Integration Patterns in BizTalk Server 2004

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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

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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

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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

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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

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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

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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

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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

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Normalizer
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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

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Normalizer - Example

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

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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

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Publish-Subscribe Channel
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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

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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

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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

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Wire Tap
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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.

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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

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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

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Test Message
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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

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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

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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

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Enterprise Integration Patterns in BizTalk
Further Reading

• Enterprise Integration Patterns Gregor Hohpe
• www.eaipatterns.com
• 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