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ShiftBit asked a question on 13 May 2014 11:21 AM

We have been having issues lately with CRM due to sql blocking.  After doing some digging, I ran across this article.  It mentions the AX product, rather than just regular CRM, but Im curious if this applies or not?

http://blogs.msdn.com/b/axsupport/archive/2011/09/22/severe-sql-locking-and-blocking-on-dynamics-ax.aspx?Redirected=true

In our case, this setting is off...so if this applies, it might explain why the constant blocking that comes up during even moderate load

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Peter72 responded on 13 May 2014 1:12 PM

Not officially, but a common recommendation (also directly from MS) to improve performance and reduce db-locks.

Regards,

Peter

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Joshua Thompson - McGladrey responded on 14 May 2014 7:13 PM

RCSI isn't a setting to improve performance. If you are going to turn on RCSI you need to understand the implications if doing so. It will greatly increase the load on your tempdb and you need to account for that. Every row in your db is versions with RCSI it is NOT the same as setting transaction isolation level = read committed.

Here is a brief article about RCSI you should read and understand. msdn.microsoft.com/.../tcbchxcb(v=vs.110).aspx

I would also look to understand what your blocking issue is caused by. Is it a particular table? User? Application? Time of day?

 Joshua Thompson
 Sr. Associate - Technology Services

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Peter72 responded on 14 May 2014 9:28 PM

Josh, I totally agree with your statement.

My answer was a bit short, and I know the article you mentioned.

And yes, first of all you should find the root cause of the blocking issue(s) and resolve them if possible.

However, in some cases we saw massive performance improvements. Mostly when a lot of scheduled interface jobs and/or a lot of plugins worked on the same entities.

Regards, Peter

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Joshua Thompson - McGladrey responded on 15 May 2014 7:45 AM

Peter, my reply was more directed at the OP than you, sorry if it came across the other way around.

 Joshua Thompson
 Sr. Associate - Technology Services

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Peter72 responded on 15 May 2014 8:17 AM

Josh, don't worry, I did not construed it this way :-)

Best Regards

Peter

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ShiftBit responded on 15 May 2014 10:17 AM

This article on Technet as part of other Dynamics CRM-specific optimization steps, suggests enabling Read Committed Snapshot isolation to avoid deadlocks

social.technet.microsoft.com/.../13661.dynamics-crm-2011-quick-optimization-guide.aspx

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Peter72 responded on 15 May 2014 10:41 AM

I confirm that we could reduce the number of deadlocks significantly by that. But as Josh mentioned, you should try to find out and eliminate the root cause. In our project, some long running interfaces (built with Scribe) causes these deadlocks.

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Peter72 responded on 15 May 2014 10:41 AM

I confirm that we could reduce the number of deadlocks significantly by that. But as Josh mentioned, you should try to find out and eliminate the root cause. In our project, some long running interfaces (built with Scribe) causes these deadlocks.

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Suggested Answer
Peter72 responded on 13 May 2014 1:12 PM

Not officially, but a common recommendation (also directly from MS) to improve performance and reduce db-locks.

Regards,

Peter

Reply
Suggested Answer
Joshua Thompson - McGladrey responded on 14 May 2014 7:13 PM

RCSI isn't a setting to improve performance. If you are going to turn on RCSI you need to understand the implications if doing so. It will greatly increase the load on your tempdb and you need to account for that. Every row in your db is versions with RCSI it is NOT the same as setting transaction isolation level = read committed.

Here is a brief article about RCSI you should read and understand. msdn.microsoft.com/.../tcbchxcb(v=vs.110).aspx

I would also look to understand what your blocking issue is caused by. Is it a particular table? User? Application? Time of day?

 Joshua Thompson
 Sr. Associate - Technology Services

  Follow me on Twitter My LinkedIn Profile

Reply