The term redundancy can mean different things, depending on your concern. Splunk has features to help with some of these concerns, but not others. Starting with Splunk version 5, Splunk added data replication features that can eliminate most of these concerns. Let's take a quick look at the topic now.
When setting up a Splunk indexer cluster, you stipulate the number of copies of data that you want the cluster to maintain. Peer nodes store incoming data in buckets, and the cluster maintains multiple copies of each bucket. The cluster stores each bucket copy on a separate peer node. The number of copies of each bucket (that the cluster maintains) is known as the Splunk replication factor.
Let's try to explain this concept (of the replication factor) with a highly simplified example.
Keep in mind that a cluster (of indexes) can tolerate a failure of 1 less than your total replication factor. So, if you have configured 3 peer indexes, you have a replication...