Search This Blog

Failover Clustering

Failover Clustering

SQL Server 2005

  • Multi-instance clusters – each instance requires its own resources
  • Multi-node – more nodes per configuration, active/active, active/passive, N+1 – plann carefully
  • Analysis Services clusterable
  • See http://msdn.microsoft.com/en-us/library/ms143511.aspx
  • Integration Services – Can be clustered. Discussion - Where to store the packages?
  • Reporting services not clusterable  - Consider using network load balancing instead
  • Can rename a clustered instance
  • Majority Node Set
  • See http://suppot.microsoft.com/kb/838612

SQL Server 2008

  • Cluster Validation tool
  • Support for up to 16 nodes
  • New quorum model: File Server Witness, Node Majority
  • Edit subnet mask, DHCP, IPv6
  • GPT disks, support for >2TB partitions
  • Improved cluster setup, error reporting
  • Rolling upgrades, one node at a time
  • See http://msdn.microsoft.com/en-us/library/ms189910.aspx

Failure Detection

  • Node failure
  • Resource failure detected
  • LooksAlive – SQL Server status – default every 5 seconds
  • IsAlive – SELECT @@SERVERNAME – default every 60 seconds
  • See http://blogs.technet.com/rob/archive/2008/05/07/failover-clustering.aspx 
  • Upon failover – new instance comes up on other node
  • SQL Server 2005+ – Enterprise Edition – service available after Redo phase completes
  • Failback – Available using use preferred owner

Troubleshooting

  • Verify failover
  • Careful – Post-install tasks like manual IP ports, additional disks – Check resources
  • Logs: Windows Event Logs, Cluster log, SQL Server Setup log
  • Books Online: Failover Cluster Troubleshooting
  • See http://msdn.microsoft.com/en-us/library/ms189117.aspx

Clustering Details

  • Client design: To the app, failover process looks like server taking a long while to respond. Consider adding retry logic.
  • Planning: Verify hardware solution, run validation, plan security for service accounts, plan SQL Tools location
  • Migration: Verify OS settings (CSP, Kerberos), MSDTC, pre-requisites
  • Heartbeat: TCP/IP configuration, binding order, remove NETBIOS
  • Virtualization: Check support policy (KB below), guest failover not supported, SVVP
  • See http://support.microsoft.com/KB/956893
  • See http://support.microsoft.com/KB/956893
  • Adding a node: Set SQL setup, select add cluster node
  • Removing a node: Set SQL setup, select remove cluster node
  • SQL Server setup can be fully scripted, including cluster install, add cluster node, etc.
  • Example: SETUP.EXE /q /ACTION=InstallFailoverCluster /INSTANCENAME=...
  • Example: SETUP.EXE /q /ACTION=AddNode /INSTANCENAME=...
  • See http://msdn.microsoft.com/en-us/library/ms144259.aspx 
  • Careful – SQL Server 2008 cluster setup is now run one node at a time
  • Cluster log: Use CLUSTER.EXE command line to obtain text log
  • See http://blogs.msdn.com/clustering/archive/2008/09/24/8962934.aspx

Combining with other features

Clustering vs. Mirroring


 

1 comment:

Radley Co Tad said...

This is an amazing blog,it gives very helpful messages to us.Besides that Wisen has established as Best Dot Net Training in Chennai. or learn thru ASP.NET Online Training . Nowadays Dot Net has tons of job opportunities on various vertical industry.