[Building Sakai] Why hasn't Recent Announcements slowed your performance?

[Keli Sato Amann]

Thanks Matthew. Jing is going to be looking at Recent Announcements to see if any of the JIRAS below will help us with 2.6, as we will probably not upgrade versions until next summer. Julian, not sure if you'll be working with her, re the message date index Matthew mentions below.

It does not happen all the time, but when it happens it becomes slow for the entire campus. I hope I'm not misquoting him, but Julian suspects that certain users with hundreds of active sites, or perhaps one user, might set this off.

Keli Amann
User Experience Specialist 
Academic Computing Services, Stanford University

----- Original Message -----
From: "Matthew Jones" <matthew at longsight.com>
To: "Keli Sato Amann" <kamann at stanford.edu>
Cc: "Sakai Dev" <sakai-dev at collab.sakaiproject.org>
Sent: Friday, April 27, 2012 2:45:35 PM
Subject: Re: [Building Sakai] Why hasn't Recent Announcements slowed your performance?


The default of the recent announcements is only to show 10 days. 
https://source.sakaiproject.org/svn/announcement/trunk/announcement-tool/tool/src/webapp/tools/sakai.synoptic.announcement.xml 


I can see some fixes where it might not have been respecting this limit in the UI pre 2.7, but you seem to say this is happening all of the time? 


https://jira.sakaiproject.org/browse/SAK-13116 
and possibly 
https://jira.sakaiproject.org/browse/SAK-12876 

I've never seen a significant slowdown in a 2.7+ instance related to the synoptic announcement box. In most instances it defaults to 10 days. At Michigan these were patched into our 2.6 instance almost immediately back in 2009. 


I'm almost entirely sure now that this field is used for the sorting, especially after 
https://jira.sakaiproject.org/browse/SAK-11544 (though I don't think that touched announcement) 


I'd maybe have your dba check to make sure the message date index is correct and valid. The query to return messages based on the last 10 days should be quick. 



I tested it on a DB with 20K announcements and it was instant. 


I think it was noted that the actual announcements should be cached, but I don't think this is related? 
https://jira.sakaiproject.org/browse/SAK-21511 


-Matthew 


On Fri, Apr 27, 2012 at 4:47 PM, Keli Sato Amann < kamann at stanford.edu > wrote: 


Hello 
One of the issues slowing performance on our campus is the fact that Recent Announcements widget queries old sites, which are not likely to have recent announcements. After a particularly slow day, we recently removed the Recent Announcements widget altogether and things seemed to be much better. We made a local fix to our 2.6 instance which prevented hidden sites from being included in search of Announcements, but few people opt to hide sites so we didn't have enough confidence that this alone would improve performance. 

There are a few ways we could address this so we can add that widget back 
1) encourage users to hide sites with improved design 
2) force course sites to be hidden after 2 years (we could do it more frequently, but some course admins like to refer to older sites), but make it more obvious how to find these hidden sites. 
3) make course sites that are older than a quarter not show up in Recent Announcements search, regardless of whether they are hidden or active. 

Regardless of which direction we decide to go, we are surprised that this hasn't been a problem for other schools who have used the CLE longer and with more classes. We suspect it may be because other schools remove rosters from course sites and include new rosters every term, such that students don't have active sites from more than a year ago. Here, we create new sites for each new term a course is taught so students and instructors have 4 or more courses (some local admins have hundreds of courses). Perhaps you also encourage instructors to unpublish sites after the term--we don't here, because we think students like to refer to old course materials as they prep for new course, or as they prepare to leave and need to put a portfolio together, but I suppose we could force them to gather material before the term. 

If anyone who uses Recent Announcements in My Workspace has more thoughts on this, we'd be curious. 

Keli Amann 
User Experience Specialist 
Academic Computing Services, Stanford University 
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