Tencent Cloud Middleware

Nov 17, 2021 · Operations

How Apache Pulsar Guarantees No Duplicate Delivery: A Deep Dive into Ack Modes

This article explains why message acknowledgment is crucial in Apache Pulsar, describes the four ack modes, shows which subscription types support each mode, and details the internal implementation, batching, negative ack handling, and unacknowledged‑message processing for reliable broker‑consumer communication.