Federated search
Sometimes, having data in a single cluster is not enough. Imagine a situation where you have multiple locations where you need to index and search your data-for example, local company divisions that have their own clusters for their own data. The main center of your company would also like to search the data-not in each location but all at once. Of course, in your search application, you can connect to all these clusters and merge the results manually, but from Elasticsearch 1.0, it is also possible to use the so-called tribe node that works as a federated Elasticsearch client and can provide access to more than a single Elasticsearch cluster. What the tribe node does, is fetch all the cluster states from the connected clusters and merge these states into one global cluster state available on the tribe node. In this section, we will take a look at tribe nodes and how to configure and use them.
The test clusters
For the purpose of showing you how tribe nodes work, we will create...