FIX: Writelog Timeout When Replicating Cross-Database Transactions (181557)
The information in this article applies to:
This article was previously published under Q181557
BUG #: 17830 (NT: 6.5)
SYMPTOMS
If a published table is modified as part of a two-phase commit transaction,
SQL Server may become sluggish or begin to log writelog timeout messages to
the SQL Server errorlog. The writelog timeout message will look like:
writelog: timeout, dbid 7, dbstat2 0x100002(0x100002), q1/q2 0/0,
owner=17, waittype=0
The problem is more likely to occur on a computer with a single or dual
processors, where the default 'SMP Concurrency' option would throttle SQL
Server to using only a single processor. Computers with more processors may
still exhibit short bottlenecks, but will be much less likely to see the
writelog timeout messages.
Internally, SQL Server uses two-phase commit protocol when performing any
cross-database transactions. Two-phase commit may also be done
programmatically through DB-Library applications, or applications using
Microsoft Transaction Server (MTS).
CAUSE
When the logreader task runs sp_repldone and finds a pending two-phase
commit transaction, it waits for a short period of time to allow the
transaction to complete. During this time, it holds an internal resource
used for synchronization, thus preventing other processes from running.
Processes attempting to write log records may therefore see timeout
messages.
WORKAROUND
To work around this problem, change the logreader to a Recurring task,
rather than Auto Start. Even if the task is run every minute, the frequency
with which sp_repldone is run will decrease, thereby minimizing the chance
of stalling on a transaction in a prepared state.
STATUS
Microsoft has confirmed this to be a problem in SQL Server 6.5. This problem has been corrected in Service Pack 5a for Microsoft SQL Server 6.5.For more information, click the following article number to view the article in the Microsoft Knowledge Base: 197177 INF: How to Obtain SQL Server 6.5 Service Pack 5a For more information, contact your primary support provider.
Modification Type: | Major | Last Reviewed: | 3/14/2006 |
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Keywords: | kbBug kbfix kbSQLServ650sp5fix KB181557 |
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