How does Cassandra support multi-tenancy?

Cassandra supports multi-tenancy primarily by allowing different keyspaces for different tenants. A keyspace in Cassandra serves as a namespace that defines how data is stored and replicated across the cluster. Each tenant can have its own keyspace, which means that data can be logically separated while still being stored in the same physical cluster. This separation helps ensure that tenants do not interfere with each other’s data, allowing for individual configuration of replication factors, consistency levels, and more.

By utilizing different keyspaces, Cassandra allows different tenants to operate independently, making it easier to manage their specific data retention, performance requirements, and access controls. This is a practical and effective approach to ensuring data integrity and security for each tenant while maximizing resource usage in the same environment.

The other approaches such as creating multiple replicas of data for each tenant or using different clusters may not be as efficient for resource management and can incur higher operational costs. Enforcing strict access controls is certainly important for security, but it is primarily a mechanism of data access rather than a foundational method of support for multi-tenancy. The flexibility offered by keyspaces is specifically designed to cater to various tenants within a single Cassandra environment.