Chapter 4. Data Centers

One of Cassandra's most compelling high availability features is its support for multiple data centers. In fact, this feature gives it the capability to scale reliably with a level of ease that few other data stores can match.

In this chapter, we'll explore Cassandra's data center support, covering the following topics:

• Use cases for multiple data centers
• Using a separate data center for online analytics
• Replication across data centers
• An in-depth look at configuring snitches
• Multiregion EC2 implementations
• Consistency levels for multiple data centers

Database administrators have struggled for many years to reliably replicate data across multiple geographies—a task that is made especially difficult when the system attempts to maintain ACID guarantees. The best we could typically hope for was to keep a relatively recent backup for failover purposes.

Distributed database designs have made this easier, but many of these still require complex configurations...