Blog: Announcing Apache Pulsar 5.0.0-M1 (preview release)

[merlimat]

Draft — holding until the Apache Pulsar 5.0.0-M1 release vote passes. Publish date is set to 2026-06-23; adjust to the actual release date before merging.

What this is

A release announcement for Apache Pulsar 5.0.0-M1, the first milestone/preview of Pulsar 5.0 (currently under vote). The post:

• Frames M1 as a preview built for feedback — for testing on non-production clusters ahead of GA, not for production.
• Leads with Scalable Topics (Topics v5): why a topic should be a logical concept and not force a partition-count decision on developers, how the system adapts transparently from a single tens-of-GB/s firehose to millions of tiny topics, and the V5 client as a clean-slate API distilling 10+ years of lessons. Covers PIP-460/466/468/473/475/483.
• Covers Oxia as the recommended metadata store, the zero-downtime ZooKeeper→Oxia migration (PIP-454), metadata-store topic policies (PIP-469), and the etcd backend removal (PIP-462).
• Summarizes the other 5.0 changes: connector repo split (PIP-465), javax→jakarta (PIP-472), Gradle build (PIP-463), structured logging (PIP-467), networking (PIP-61/95).

Feature list verified against apache/master. Doc cross-links resolve on main (scalable-topics concepts, V5 client, and the migration guide are all merged).

Authors: Matteo Merli, Lari Hotari.

[lhotari]

A few review comments