Cursor Management

High Availability Architecture

Dec 24, 2021 · Backend Development

Understanding Broker‑Side Message Acknowledgment and Cursor Management in Apache Pulsar

This article explains how Apache Pulsar brokers track consumer acknowledgment using cursors, describes persistent and non‑persistent subscription differences, details cursor metadata stored in ZooKeeper and BookKeeper, and outlines optimizations for handling message gaps, including RangeSet improvements and a new LRU‑based storage design.