SharePoint 2007 and DST Change

Wednesday, 12 March 2008 13:29 by RanjanBanerji

So we all experienced the DST change this past weekend.  Though the government has made DST last longer the basic concept remains the same.  One day in spring the time jumps forward by an hour and then one day in fall it jumps back an hour.  Computer systems have been handling this event for decades.  Even systems that were built ages ago that could not handle the Y2K issue could handle the DST change.

Ah! but not anymore.  SharePoint 2007 has some really cool built-in features (please note the sarcasm).  When the DST change occurs SharePoint is completely clueless of what happened.  We had a few content deployment jobs scheduled to run every minutes.  These jobs took an average of about 5 minutes to run.  After this weekend these jobs started taking an average of about 1 hour and 5 minutes to run.  It was too much of a coincidence for all jobs to start taking an extra hour just after the DST change.

After some analysis I figured I might as well restart the Windows SharePoint Timer Service.  Well that fixed the problem.  Well not really.  What will happen this fall when the DST time switches back?  So I was convinced I made a mistake in building our servers.  I must have missed some patch or hotfix.  Nope, that was not the case.  I came across Microsoft's knowledge base article 938663 which then convinced me that what I was observing is a feature not a bug :-).  The article says:

"The Windows SharePoint Timer service does not update its internal time when Microsoft Windows makes the transition from standard time to DST or from DST to standard time. Therefore, after you apply this hotfix, you must restart the Windows SharePoint Timer service after each transition from standard time to DST and after each transition from DST to standard time. If you do not restart the Windows SharePoint Timer service, timer jobs that you schedule may be delayed. Or, they may fail."

So, let me get this right.  You apply a hotfix then twice a year you go to each SharePoint server and restart it's timer service.  Absolutely amazing.  Obviously a better solution would be to write a script or service to do this for you if you are running multiple large farms.  One more reason some people call SharePoint a development platform ;-)

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Login failed for user 'NT AUTHORITY\SYSTEM'. SharePoint 2007

Friday, 8 February 2008 23:08 by RanjanBanerji

Note: The error I am talking about can occur due to various reasons.  This post is specific to SharePoint 2007

On our SQL Server box we got hundreds if not thousands of Login failed for user 'NT AUTHORITY\SYSTEM' errors in the event log.  Looking at the SQL Logs I determined that these were Error: 18456, Severity: 14, State 16.  Great so what does that mean?

A little more research showed that SharePoint runs a job on SQL Server that deletes expired Sessions from the Shared Services Database.  If you had been moving databases, removing SSPs, etc you may end up in a situation where an old SSP Shared Service Database no longer exists but the job to delete its expired sessions is still running.  Aha!!!!! and there you have this error showing up every minute of so.

To fix the problem go to SQL Server Management Studio, Go to SQL Server Agent, Open Jobs and disable or delete jobs that point to Shared Services databases that no longer exist.