If I am implementing a SPLUNK HA architecture with indexed data cloned to a secondary mirrored indexer cluster(at another data centre)..I have to double my Enterprise license volume or obtain a special HA License.
As an alternative to that approach, If I employ a SAN replication based approach rather than the data cloning approach described above ,do I have to plan for any additional licensing ?
The license is charged by how much data you index not how many times you copy/move the indexed data. If you have the ability to write to a SAN and set up clustered indexers you can also get to a HA architecture. Not everyone has this ability and sometimes it's simpler to index in two locations.
Must agree. Unless you're paying for it already for another application, the cost of infrastructure for SAN replication is likely substantially higher than what you could negotiate with Splunk to double your license size. Typically, you are also limited by distance (technically latency) across the SAN extension.