Since the first edition of this mostly covered Cassandra versions 2.1 and below, here is a list of features and improvements that have been made to Cassandra starting version 2.2 and beyond. This will give you a gist of how Cassandra has matured over the last year:
- JSON in CQL3: Cassandra 2.2 has support for inserting and selecting JSON data
- User-defined functions: These can be defined to apply a function to data stored in Cassandra
- User-defined aggregates: Using user-defined functions, custom aggregation functions can be stored in Cassandra
- Role-based access control: In addition to per-user access control, now roles can be defined for role-based access control
- Support for Windows 7, Windows 8, Windows 10, Windows Server 2008, and Windows Server 2012
- The storage engine has been refactored
- Materialized views: Materialized views have been added to handle server side denormalization, with consistency between base and view
- G1 garbage collector: The default garbage collector has been changed to G1 from CMS (concurrent mark and sweep), which has markedly increased performance for higher values of JVM heap sizes
- Hints are stored in files and replay has been improved
Note
Apart from these, there have been a plethora of operational improvements. You can take a look at them at https://docs.datastax.com/en/cassandra/3.x/cassandra/features.html.