Found SQL Server 2005 SP4 CU3 A/P failover cluster SQL services are stopping and starting several times in interval of 30mins to 1 hour. Following errors are found,   Application Log Errors: [sqsrvres] printODBCError: sqlstate = 08S01; native error = 0; message = [Microsoft][SQL Native Client]Communication link failure [sqsrvres] CheckQueryProcessorAlive: sqlexecdirect failed [sqsrvres] OnlineThread: QP is not online. [sqsrvres] printODBCError: sqlstate = 08S01; native error = 2746; message = [Microsoft][SQL Native Client]Communication link failure [sqsrvres] […]

In my case System admin accidently deleted SQL Server 2005 SQL Service resource from SQL cluster group (when trying to remove a disk from cluster) and re-added again but after re-adding SQL server failed to come up and following error noted in SQL Error log, ———– Error: 26054, Severity: 16, State: 1. Could not find any IP address that this SQL Server instance depends upon. Make sure that the cluster service is running, that the […]

Error in windows event logs: [sqsrvres] CheckQueryProcessorAlive: sqlexecdirect failed [sqsrvres] printODBCError: sqlstate = HYT00; native error = 0; message = [Microsoft][ODBC SQL Server Driver]Timeout expired  —————————- Suggestions from MSDN forum link: Reference link: http://social.msdn.microsoft.com/Forums/en-US/sqldisasterrecovery/thread/e5b8d938-e529-40f5-bdaa-601a8f6d7aca/ From the error it looks like there was issue with your network. Make sure you have a dedicated Heartbeat Network configured and that it is designated as such in Cluster Administrator. The public facing network can be configured for both Public […]

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,

http://blogs.msdn.com/b/pamitt/archive/2010/11/06/sql-server-clustering-best-practices.aspx Read about this in above article, few highlights to remember,

Source: http://social.msdn.microsoft.com/Forums/en-US/sqldatabasemirroring/thread/b6787cbc-e165-4730-9fba-7898af1716a6/ MSCS (Microsoft Cluster Services) is not a load-balancing product, it is simply a high-availability solution. Load balancing does not come in to play at all with clustering a Sql database…the term Active/Active seems to imply that this would be the case, which is why we typically try to refer to them as Multi-instance clusters now instead of the Active/Active label. Active/Active in the MSCS world basically means that you have 2 independent Sql […]