Forum .LRN Q&A: Assessment is killing our .LRN.

Posted by Dario Roig on 02/16/09 12:52 PM

Hi guys! we have many problems with package assessments. The package have lots of options and two features very important to us: the first autocorrection with score and feedback, the second import/export in format QTI. However, it has some disadvantages, when the professor open one assessment to 20 or 30 students in classroom and the students send at the same time their responses generate deadlocks in the database and all system down.

Valencia University instalation:
Postgresql: 8.2.10
Aolserver: 4.5.0

Solutions:
- Change assessment by survey. We are thinking development the features similars to assessment in survey.
- Modify assessment to avoid big transactions

Has anybody the same problem with assessment?

Greetings

2: Re: Assessment is killing our .LRN. (response to 1)

Posted by Gustaf Neumann on 02/16/09 01:58 PM

What version of OpenACS are you using?

In case, you are not using the most recent content-repository, you should consider the following change
http://fisheye.openacs.org/changelog/OpenACS/openacs-4/packages/acs-content-repository?cs=MAIN:gustafn:20081217193526

Please report back, if this helps
-gustaf neumann

3: Re: Res: Assessment is killing our .LRN. (response to 1)

Posted by Dario Roig on 02/17/09 07:56 AM

Hi Gustaf! I've done a diff with our code and we have the same version. The line "db_dml lock_objects "LOCK TABLE acs_objects IN SHARE ROW EXCLUSIVE MODE"" is commented.

Thanks for your fast response, We will find solutions and We will post in this post!!

4: Re: Res: Assessment is killing our .LRN. (response to 1)

Posted by Hector Amado on 02/17/09 07:07 PM

Hi Dario!, if you have log messages like:
Warning: db_exec: longdb 10594180 nsdb0 select .... get_sorted_choices ...
get_sorted_choices_with_feedback ....

make sure you have this update:
http://cvs.openacs.org/cvs/openacs-4/packages/assessment/tcl/as-item-type-mc-procs-postgresql.xql?sortby=author&view=log
rev 1.5

Best Regards,

5: Re: Res: Assessment is killing our .LRN. (response to 1)

Posted by Dario Roig on 02/18/09 03:31 PM

Hi Hector!
In this link you can view our file
http://aulavirtual.uv.es/ficheros/view/dotlrn-uv-packages/assessment/asxitemxtypexmcxprocsxpostgresql.xql

We have rewritten this select for best performance.

Thanks by advice

6: Re: Res: Re: Res: Assessment is killing our .LRN. (response to 5)

Posted by Hector Amado on 02/19/09 09:56 PM

Hi Dario! , you can test with the new revision in as-item-type-mc-procs.tcl, http://cvs.openacs.org/cvs/openacs-4/packages/assessment/tcl/as-item-type-mc-procs-postgresql.xql?revision=1.5&view=markup&sortby=file this is for multiple choice questions.
Try updating assessment package.

In the new revision you don't use r2.revision_id as content_rev_id, r2.title as content_filename and i.content_type

Best regards,