Get SQL Server Windows Cluster Information
Problem
I have already identified that there is a SQL Server installed on a server.
Using PowerShell, I wanted to know if the server is using windows clustered
WITHOUT connecting the database instance.
This is an option that system administrators since they have admin rights
on the Operating System but don't have access to the SQL Server
instance.
I need to know the following:
1. I need to know if the server is clustered or not.
2. If the server is clustered, I need to know why type of clustering is
configured on the server.
SQL Server have 2 types of Windows
Clustering:
- Failover Cluster Instance
- Availability Group
You can also combine Failover Cluster
Instance with Availability Group.
I also wanted to know if this type of
configuration is configured on the server.
3. If the server is clustered, I also need to know if the server is active
or passive node
Solution
One of the requirements to be able to get windows clustering information is
to ensure that you have FailoverClusters PowerShell module installed on the
machine that you are using to run the PowerShell commands that are specified
below.
Let us step through the requirements:
1. How to check if the server is clustered or not?
Using HKEY_LOCAL_MACHINE check if there is a "Cluster" entry in the registry
PowerShell
Get-ItemProperty -Path Registry::HKEY_LOCAL_MACHINE\Cluster}
To check a server remotely you need to
use Invoke-Command
PowerShell
Invoke-Command -Computer $servername -ScriptBlock {Get-ItemProperty -Path Registry::HKEY_LOCAL_MACHINE\Cluster}
If no value is returned, the SQL Server
is standalone.
If the command returns a value, then SQL
Server is clustered using windows clustering.
2. How to check what type of clustering is configured on the server?
This is where the FailoverClusters module
will come-in handy.
We need to get/check the following:
a. Check WMIObject
MSCluster_ResourceGroup for root\mscluster namespace
b. Get-Cluster information of the
server
c. Get-ClusterResource information of the
server
Check root\mscluster namespace
PowerShell
Get-WMIObject -Class MSCluster_ResourceGroup -Namespace root\mscluster}
To check a server remotely you need to use
Invoke-Command
PowerShell
Invoke-Command -Computer $servername -ScriptBlock {Get-WMIObject -Class MSCluster_ResourceGroup -Namespace root\mscluster}
Get the cluster and cluster resource information of the server
PowerShell
Get-Cluster -Name $servername | Get-ClusterResource
If both root\mscluster namespace and
cluster resource does not return a value then the server is configured as
a "single node" cluster.
If both root\mscluster namespace and
cluster resource returns a value, we need to figure out what type of SQL
Server windows clustering is configured.
3. How to check if "Availability Group" is configured?
Using the cluster resource information,
check if there is a resource type called "SQL Server Availability
Group".
PowerShell
Get-Cluster -Name $servername | Get-ClusterResource | Where-Object ResourceType -eq 'SQL Server Availability Group'
If no results were returned then, the
server is configured with "Failover Cluster Instance".
If one result is returned, the server is
configured with "Availability Group/Listener".
If more than one result is returned, the
server is configured with multiple "Availability Group/Listener".
4. How to check if "FCI with Availability Group" is configured?
First you need to make sure that the
server is configured with "Availability Group".
Using the cluster resource information,
check if there is a resource type called "SQL Server Availability Group"
or resource type called "Network Name" and resource name that starts with
"SQL Network Name".
PowerShell
Get-Cluster -Name $servername | Get-ClusterResource | Where-Object { (($_.ResourceType -eq 'Network Name') -and ($_.Name -Like 'SQL Network Name *')) -or ($_.ResourceType -eq 'SQL Server Availability Group') }
If 2 different resource types are
returned, the server is configured with "FCI with Availability
Group".
NOTE: Ensure that you filter the
uniqueness of the returned resource type value.
5. How to check if the server is the active or passive node?
Using the cluster resource information,
get the OwnerNode for resource type called "SQL Server".
PowerShell
Get-Cluster -Name $servername | Get-ClusterResource | Where-Object ResourceType -eq 'SQL Server' | Select-Object OwnerNode
If the returned OwnerNode value is the
same as the $servername, then it is the "active" node, otherwise it is the
passive node.
Now you can combine all of the commands above to create a function that
will return the SQL Server Windows Cluster Information.
You can now download the Get-SQLServer-WindowsClusterInfo function from github.
