[Building Sakai] Dashboard - dash_context table

[Jim Eng]

On Sep 20, 2012, at 5:07 PM, Omer A Piperdi wrote:

> We get this message
> 
> 2012-09-19 09:20:06,589  WARN Dashboard Event Processing Thread org.sakaiproject.dash.logic.DashboardLogicImpl - Failed attempt to retrieve news events in context (!admin) for new user (xxxxx)
> 
> when admin try to add user to a certain site..

Interesting.  Is that when admin adds a user to the admin workspace or any site? Can you tell whether this results in the user missing some updates in dashboard?  

My first impression is that if this is for the admin workspace, we should create a exception that avoids trying to add items to the dashboard for that site.  If it relates to admin adding a user to a different site, we will need to dig deeper and figure out why that would be a problem. 


> We are also having issues with SQLRecoverableException and not sure what is causing yet so far..
> 
> Do you know what might be causing this?
> 
> 2012-09-19 12:04:44,564  WARN Dashboard Event Processing Thread org.sakaiproject.dash.dao.impl.DashboardDaoImpl - deleteCalendarLinksBefore: Error executing query: class org.springframework.dao.DataAccessResourceFailureException:PreparedStatementCallback; SQL [delete from dash_calendar_link where item_id in (select id from dash_calendar_item where calendar_time < ?) and sticky=? and hidden=?]; IO Error: Connection timed out; nested exception is java.sql.SQLRecoverableException: IO Error: Connection timed out

I think this query occurs during the "expire and purge" task that is supposed to be handled by a single server in the cluster.  I just created a JIRA ticket for an issue reported by Columbia that may be related"

https://jira.sakaiproject.org/browse/DASH-245

Columbia was seeing contention in the database especially during the periodic task that updates repeating events.  We are preparing to work on that, but we think it will require use of a clustered environment for load testing, and we are not sure how soon we can schedule use of the load-test environment at Michigan.  


> 
> Thanks
> Omer
> On 9/20/2012 3:43 PM, Jim Eng wrote:
>> Hi Omer,
>> 
>> Comments inline below.
>> 
>>> I am wondering how the entries in dash_context table are added. We have a lot less sites which has Dashboard tool in it about 100 sites and dash_context table has more that 1400 entries.
>> 
>> We expect to deploy dashboard as the default landing page in MyWorkspace for every user, and the users expect to see relevant info for all sites they belong to.  So, dashboard watches sakai events for all sites, not just sites that have the dashboard tool.  Dashboard uses the dash_context table to keep track of the sites where the events occurred. A record is added to dash_context whenever an event is processed for a site that does not already have a record there.  Eventually there would be a record in dash_context for every active site.
>> 
>>> 
>>> Does it add a site to dash_context table during the creation even if the site does not have Dashboard tool in it?
>>> 
>>> We are also seeing following message in log..
>>> 
>>> 2012-09-19 09:20:06,589  WARN Dashboard Event Processing Thread org.sakaiproject.dash.logic.DashboardLogicImpl - Failed attempt to retrieve news events in context (!admin) for new user (xxxxx)
>> 
>> Are you seeing lots of these, or just a few at startup?  It may be something special about the "!admin" site that doesn't work in dashboard.
>> 
>>> 
>>> Also in Confluence documentation..
>>> 
>>> https://confluence.sakaiproject.org/display/DASH/Configuring+dashboard
>>> 
>>> There is a property_name PROP_DAYS_BETWEEN_HORIZ0N_UPDATES..
>> 
>> It would appear that there's a zero instead of 'O' in horizon in all the relevant places.  Maybe we can fix that at some point, but for now, the correct property name uses a zero at that point.  Sorry.
>> 
>> 
>>> 
>>> There is a 0 (zero) in HORIZON instead of an O, which is the correct property_name?
>> 
>> 
>> Thanks.
>> 
>> Jim
>> !DSPAM:2294,505b7ffe192265700014244! 
>