Apache Cassandra 4.0 Released: New Features, Performance Boosts, and Enhanced Security

After a delay, Apache Cassandra 4.0 has officially been released. It is an open‑source distributed key‑value storage system originally developed by Facebook for storing extremely large data.

Apache Cassandra Vice President Nate McCall said that Cassandra 4.0 is a long journey and the most thoroughly tested Cassandra to date. The new version is faster, more scalable, and supports enterprise security features, enabling production at unprecedented scale in the cloud.

Cassandra v4.0 can easily handle unstructured data, writing thousands of times per second. After three years of development, v4.0 brings over 1,000 bug fixes, improvements, and new features, including:

Higher speed and scalability — streaming data during scaling operations can increase up to 5×, and read/write throughput up to 25%; providing a more resilient architecture, especially in cloud and Kubernetes deployments.

Improved consistency — keeping data replicas synchronized to optimize incremental repair for faster, more efficient operations and cross‑replica consistency.

Enhanced security and observability — audit logs track user access and activity with minimal impact on workload performance. New capture and replay support enables analysis of production workloads to help ensure compliance with SOX, PCI, GDPR, or other regulatory and security requirements.

New configuration settings — exposed system metrics and configuration settings give operators flexibility to easily access optimized deployment data.

Minimized latency — Garbage Collector pause times reduced to a few milliseconds without increasing latency as heap size grows.

Better compression — improved compression efficiency reduces unnecessary disk‑space pressure and improves read performance.

The official statement says that Cassandra 4.0 has already been hardened and tested by the community through Amazon, Apple, DataStax, Instaclustr, iland, Netflix and other users that typically run clusters of up to 1,000 nodes with hundreds of real use cases and schemas.

The Apache Cassandra community has deployed multiple testing and quality‑assurance (QA) projects and methods to deliver the most stable version to date. During testing and QA, the community generated realistic, reproducible workloads while effectively validating cluster state without pausing the workloads themselves.

Apache Cassandra contributor Scott Andreas said, “The contributors have worked hard to make Cassandra 4.0 the most stable release to date, ready for production‑critical cloud services. Cassandra 4.0 also brings new features such as faster host replacement, proactive data integrity assertions, incremental repair, and better compression. The project's investment in advanced verification tools means users can expect smooth upgrades. Once released, Cassandra 4.0 will also provide a stable foundation for future feature development and long‑term evolution of the database.”

In addition to Cassandra 4.0, the project announced a shift to an annual release cadence, with each release receiving three years of support.