Students viewing the assignment list in a course experience extremely slow performance - upwards of 10 seconds to render the page. The course has approx 166 participants, and there are 12 assignments defined (of which 10 are currently open).
Analysis of the mysql logs (attached) for the period when the assignments list was rendered show:
3780 queries of the form:
select SAKAI_ALIAS.ALIAS_ID,SAKAI_ALIAS.TARGET,SAKAI_ALIAS.CREATEDBY,SAKAI_ALIAS.MODIFIEDBY,SAKAI_ALIAS.CREATEDON,SAKAI_ALIAS.MODIFIEDON from SAKAI_ALIAS where ( ALIAS_ID = NULL )
66 queries of the form:
select XML from SAKAI_PREFERENCES where ( PREFERENCES_ID = 'userid' )
38 queries of the form
select XML from ASSIGNMENT_ASSIGNMENT where ( ASSIGNMENT_ID = ? )
(even though there are only 12 assignments in this site)
Performance is now acceptable on our staging 2.2 server with our migrated 2.1.x production db.
To QA this on a QA server would require a realistic data set of a reasonable size (several hundred students in a course site with > 10 assignments listed, and existing assignment submissions).
Zhen Qian June 21, 2006 at 12:59 PM
Please refer to the progress of for the remaining sakai_preferences query issue.
Zhen
Stephen Marquard June 19, 2006 at 1:53 PM
Reopening this for the SAKAI_PREFERENCES issue (and downgrading priority, as the performance impact of this is lower). However, if you'd like to resolve this issue and open another one for the SAKAI_PREFERENCES behaviour, please go ahead.
Stephen Marquard June 19, 2006 at 1:50 PM
The major problem (queries to SAKAI_ALIAS) has been resolved. However, I'm still seeing lots of queries to SAKAI_PREFERENCES like this:
select XML from SAKAI_PREFERENCES where ( PREFERENCES_ID = 'marquard' )
In the example I tested (logging just the queries generated after clicking on the tool reset icon), there were 127 of these - a large number of identical queries sequentially upfront, and then about 4 to 5 following each assignment query.
Zhen Qian June 19, 2006 at 11:24 AM
Close this ticket for now and track the issue in SAK-4586.
Students viewing the assignment list in a course experience extremely slow performance - upwards of 10 seconds to render the page. The course has approx 166 participants, and there are 12 assignments defined (of which 10 are currently open).
Analysis of the mysql logs (attached) for the period when the assignments list was rendered show:
3780 queries of the form:
select SAKAI_ALIAS.ALIAS_ID,SAKAI_ALIAS.TARGET,SAKAI_ALIAS.CREATEDBY,SAKAI_ALIAS.MODIFIEDBY,SAKAI_ALIAS.CREATEDON,SAKAI_ALIAS.MODIFIEDON from SAKAI_ALIAS where ( ALIAS_ID = NULL )
66 queries of the form:
select XML from SAKAI_PREFERENCES where ( PREFERENCES_ID = 'userid' )
38 queries of the form
select XML from ASSIGNMENT_ASSIGNMENT where ( ASSIGNMENT_ID = ? )
(even though there are only 12 assignments in this site)