c# - get hostname of failover cluster role in .Net

Question

I have a Windows service which is supposed to run in a (Windows Server 2012 R2) failover cluster as a generic service in a dedicated role, that is, there is a hostname and IP address configured for this service in the failover cluster manager. (I think 'role' used to be called 'group' in earlier Windows server releases).

One requirement is that the service has to know/provide the hostname of the role it is running in. System.Net.Dns.GetHostName() returns the name of the physical server on which the service is currently active, but what is needed is the configured hostname of the role.

I've searched both in the dns APi direction and the MS documentation for the System.ServiceProcesses namespace, but was not able to figure this out from these resources.

Is there a .Net API which is able to retrieve this, or is that the wrong approach altogether? (I.e. should this information be written into a configuration database during installation and retrieved from there).

Answer 1

There is a .NET API for Failover Clustering. Please refer to it here -

• https://msdn.microsoft.com/en-us/library/aa372876(v=vs.85).aspx

As for your qeustion, I believe every Role has an OwnerNode property and this WMI Class should help you.

MSCluster_Node class

[Dynamic, Provider ("MS_CLUSTER_PROVIDER"), UUID ("{C306EBED-0654-4360-AA70-DE912C5FC364}")]class MSCluster_Node : CIM_UnitaryComputerSystem
{   
 string             Roles[];
}

https://msdn.microsoft.com/en-us/library/aa371446(v=vs.85).aspx

If you drill down to the methods there is also a -

• ExecuteNodeControl method which even has a CLUSCTL_NODE_GET_ID

https://msdn.microsoft.com/en-us/library/cc512216(v=vs.85).aspx

If the above doesn't help you, you can also try the reference below.

The MSCluster_ResourceToPossibleOwner class is a dynamic association WMI class that represents a list of the resources and their possible owner nodes.

• https://msdn.microsoft.com/en-us/library/aa371478(v=vs.85).aspx

Hope this helps, I'm pretty new to doing stuff with Failover Clustering and C#. I hope I can learn from this post as well.