Chapter 2. Data Distribution

Cassandra's peer-to-peer architecture and scalability characteristics are directly tied to its data placement scheme. Cassandra employs a distributed hash table data structure that allows data to be stored and retrieved by a key quickly and efficiently. Consistent hashing is the core of this strategy as it enables all nodes to understand where data exists in the cluster without complicated coordination mechanisms.

In this chapter, we'll cover the following topics:

• The fundamentals of distributed hash tables
• Cassandra's consistent hashing mechanism
• Token assignment, both manual and using virtual nodes (vnodes)
• The implications of Cassandra's partitioner implementations
• Formation of hotspots in the cluster

By the time you finish this chapter, you should have a deep understanding of these concepts. Let's begin with some basics about hash tables in general, and then we can delve deeper into Cassandra's distributed hash table implementation...