Forum .LRN Q&A: Some quickly thoughts about our experience with dotlrn.

1: Some quickly thoughts about our experience with dotlrn.

Posted by Jose Agustin Lopez Bueno on 11/18/04 07:39 PM

Some quickly thoughts about our experience with dotlrn.

At this moment we are running one instance of dot (oacs 5-1)
in production mode in University of Valencia (Spain). Our university is one example of a dot big instance. About 60000 students and 3000 teachers. I like to comment our experience to the community after one working year. We are very pleased with the platform and we have noticed the following strongpoints:

-The platform is very stable.
-A big and friendly developper community.
-We have constructed a solid base from which we are going to accelerate the future developments.

but we are throwing in lack several things like for the next year:

-Disk quotes (for persons and communities).
-Possibility of filing courses to unload of objects the data base at end of courses (I think of there are some package for Oracle related with this)
-Some problems with scalability. We detect the last year that several functions have bad performance, mainly in administration pages (acs_permissions*), with thousands of users in the DB. Perhaps the problem is a bad Postgresql optimization (we are using Postgres 7.4.5). For this, this year we have not loaded all the users. At this moment we have 26000 users and 3000 groups with a reasonably performance (I will like to know other elearning platform running with that load ) but we are beginning to experience performance degradation. We are thinking to moving our hardware from 2 to 4 CPUs (64 bits Opteron).
-Cluster possibilities.
-Many small bugs. I know we all are working in these. These are decreasing too quickly in cvs code. Thanks to all!

You can see our instance in http://pizarra.uv.es

Best regards,
Agustin

2: Re: Some quickly thoughts about our experience with dotlrn. (response to 1)

Posted by Rocael Hernández Rizzardini on 11/19/04 12:19 AM

Thanks for you feedback Jose,
Well, disk quotes, meaning limit the amount of data to be stored in a given fs instance is important.
Scalability is as well an important issue.

I don't understand this:
-Possibility of filing courses to unload of objects the data base at end of courses (I think of there are some package for Oracle related with this)

You mean, erasing content after the course is finished? if yes, our experience has shown that keeping the content makes the system more atractive for the users, in the long term, the students will go back to their old clases to grab some information that might be useful for them, and that sort of things make the use of .LRN more attrative for the end users. In general, you want to keep the history of the courses given, and keep growing you resources to be able to host that information, Galileo has almost 4 years of past courses on its installation.

3: Re: Some quickly thoughts about our experience with dotlrn. (response to 1)

Posted by Alfred Essa on 11/19/04 03:23 AM

Agustin, thank you for sharing your experience! Out of curiosity can you please give full specifications of your hardware. How much RAM etc.

4: Re: Some quickly thoughts about our experience with dotlrn. (response to 3)

Posted by Jose Agustin Lopez Bueno on 11/19/04 08:49 AM

Hello again!

>I don't understand this:
>-Possibility of filing courses to unload of objects the data base at end of courses (I think of there are some package for Oracle related with this)

Well, we are detected that one of the performance problems in a big installation is the number of objects in the DB. I know to store the courses history for several years is very attractive but we are scared about performance. Do you archive the old classes or keep it online like a normal class?

>Agustin, thank you for sharing your experience! Out of curiosity can you please give full specifications of your hardware. How much RAM etc.

Aolserver -> Dual Opteron 1.5 GHz 4 GB RAM SCSI local disk
Postgres -> Dual Opteron 2.0 GHz 4 GB RAM SCSI fiberchannel

Other thing: We are thinking of in develop something for the files quote system. Are there any thing implemented?
Any idea? What would be the best way to do that?

Regards,
Agustin

5: Re: Some quickly thoughts about our experience with dotlrn. (response to 4)

Posted by Rocael Hernández Rizzardini on 11/19/04 11:19 PM

>Do you archive the old classes or keep it online like a normal class?

Yes, we do, and I dont think the number of objects will decrease your performance, some procedures are related to decrease of performance (like class instantiation), but not the amount of objects per se.

For fs ideas look at:
http://openacs.org/forums/message-view?message_id=213667