9.9. Summary
You should now have a better understanding of how Elasticsearch clusters are formed and how they’re made of multiple nodes, each containing a number of indices, which in turn are made up of a number of shards. Here are some of the other things we talked about in this chapter:
What happens when nodes are added to an Elasticsearch cluster
How master nodes are elected
Removing and decommissioning nodes
Using the _cat API to understand your cluster
Over-sharding and how it can be applied to plan for future growth of a cluster
How to use aliases and routing for cluster flexibility and scaling
In chapter 10 we’ll continue talking about scaling from the perspective of improving performance in your Elasticsearch cluster.