Still looking for clarity on this question. If the search head cluster is considered part of the index cluster, then must I also plan on upgrading the master node to 6.4? This sentence seems to indicate this, but it was not mentioned in the above answer. "...the master node must run at the same or a higher level than both search heads and peer nodes. So, for example, you can have a 6.3 master node with a 6.3 search head and a set of 6.2 peer nodes. You cannot, however, have a 6.2 master node with a 6.3 search head and a set of 6.2 peer nodes. " ... View more

Thanks Steve G., Please also confirm that if I build a v6.4 search head cluster, than I must also upgrade the cluster master to v6.4 as well. As the documentation appears to state this as a requirement. "...the master node must run at the same or a higher level than both search heads and peer nodes. So, for example, you can have a 6.3 master node with a 6.3 search head and a set of 6.2 peer nodes. You cannot, however, have a 6.2 master node with a 6.3 search head and a set of 6.2 peer nodes. " ... View more