[Portfolio] Slow-downs

[Marc Zaldivar]

Sean,

Teggin said that yesterday in the call you were discussing the ³form
searching slow-down² issue.  Yes, VT hit this one pretty hard this semester,
and I know Michigan has also been faced with a growing issue from this.  We
spent a couple of hours on the phone with Noah talking over some solutions,
and though I didn¹t talk to him, I know our dev group also talked with Chuck
Hedrick too.

The breakdown of the issue came for us because we are using so many of the
³UROP²-type portfolios for our templates, which are basically using form
pages for each tab of a final display portfolio, in our case sometimes as
many as 17 or 18 different forms for each complete portfolio (sometimes they
were limitlessly repeatable, so some students may have had upwards of 30
forms to put into different slots in the template).  Each time the ³Save
Changes² button is hit, it would search the database 5 times per slot per
form instance, making that sometimes 1000s of searches per creation attempt.
When you do this in a demonstration with 25-30 kids in the room (ok, now
everyone push ³Save Changes...²), it¹s fatal.  Even without that, given the
activity ramp-up we are seeing, we were seeing an average of 60+ seconds for
new users, and for folks like me that own a lot of forms, it was often
beyond our threshold for database link-up at 10 minutes or something
ridiculous.  So, big big problem that is only going to get bigger as we
expand.  (We had at that time about 4k forms out of 250k items in the
database.)

Ultimately, we tested several solutions, with the big two being (1) a patch
that Noah/rSmart came up with that (I think) refined the search parameters
without limiting it to My Workspace, creating a cache that was searched
repeatedly rather than having to keep hitting the database time and again,
and (2) Chuck Hedrick¹s solution to limit all searching to the My Workspace
first.  Ultimately, #2 was faster on our test speeds.  We felt that maybe #1
would be a better long-term solution, but that it would take some real time
to refine that search protocol and build the cache effectively.  Hopefully,
we¹ll still work toward that ultimate solution.  However, we deployed #2 and
saw my admin account¹s wait time drop from 10+minutes to about 18 seconds.
Average users are now 2-5 seconds tops.  Much, much better so far.

Do you see any potential for problems if presentations are being created
from forms created through a matrix?  Mostly, I¹d assume that these forms
would be located in the various Portfolio Interaction folders, in the MW.
The one potential is for non-matrix portfolios, you¹d have to specify the
need to store forms in a folder in the MW rather than in a course drop box
or resource area.  

Just thought I¹d share our perspective on the issue.  Noah, please feel free
to detail out my all to0 non-tech-savvy description of your patch and what
it does!  

Marc Z
-- 
Marc Zaldivar, Ph.D.
2210A Torgersen Hall
Director, Virginia Tech Electronic Portfolio Initiatives        Blacksburg,
VA 24061-0292
Learning Technologies
540.231.8994
Virginia Tech      
marcz at vt.edu



-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://collab.sakaiproject.org/pipermail/portfolio/attachments/20090519/e1c3f598/attachment.html