Enterprise integration patterns (EIP) is a catalog of design patterns for developing systems to integrate new and existing software in a business environment which is a book by Gregor Hohpe and Bobby Woolf. It describes 65 patterns structured into 9 categories for the use of enterprise application integration and message-oriented middleware in the form of patterns and includes an icon-based pattern language sometimes called GregorGrams.
Notation of Enterprise Integration Patterns
Message Routing
Aggregator
How do we combine the results of individual, but related messages so that they can be processed as a whole?
Composed Message Processor
How can you maintain the overall message flow when processing a message consisting of multiple elements, each of which may require different processing?
Content-Based Router
How do we handle a situation where the implementation of a single logical function (e.g., inventory check) is spread across multiple physical systems?
Dynamic Router
How can you avoid the dependency of the router on all possible destinations while maintaining its efficiency?
Message Broker
How can you decouple the destination of a message from the sender and maintain central control over the flow of messages?
Message Filter
How can a component avoid receiving uninteresting messages?
Process Manager
How do we route a message through multiple processing steps when the required steps may not be known at design-time and may not be sequential?
Recipient List
How do we route a message to a list of (static or dynamically) specified recipients?
Resequencer
How can we get a stream of related but out-of-sequence messages back into the correct order?
Routing Slip
How do we route a message consecutively through a series of processing steps when the sequence of steps is not known at design-time and may vary for each message?
Splitter
How can we process a message if it contains multiple elements, each of which may have to be processed differently?
Message Transformation
Claim Check
How can we reduce the data volume of the message sent across the system without sacrificing information content?
Content Enricher
How do we communicate with another system if the message originator does not have all the required data items available?
Content Filter
How do you simplify dealing with a large message, when you are interested only in a few data items?
Normalizer
How do you process messages that are semantically equivalent, but arrive in a different format?
Messaging Channels
Point to Point Channel
How can the caller be sure that exactly one receiver will receive the document or perform the call?
Publish-Subscribe Channel
How can the sender broadcast an event to all interested receivers?
Channel Adapter
How can you connect an application to the messaging system so that it can send and receive messages?
Dead Letter Channel
What will the messaging system do with a message it cannot deliver?
Messaging Bridge
How can multiple messaging systems be connected so that messages available on one are also available on the others??
Message Bus
What is an architecture that enables separate applications to work together, but in a de-coupled fashion such that applications can be easily added or removed without affecting the others?
Messaging Endpoints
Competing Consumers
How can a messaging client process multiple messages concurrently?
Durable Subscriber
How can a subscriber avoid missing messages while it’s not listening to them?
Event-Driven Consumer
How can an application automatically consume messages as they become available?
Message Dispatcher
How can multiple consumers on a single channel coordinate their message processing?
Messaging Gateway
How do you encapsulate access to the messaging system from the rest of the application?
Polling Consumer
How can an application consume a message when the application is ready?
Selective Consumer
How can a message consumer select which messages it wishes to receive?
Service Activator
How can an application design a service to be invoked both via various messaging technologies and via non-messaging techniques?
Transactional Client
How can a client control its transactions with the messaging system?
Messaging Systems
Message Router
How can you decouple individual processing steps so that messages can be passed to different filters depending on a set of conditions?
Message Channel
How does one application communicate with another using messaging?
Message Endpoint
How does an application connect to a messaging channel to send and receive messages?
Message
How can two applications connect by a message channel exchange a piece of information?
Message Translator
How can systems using different data formats communicate with each other using messaging?
System Management
Control Bus
How can we effectively administer a messaging system that is distributed across multiple platforms and a wide geographic area?
Detour
How can you route a message through intermediate steps to perform validation, testing or debugging functions?
WireTap
How do you inspect messages that travel on a point-to-point channel?
Message Construction
Event Message
How can messaging be used to transmit events from one application to another?
Message Expiration
How can a sender indicate when a message should be considered stale and thus shouldn’t be processed?
Return Address
How does a replier know where to send the reply?