In the context of discussions of serverless databases, you may hear people talking about “the cluster.” Or you may hear references to an Aurora cluster, or a CockroachDB Serverless cluster. What does that actually mean?
A serverless database cluster is the collection of nodes that, all together, make up the database.
Serverless databases such as CockroachDB are also distributed databases. This means that, rather than living in a single place, the data in the database is split up and replicated across multiple “nodes” to ensure that it always remains available. “Cluster” refers to the collection of these nodes – all of the nodes that, together, make up your database.
(Of course, it’s all a bit more complicated than this makes it sound.This article is a great primer on the architecture of a serverless database.)