Tribe node

The tribes feature allows a tribe node to act as a federated client across multiple clusters.

The tribe node works by retrieving the cluster state from all connected clusters and merging them into a global cluster state. With this information at hand, it is able to perform read and write operations against the nodes in all clusters as if they were local.

The elasticsearch.yml config file for a tribe node just needs to list the clusters that should be joined, for instance:

tribe:
    t1: 
        cluster.name:   cluster_one
    t2: 
        cluster.name:   cluster_two

The example above configures connections to two clusters, name t1 and t2 respectively. The tribe node will create a node client to connect each cluster using multicast discovery by default. Any other settings for the connection can be configured under tribe.{name}, just like the cluster.name in the example.

The merged global cluster state means that almost all operations work in the same way as a single cluster: distributed search, suggest, percolation, indexing, etc.

However, there are a few exceptions:

The tribe node can be configured to block all write operations and all metadata operations with:

tribe:
    blocks:
        write:    true
        metadata: true

The tribe node can also configure blocks on indices explicitly:

tribe:
    blocks:
        indices.write: hk*,ldn*

When there is a conflict and multiple clusters hold the same index, by default the tribe node will pick one of them. This can be configured using the tribe.on_conflict setting. It defaults to any, but can be set to drop (drop indices that have a conflict), or prefer_[tribeName] to prefer the index from a specific tribe.