News

Apache Pulsar 3.0 is First Long-Term Support Release

• By John K. Waters
• May 24, 2023

The community behind the open-source Apache Pulsar all-in-one messaging and streaming platform has announced its first long-term support (LTS) release: Pulsar 3.0. This is the first of what the community promises is a new, faster release cadence.

"The previous release process has short maintenance cycles of approximately three to four months, while many users are still using old versions," according to a community blog post. "To keep up with new updates and features, they may be forced to perform upgrades within a short timeframe, for which they are not prepared in terms of available time and required efforts.... Therefore, the Pulsar community introduces LTS versions with feature releases between them."

With the new release cadence, the Pulsar community will be releasing LTS versions every 18 months, with bug fixes continuing for 24 months, and security vulnerability patches supported for 36 months. The new release cycle will follow a version of "semantic versioning," replacing the previous "major-minor-patch" cadence. For example: For example: 3.0.0 is the first LTS release. Version 3.0.1 will be a patch release, version 3.1.0 will be a feature release, as will version 3.2.0. The next LTS will be version 4.0.0.

Pulsar uses a system called Apache BookKeeper for persistent message storage. BookKeeper is a distributed write-ahead log (WAL) system that provides several crucial advantages for Pulsar: It enables Pulsar to utilize independent logs, called ledgers. Multiple ledgers can be created for topics over time. Messages can be consumed and acknowledged individually or consumed as streams with less than 10ms of latency. Pulsar's layered architecture allows for rapid scaling across hundreds of nodes, without data reshuffling.

More than140 contributors from the community submitted approximately 1,500 commits for feature enhancements and bug fixes in the 3.0 release. The list of enhancements includes: a new Pulsar broker load balancer, large-scale delayed message support, transaction buffer segmented snapshot optimization, blue-green cluster deployment support, and BookKeeper direct IO logic optimization. And with the 3.0 release, the community starts publishing Docker images with versions both for Intel x86-64 and Arm64 architectures.

Apache Pulsar has been recognized by the Apache Software Foundation as a Top 5 Project based on engagement.