.php?d=317711
Is it related in any way?

Actually I am working on a project to invite teachers from other school to use our platform to build and share courses with us. In this case, I prefer more control of the user numbers from each school.

Average of ratings: -
In reply to Frankle Lee 李智高

Re: 回复: Re: 回复: Re: Login 1000 student at a time on one quiz

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

I might add that I am entirely guilty of the "50MB per user" figure. It was worked out on the basis of watching some monitoring over a period of about 10 minutes on one of my live systems. It was meant to provide an "order of magnitude" figure rather than a hard rule. I suspect it is a bit on the high side. However, some teacher/admin activities can consume a LOT more memory so I still think it's about right. 

As has been said, if performance is poor there is more to go wrong than not having enough ram. It is easy enough to see if a system is going into swap and it is easy enough to check the load figures. However, just guessing (what we get asked to do all the time in this forum) is not really going to help anyone. 

Average of ratings: Useful (1)