FIX: Thread Deadlock Causes Checkpoint to Hang in tempdb (131662)
The information in this article applies to:
- Microsoft SQL Server 4.2x
This article was previously published under Q131662
BUG# NT: 9992 (4.21a)
SYMPTOMS
When you execute tempdb-intensive queries involving sorting, under very
narrow conditions, a thread deadlock can occur during sort cleanup. This is
often difficult to identify because the visible symptoms are ambiguous.
However the observed characteristics include a general slowdown, increased
blocking, and the checkpoint process hanging in tempdb. It is often
possible to login to SQL Server with ISQL.EXE, do SELECTs from user
databases, but not possible to run data modification statements in tempdb.
CAUSE
Worker threads become deadlocked when deallocating extents during sort
cleanup.
WORKAROUND
The problem is exceedingly narrow in scope and very rare. Because of this
and the ambiguous symptoms, this problem should not be suspected until
close study has ruled out all other problems. This would include verifying
dbcc newalloc and dbcc checkdb are error free on all databases, no errors
exist in the SQL errorlog, and any observed blocking or slowdown is not
caused by conventional concurrency issues. Slightly changing the
application, queries, platform, or SQL configuration may avoid the problem.
STATUS
Microsoft has confirmed this to be a problem in SQL Server version 4.21a.
This problem was corrected in the latest U.S. Service Pack for SQL Server
version 4.21a. For information on obtaining the Service Pack, please
contact your primary support provider.
| Modification Type: | Major | Last Reviewed: | 3/24/2000 |
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| Keywords: | kbbug KB131662 |
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