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

Wed May 2 04:54:12 PDT 2012

As I recall, the issue we had with MOTD surfaced when we were looking at 
slowdowns and found it related in some way to logins and the 
announcement tool (which provides the MOTD). We had maybe 200 motds in 
the system, some with start and/or stop dates, and the query to figure 
out which announcement to show was taking some time, running many times 
during heavy login periods (since we have the motd on user's Home page 
in their my workspace). The query was faster when old motds were hidden 
rs just there but older, so we went through and deleted or hid all but 
the couple most recent motds in order to lessen the query load.

I think it helped - don't know if anything has changed since then to 
make this less useful. If you only have a few motds anyway it wouldn't 
be relevant.

John

Matthew Jones wrote:
> I remember Michigan did have some problems with MOTD either back in 
> 2.6 or early 2.7 if there were a lot of MOTD's. I'm not sure if that 
> was ever fixed, the problem went away or if they just kept cleaning up 
> the MOTD. This is the same tool as announcements.
>
> I don't ever remember any significant problems that directly pointed 
> back to any announcement queries, but maybe Adam does have some new 
> details related to the filing of that other ticket. Those queries 
> shouldn't be triggered by the synoptic announcements though, but would 
> be triggered by announcements in courses. (Where there is no date 
> restriction on the query)
>
> https://jira.sakaiproject.org/browse/SAK-21511 
> <https://jira.sakaiproject.org/browse/SAK-21511?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#issue-tabs>
>
> I'll let you know if I see anything else though. Do you have any 
> information about slow queries or frequent queries? Easy to generate 
> from a AWR report in Oracle. I'm not so sure from Mysql (probably 
> parsing general logs on ANNOUNCEMENT_MESSAGE).
>
> On Tue, May 1, 2012 at 5:24 PM, Keli Sato Amann <kamann at stanford.edu 
> <mailto:kamann at stanford.edu>> wrote:
>
>     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
>     <mailto:matthew at longsight.com>>
>     To: "Keli Sato Amann" <kamann at stanford.edu
>     <mailto:kamann at stanford.edu>>
>     Cc: "Sakai Dev" <sakai-dev at collab.sakaiproject.org
>     <mailto: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 <mailto: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
>     _______________________________________________
>     sakai-dev mailing list
>     sakai-dev at collab.sakaiproject.org
>     <mailto:sakai-dev at collab.sakaiproject.org>
>     http://collab.sakaiproject.org/mailman/listinfo/sakai-dev
>
>     TO UNSUBSCRIBE: send email to
>     sakai-dev-unsubscribe at collab.sakaiproject.org
>     <mailto:sakai-dev-unsubscribe at collab.sakaiproject.org> with a
>     subject of "unsubscribe"
>
>
>
>
> _______________________________________________
> sakai-dev mailing list
> sakai-dev at collab.sakaiproject.org
> http://collab.sakaiproject.org/mailman/listinfo/sakai-dev
>
> TO UNSUBSCRIBE: send email to sakai-dev-unsubscribe at collab.sakaiproject.org with a subject of "unsubscribe"

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://collab.sakaiproject.org/pipermail/sakai-dev/attachments/20120502/637cce08/attachment.html 