vsamantha35 (8/5/2014)
Thanks Perry. Again, what is split brain? I have read that whenever private/heartbeat network fails, split brain occurs?
It happens less and less with the latest versions of Windows Server due to enhancements within the WSFC subsystem. The split brain scenario occurs when subsets of the cluster nodes are separated or partitioned by a network outage, say between sites. Both sets of nodes may then attempt to own the same shared resources causing corruption in extreme cases.
vsamantha35 (8/5/2014)
Consider I have a 3 node cluster (N1,N2,N3) and private network completely is down on N1 and cannot communicate to other nodes.and private network is not set for "All communications", so I would a expect a failover from N1 to next possible owner. It could be N2 or N3 depending on install order.
1) Now, my doubt is when does the split brain happen or when can a split brain situation occurs?
2) What happens if a split brain occur?
3) What will happen to a cluster in that scenario? Is there any auto healing functionality to come out of that situation?
In Windows 2008 onwards you do not need a dedicated private\heartbeat network. You do need multiple redundant networks but they’re not strictly reserved for heartbeat communications. The cluster nodes each have a virtual cluster network adapter that binds itself to an available cluster network that is set to allow cluster communications. The public network has this by default.
A cluster network has 3 possible settings
The split brain occurs when all network paths are broken and subsets of nodes cannot communicate with a partitioned subset. Again, a failure of a heartbeat network only does not initiate a failover as cluster communication will continue over the next available network enabled for cluster communication.
Build yourself a virtual test cluster and test this yourself easily.
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