Enterprise Integration Patterns
Messaging Patterns
Messaging Patterns
ResequencerResequencerMessaging Patterns » Message Routing

A Message Router can route messages from one channel to different channels based on message content or other criteria. Because individual messages may follow different routes, some messages are likely to pass through the processing steps sooner than others, resulting in the messages getting out of order. However, some subsequent processing steps do require in-sequence processing of messages, for example to maintain referential integrity.

How can we get a stream of related but out-of-sequence messages back into the correct order?

Use a stateful filter, a Resequencer, to collect and re-order messages so that they can be published to the output channel in a specified order.

The Resequencer can receive a stream of messages that may not arrive in order. The Resequencer contains in internal buffer to store out-of-sequence messages until a complete sequence is obtained. The in-sequence messages are then published to the output channel. It is important that the output channel is order-preserving so messages are guaranteed to arrive in order at the next component. Like most other routers, a Resequencer usually does not modify the message contents.

... Read the entire pattern in the book Enterprise Integration Patterns

Related patterns:

Aggregator, Competing Consumers, Message Router, Message Sequence, Pipes and Filters, Splitter, Test Message

Creative Commons Attribution License

You can reuse the following elements under the Creative Commons Attribution license: pattern icon, pattern name, problem and solution statements (in bold), and the sketch. Other portions are protected by copyright.

Enterprise Integration Patterns book cover

Enterprise Integration Patterns
The classic, as relevant as ever. Over 90,000 copies sold.

Software Architect Elevator book cover

The Software Architect Elevator
Learn how architects can play a critical role in IT transformation by applying their technical, communication, and organizational skills.

Cloud Strategy book cover

Cloud Strategy
Fill the large gap between high-level goals and product details by understanding decision trade-offs.