SQL Server Performance

can SQL server failover to second node when SQL server hangs up but windows is up?

Discussion in 'SQL Server 2005 Clustering' started by To_DBA, Jan 9, 2009.

  1. To_DBA New Member

    Hi All
    does the SQL cluster has this function: SQL server can automatically failover to second node when it hangs up (App can't access it) but the windows server is still up and running?
    thanks in advance.
  2. gurucb New Member

    Yes it can. For SQL Server there is a SQLRES.dll that does ISAlive and LooksAlive Test.
    IsAlive test connects to SQL Server and AFAIK, runs select @@Version query. and by default it runs every 30 seconds. And if not able to SQL Server (due to hang) it would fail over SQL Server to the other node.
    But if you are running SQL Server 2005 on Windows 2003, check if the SQL Resource Proprety "Failover Group" is set as by default this is not set.
    Prior to all these there is a need to understand why SQL was hung in first place were there any new dump files generated.
  3. To_DBA New Member

    thank you very much for this usefull infomation.
    by the way, could you please let me know if i can set this property in SQL 2000 clustered? we have one SQL 2000 clustered too.
    thanks again.
  4. gurucb New Member

    Yes this is set by default in sql server 2000.
  5. GopalMynam New Member

    Hi,
    Can you detail how to check this
    "But if you are running SQL Server 2005 on Windows 2003, check if the SQL Resource Proprety "Failover Group" is set as by default this is not set. "
    Thanks,
    Gopal
  6. satya Moderator

    Use the CLUADMIN tool to set such dependancies.
  7. satya Moderator

    It is possible but mostly the SQL resources are dependant on windows resources too, so in this case you may have connectivity lag when SQL is up on other node.

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