SQL Server clustering is a widely used technique for creating a highly available configuration. It has been used for many years and is considered a reliable solution. However, there are certain nuances and rules that need to be understood, especially for junior DBAs.
One of the questions I recently received from a reader was about the significance of the various rules that are validated when configuring a cluster in SQL Server 2008 edition. Surprisingly, there was not much information available on this topic. In this article, I will outline the 11 rules that are part of the Cluster Global Rules in SQL Server.
It is important to note that these rules are validated only on the node where the setup is being performed. Some of these rules are critical, while others are optional.
1. Fusion Active Template Library (ATL)
This rule checks if a computer restart is required due to a broken fusion ATL. A pending restart can cause SQL Server Setup to fail.
2. Unsupported SQL Server Products
This rule checks whether SQL Server 7.0 or SQL Server 7.0 OLAP Services are installed. SQL Server 2008 is not supported with SQL Server 7.0.
3. Not Clustered or the Cluster Service is Up and Online
This rule verifies that the computer is not clustered or, if it is clustered, that the cluster service is online.
4. Windows Management Instrumentation (WMI) Services (“Node Name”) – Local Node
This rule checks whether the WMI service is running on the cluster because Setup is dependent on this service.
5. Cluster Remote Access (“Node Name”) – Local Node
This rule checks whether the user running the Setup operation has remote access on the remote cluster node(s).
6. Remote Registry Service (“Node Name”) – Remote Node
This rule checks whether the Remote Registry service is enabled.
7. Domain Controller
This rule checks if the computer is a Windows Domain controller.
8. Microsoft .NET Application Security
This rule verifies that the computer is connected to the Internet. When a Microsoft .NET application like Microsoft Management Studio starts, there may be a slight delay while the .NET security check validates a certificate.
9. Network Binding Order
This rule checks if the computer domain server is on the network that is bound to the top of the network order.
10. Windows Firewall
This rule checks whether the Windows Firewall is enabled.
11. DNS Settings (“Node Name”) – Local Node
This rule checks if the DNS search list on the computer (“Node Name”) is consistent with the other nodes of a cluster.
It is worth mentioning that the number of checks may vary depending on the version of SQL Server being used.
I hope this article has helped demystify some of the basics of SQL Server Cluster Global Rules. It is important for DBAs, especially junior ones, to understand these rules to ensure a successful cluster configuration.
Do you regularly review the list of rules when setting up a cluster? Let me know your thoughts in the comments below!