Forum .LRN Q&A: Anybody experiencing memory leaks?

Posted by Deds Castillo on 02/05/03 07:55 AM

We have an installation of dotLRN running on Postgres with more than 1,000 users with fair activity daily. At one point memory use of nsd peaked at 500MB and it's shows no sign of going down. Does anyone else experience this?

Relevant Information:
AOLserver 3.3.1ad13
Postgresql 7.2

2: Re: Anybody experiencing memory leaks? (response to 1)

Posted by Roberto Mello on 02/05/03 08:09 AM

We're seeing the same behavior with the openacs.org installation since we moved to PG 7.2. We haven't tracked it down yet, but I suspect it has something to do with the libpq and the driver.

We'll keep everyone posted.

-Roberto

3: Re: Anybody experiencing memory leaks? (response to 1)

Posted by Deds Castillo on 02/05/03 09:03 AM

Roberto,

Thanks. What do you mean by similar? What's the max memory consumption you've observed so far?

4: Re: Anybody experiencing memory leaks? (response to 3)

Posted by Jeff Davis on 02/05/03 09:35 AM

We saw openacs.org at about 750mb the other day and 375mb yesterday. It seems to grow by about 50mb a day (on about 25000 hits). Its possible that its a leak in nsfts or from the postgres driver (both of which were changed in the last couple weeks), but we (Roberto really) are still looking into it.

5: Re: Anybody experiencing memory leaks? (response to 1)

Posted by Alfred Essa on 02/05/03 09:31 PM

Deds, I am curious to know how you are using dotLRN. What's the site and what types of users. Is it in production or testing? Thanks,Al

6: Re: Anybody experiencing memory leaks? (response to 1)

Posted by Deds Castillo on 02/06/03 03:53 AM

Al,

It's production. http://www.robs.org. This is used by River Oaks Baptist School in Houston for all their students, teachers and even parents. Almost all features are being used and it's safe to say that it gets a fair amount of hits per day because the students are being trained batch by batch on a per classroom(?) level.

7: Re: Anybody experiencing memory leaks? (response to 1)

Posted by Jun Yamog on 02/06/03 04:13 AM

Hi Deds,

Does testing on devux1 behave similarly on liveux1? Maybe you can just pound some robs pages on devux1 with ab. It may be not dotLRN specific. The pg driver may also be not the latest, try upgrading. Are the other 7.2.x sites running ok?

8: Re: Anybody experiencing memory leaks? (response to 1)

Posted by Caroline Meeks on 02/06/03 04:19 AM

Deds,

This is very exciting. The site looks great from the outside. :) Having an 5th grader myself I've often thought about the potential for dotLRN in primary education.

I'm sure many people would be interested in how the UI and functionality is being used in the K-12 environment and any case study on how students of different ages are using it and parent/school communication would be wonderfull.

Is there anyone at the school who would be willing to serve as a reference when other K-12 schools express interest?

9: ROBS (response to 1)

Posted by Alfred Essa on 02/06/03 05:13 PM

Deds,

This is fabulous. Congratulations. Keep us apprised of how the site evolves. The following types of community applications, linking parents, students, and teachers, is very exciting:

"In the future, you will be able to create a calendar for your family that details your child's or children's activities and homework assignments. You will also be able to become part of certain online community groups within the school."

10: Re: Anybody experiencing memory leaks? (response to 1)

Posted by Jorge Garcia on 02/06/03 05:39 PM

Deds,
Which hardware are you using to support dotLRN there?
Processors, RAM, MHz, several computers or just one, same computer for PG and Aolserver or several servers?
We are very interested in how many hardware it's needed to serve a school.

/Jorge

11: Re: Anybody experiencing memory leaks? (response to 1)

Posted by Jorge Garcia on 02/06/03 05:43 PM

Caroline,
Could you explain to an uninformed what is a K-12 environment or a K-12 school?
😉
Thanks.
/Jorge

12: Re: Anybody experiencing memory leaks? (response to 1)

Posted by Deds Castillo on 02/07/03 03:53 AM

Jun,

Will start testing on non-dotlrn sites but pg7.2 sites first so that we can isolate. Ham is already doing that.

Caroline,

Thanks. Regarding your question about reference, I'll bring that up and will post here again for their answer.

Al,

Thanks. I would say that the future goal would really be seamless integration. Will just keep you updated on developments into the site. I'll try and get permission to set up a guest account so that others can also browse the dotlrn specific stuff.

Jorge,

I'm not exactly sure on the hardware specs. Jun Yamog should know as he coordinated the purchase of that. I think it's a dual proc Pentium III 500 with 1GB RAM. But since they are still on their "learning stage" and hits are only of fair amount, both AOLserver and PG are housed inside the same box. Of course there are plans to change the structure if ever the need for it comes in the future.

13: Re: Anybody experiencing memory leaks? (response to 1)

Posted by Jun Yamog on 02/07/03 05:03 AM

Hi,

Nope I did not coordinate the purchase of that server. It was purchased before I got to II. I just basically fixed the server, reinstall Linux and friends, config the server, transported it to a data center and put it in a rack and got the 2nd CPU running.

Its an old VA Linux back in the days VA wasn't much that known yet. Dual P3 500 - Katmai core only. 1GB Ram, 4 Atlas IV on RAID 5 config. Still running RH 6.2. The server also has other OpenACS sites and some plain aolserver sites.

It did handle the several OpenACS sites well. OpenACS sites just tend to eat RAM, not much CPU.