MSDTC and SQL Server 2005 Clustering

While searching for questions, Why MSDTC is required, in which it needs to be configured, is it must for SQL Clustering, etc. Please find below the analysis done by going through several forums and msdn articles,

References on Why MSDTC required for SQL Clustering:

< 1.       MSDTC and SQL Server on a cluster – http://blogs.msdn.com/b/sqlblog/archive/2006/10/06/msdtc-and-sql-server-on-a-cluster.aspx

< 2.       Before Installing Failover Clustering – http://msdn.microsoft.com/en-us/library/ms189910(v=sql.90).aspx

< 3.       Clustered SQL Server 2005: is MSDTC required? – http://blogs.technet.com/b/beatrice/archive/2007/04/23/clustered-sql-server-2005-is-msdtc-required.aspx

< 4.      How to configure Microsoft Distributed Transaction Coordinator on a Windows Server 2003 cluster – http://support.microsoft.com/kb/301600

< 5.       Is MSDTC Service necessary in SQLServer Cluster? – http://social.msdn.microsoft.com/Forums/en/sqldatabaseengine/thread/32b3cfac-1a09-4718-87be-c23c0f958012

 

Verdict:

a)      It is good to configure MSDTC while building cluster, but it is must when you configure SSIS, Notification, analysis services as well with database engine

b)      MSDTC is required to install cluster aware patches

c)       Don’t run MSDTC as standalone service as it may lead to corruption of data

 

References for error: 11009 “No passive nodes were successfully patched”,

< 1.      http://www.sql-server-performance.com/forum/threads/no-passive-nodes-were-successfully-patched.29031/

< 2.      http://www.mssqltips.com/sqlservertip/1668/updating-the-passive-node-in-a-sql-server-2005-cluster

 

Possible Solutions:

a)      Read readme files comes with Service Pack for specific instructions

b)      Check whether SQL Browser service is running or not, if not or disabled, then enable and run it

c)      Reboot both nodes and try upgrades

d)      Check MSDTC, COM, Remote Registry, Task Scheduler services are configured properly or not. MSDTC should be a cluster resource group and running.

e)      Last one is, pause passive node, upgrade active node, then un-pause  passive node and try to upgrade passive with /passive switch else do a failover and do otherways

 

References for Building/Rebuilding MSDTC,

< 1.       How to rebuild or move a MSDTC installation to be used with a SQL failover cluster – http://support.microsoft.com/?id=294209

< 2.       http://www.winvistatips.com/msdtc-cluster-resource-not-t775222.html