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Message Queue for RocketMQ

Overview

Related concepts

Queue

In Message Queue for RocketMQ, messages are stored in one or more queues within each topic.

Offset

MaxOffset: The total number of messages currently stored in a partition.

MinOffset: The starting position of a partition.

ConsumerOffset: The number of messages that have been consumed sequentially from a partition.

Scheduled message

After a producer sends a scheduled message to the Message Queue for RocketMQ server, consumers cannot immediately consume the message. Rather, it is delivered to consumers only at the specified time.

Delayed message

After a producer sends a delayed message to the Message Queue for RocketMQ server, consumers cannot immediately consume the message. Rather, it is delivered to consumers only after the specified period has elapsed.

tip

Message Queue for RocketMQ allows you to customize delay times in milliseconds. The maximum delay duration is either three days or three times the message retention period, whichever is shorter.

Transactional message

Transactional messages can be used to achieve eventual consistency in distributed transactions.

Ordered message

Messages are consumed in the same order that they are published, following the first-in, first-out (FIFO) principle. Both global and partitioned ordered consumption are supported.

Global ordered consumption: Messages are published and consumed in the order they are produced.

Partitioned ordered consumption: Messages within a partition are published and consumed in the order they are sent to that partition.

Dead-letter message

Message Queue for RocketMQ automatically retries messages that have not been successfully consumed. If consumption still fails after the maximum number of retry attempts is reached, the message is considered undeliverable under normal conditions and is classified as a dead-letter message.

Dead-letter queue

When a consumer subscribes to a topic, Message Queue for RocketMQ automatically creates a dead-letter queue to store dead-letter messages.

Cluster consumption

Messages from the same topic are processed by only one consumer within the cluster. Each consumer consumes only a subset of messages from the topic, and each message is consumed only once.

Broadcast consumption

Messages from the same topic are consumed once by all subscribed consumers. In other words, a consumer consumes all messages in the topic, and each message is consumed multiple times.

Last updated: 2026.08.26 11:17:41