Enterprise Integration Patterns


Enterprise Integration Patterns is a book by Gregor Hohpe and Bobby Woolf which describes 65 pattern |pattern]s for the use of enterprise application integration and message-oriented middleware in the form of a pattern language.

The integration (messaging) pattern language

The pattern language presented in the book consists of 65 patterns structured into 9 categories, which largely follow the flow of a message from one system to the next through channels, routing, and transformations. The book includes an icon-based pattern language, sometimes nicknamed "GregorGrams" after one of the authors. Excerpts from the book are available on the supporting website.

Integration styles and types

The book distinguishes four top-level alternatives for integration:
  1. File Transfer
  2. Shared Database
  3. Remote Procedure Invocation
  4. Messaging
The following integration types are introduced:
  • Information Portal
  • Data Replication
  • Shared Business Function
  • Service Oriented Architecture
  • Distributed Business Process
  • Business-to-Business Integration
  • Tightly Coupled Interaction vs. Loosely Coupled Interaction

    Messaging

  • Message Channel
  • Message
  • Pipes and Filters
  • Message Router
  • Message Translator
  • Message Endpoint

    Message Channel

  • Point-to-Point Channel
  • Publish-Subscribe Channel
  • Datatype Channel
  • Invalid Message Channel
  • Dead Letter Channel
  • Guaranteed Delivery
  • Channel Adapter
  • Messaging Bridge
  • Message Bus

    Message Construction

  • Command Message
  • Document Message
  • Event Message
  • Request-Reply
  • Return Address
  • Correlation Identifier
  • Message Sequence
  • Message Expiration
  • Format Indicator

    Message Router

  • Content-Based Router
  • Message Filter
  • Dynamic Router
  • Recipient List
  • Splitter
  • Aggregator
  • Resequencer
  • Composed Message Processor
  • Scatter-Gather
  • Routing Slip
  • Process Manager
  • Message Broker

    Message Transformation

  • Envelope Wrapper
  • Content Enricher
  • Content Filter
  • Claim Check
  • Normalizer
  • Canonical Data Model

    Message Endpoint

  • Messaging Gateway
  • Messaging Mapper
  • Transactional Client
  • Polling Consumer
  • Event-Driven Consumer
  • Competing Consumers
  • Message Dispatcher
  • Selective Consumer
  • Durable Subscriber
  • Idempotent Receiver
  • Service Activator

    System Management

  • Control Bus
  • Detour
  • Wire Tap
  • Message History
  • Message Store
  • Smart Proxy
  • Test Message
  • Channel Purger
The pattern language continues to be relevant as of today, for instance in cloud application development and integration, and in the internet of things. In 2015, the two book authors reunited—for the first time since the publication of the book—for a retrospective and in IEEE Software.

Implementation

Enterprise Integration Patterns are implemented in many open source integration solutions. Notable implementations include Spring Integration, Apache Camel, Red Hat Fuse, Mule ESB and Guaraná DSL.