Integration Patterns in BizTalk Server 2004 Integration Patterns Explained What are integration patterns? What patterns does BizTalk Server 2004 provide out of the box? Implementing integration patterns in BizTalk Server 2004 Pattern Implementations in BizTalk Server 2004 Normalizer Publish subscribe channel Wire tap Test message

What are Integration Patterns? Patterns are accepted solutions to recurring problems within a given context. They are abstract enough to apply to most integration technologies, but specific enough to provide hands-on guidance to designers and architects. Patterns also provide a vocabulary for developers to efficiently describe their solution. Gregor Hohpe

What Integration Pattern Implementations Does BizTalk Provide out of the Box? Publish-Subscribe Channel How can the sender broadcast an event to all interested receivers? The BizTalk message engine is built on a publish-subscribe architecture All messaging within BizTalk Server is publish subscribe Guaranteed Delivery How can the sender make sure that a message will be delivered, even if the messaging system fails? Messages are persisted to a SQL Server Database (the message box database) BizTalk can be configured to use retries and secondary transports when sending messages

What Integration Pattern Implementations Does BizTalk Provide out of the Box? Channel Adapter How can you connect an application to the messaging system so that it can send and receive messages? BizTalk 2004 ships with seven adapters out of the box. File, FTP, SQL Server, HTTP, SOAP, MSMQ/T, SMTP

What Integration Pattern Implementations Does BizTalk Provide out of the Box? Polling Consumer How can an application consume a message when the application is ready? The FTP Adapter can poll an FTP server to receive any files that are added The SQL Adapter can poll a database table to trigger messages when data is added or modified Event Driven Consumer How can an application automatically consume messages as they become available? The File Adapter is event driven when using Windows NTFS folders The SOAP and HTTP Adapters are event driven

Implementing Integration Patterns in BizTalk Server 2004 Use Integration Patterns to Develop BizTalk Solutions The pattern language is used across multiple integration platforms Many BizTalk Server projects use integration patterns BizTalk pattern implementation resources are widely available (MSDN, White Papers, Blogs, Books, BizTalk Deep Dive Course) Easy to Implement Splitter – Messages can easily be split as BizTalk receives them, and processed separately Hard to Implement Aggregator – Combining multiple messages into a single message is a fairly complex task

Normalizer Problem How can an integration hub communicate with multiple business partners that all send messages in a different format? Solution Use a normailzed representation of data objects within the hub Partner specific representations of data objects are transformed at system boundaries Benefits Partners can be added to the hub without modifying internal business process Partners can modify their data format or message schema without affecting internal business processes

Normalizer

Normalizer - Implementation BizTalk Implementation Message maps are created to transform partner specific schemas to and from internal schemas The partner specific maps are placed within the send and receive ports of the messaging solution

Normalizer - Example The BizTalk Mapper is used to create a map that transforms the partner specific message format to the normalized data format

Publish-Subscribe Channel Problem How can messages transmitted by the hub be routed effectively to the relevant business partners? Solution Message subscriptions are created for each partner to subscribe to relevant messages based on a filter criteria The hub sets the properties used in the subscriptions, then publishes the message When a message is published, one copy of the message is created for each subscriber Benefits The message routing is independent of the business process Subscriptions can be added, modified, and removed easily

Publish-Subscribe Channel

Publish-Subscribe Channel - Implementation Implementation “Promoted Properties” are created in the schema to make the routing properties available to the messaging engine The orchestration sets the promoted properties in the message to appropriate values for routing, and publishes the message. Send ports are created with filter based subscriptions using the promoted properties

Publish-Subscribe Channel - Example Schema properties are promoted and available for message subscriptions Send ports are created with filter based subscriptions using the promoted properties

Wire Tap Problem How can the message flow at a specific point in the messaging system be monitored? Solution Subscription based send ports are created with filters for messages at a specific point in messaging system These “Wire Tap” send ports can be started when required Benefits Provides a quick solution to diagnose problems in messaging system

Wire Tap

Wire Tap - Implementation Implementation Create a Send Port with a filter that subscribes to a specific message type Create a Send Port with a filter that subscribes to a point in the system, such as a receive port. Message Tracing BizTalk Server 2004 also allows Message Tracking to be configured to provide similar functionality to a “Wire Tap” port.

Wire Tap - Example A wire tap is created using a send port which subscribes to all messages passing through s specific point in the system

Test Message Problem How can a message hub be tested in a production environment without affecting the systems of business partners using the hub? Solution A message is sent into the hub, with a flag set to identify it as a test message The message hub will process the message A wire tap is created to route test messages to a different location Benefits The message hub can easily be tested in a production environment Tests can be performed manually or as part of an automated test program

Test Message

Test Message - Implementation Implementation The message schema is modified to include a “Test Message” flag in the message header The subscriptions of the send ports that send messages to the partners are modified so as not to subscribe to test messages A wire tap send port is created to subscribe to messages with “Test Message” flag set, and send them to a location for verification Test data generators and verifiers can be created to implement automated testing

Test Message - Example The TestMessage element added to the schema The element is promoted to make it available for use in message subscriptions A Wire-Tap is created to subscribe to test messages after processing

Enterprise Integration Patterns in BizTalk Summary Integration patterns form a common language that can be used in integration projects These patterns are widely used within BizTalk and other integration platforms BizTalk Server 2004 provides a number of pattern implementations out of the box Many other patterns can be implemented easily within BizTalk Patterns to aggregate, or resequence messages can be complex to implement, but sample implementations are available

Enterprise Integration Patterns in BizTalk – Further Reading Enterprise Integration Patterns – Gregor Hohpe BizTalk Server 2004 Unleashed – Scott Woodgate MSDN – BizTalk patterns whitepapers msdn.microsoft.com/biztalk The Bloggers Guide to BizTalk – Alan Smith + BizTalk blogging community geekswithblogs.com/asmith