The document discusses various integration solution patterns including enterprise integration patterns (EIPs), implementation of EIPs using WSO2 Enterprise Service Bus (ESB), and high-level integration patterns like API gateway, service broker, and dual channeling. It describes how functional components of WSO2 ESB like mediators and sequences can be used to implement EIPs. Overall it provides an overview of best practices, approaches and strategies for designing integration solutions using patterns.

1. Integration Solution Patterns
© WSO2 2013. Not for redistribution. Commercial in Confidence.
May 2013
Nadeesha Gamage
Dakshitha Ratnayake

2. About WSO2
• Providing the only complete open source componentized cloud platform
• Dedicated to removing all the stumbling blocks to enterprise agility
• Enabling you to focus on business logic and business value
• Recognized by leading analyst firms as visionaries and leaders
• Gartner cites WSO2 as visionaries in all 3 categories of application
infrastructure
• Forrester places WSO2 in top 2 for API Management
• Global corporation with offices in USA, UK & Sri Lanka
• 200+ employees and growing
• Business model of selling comprehensive support & maintenance for our products

3. 150+ globally positioned support customers

4. Integration
Image Source -
http://blog.bootstraptoday.com/2013/01/03/considering-saas-3-tips-for-your-data-integration-strategy/

5. Integration – Why?
• Business applications rarely live in isolation.
• Users expect instant access to all business functions an
enterprise can offer.
• Functionality may reside in different systems.
• Requires disparate applications to be connected into a larger,
integrated solution.

6. Integration – How?
• Architecting integration solutions is a complex task.
• There are many conflicting drivers and even more possible 'right'
solutions.
• No "cookbook" for enterprise integration solutions.
• Asynchronous messaging architectures have proven to be the
best strategy for enterprise integration because they allow for a
loosely coupled solution that overcomes the limitations of
remote communication, such as latency and unreliability.

7. Why Patterns?
Patterns are an excellent way to ensure:
1. Everyone understands the model taken – poses a design
problem and presents a solution
2. Common vocabulary
3. Use of best practices - experience base that architects have
gained by repeatedly building solutions and learning from
mistakes.
4. Faster development time – reuse of patterns and not reinvent
patterns

8. Outline
§ Enterprise Integration Patterns (EIP) – Gregor Hohpe
§ Message Translator, Content-Based Router, etc.
§ Implementation of EIPs in WSO2 ESB
§ Low level patterns
§ Using functional components such as mediators, sequences
etc.
§ High level solution patterns
§ ESB Patterns – Concentrator, Security Proxy etc.
§ Overall Integration Patterns
§ e.g. API Gateway, Trusted subsystem etc.
§ Also see Integration Styles from EIP
§ Implementation of integration patterns using WSO2
products

9. Enterprise Integration Patterns
http://www.eaipatterns.com/
"The core language of EAI, defined in the
book Enterprise Integration Patterns by
Gregor Hohpe and Bobby Woolf, is also the
core language of defining ESB flows and
orchestrations, as seen in the ESB's
developer tooling."

10. Enterprise Integration Patterns
§ EIPs are patterns using asynchronous messaging as the style
of integration.
§ They are technology-agnostic which means it does not matter
what programming language or operating system you use.
§ Categorization of Patterns
• Messaging Channels
• Message Constructions
• Message Routing
• Message Transformation
• Messaging Endpoints
• System Management

11. WSO2 ESB is…
• A lightweight, high performance ESB
• Feature rich and standards compliant
• SOAP and WS-* standards
• REST support
• Domain specific protocol support (eg: FIX)
• User friendly and highly extensible
• 100% free and open source with commercial support

12. WSO2 ESB - Functional Components
• Mediators
• Sequences
• Endpoints
• Proxy Services
• Event Sources
• Priority Executors
• Message Stores
• Tasks
• Local Entries
• Registry

13. More on Functional Components
• Each functional component serves a specific
purpose
• Functional components can be mixed and
matched to implement various integration
scenarios and patterns
• Configuring WSO2 ESB for a given scenario
requires:
• Identifying the right set of components
• Putting them together in the optimal manner

14. Mediators
http://docs.wso2.org/wiki/display/ESB460/Mediators
Rich mediator library, wherein most cases a single
mediator can be directly mapped to an EIP.

15. List of Mediators
• Send
• Log
• Property
• Sequence
• Event
• Drop
• Enrich
• Filter
• Out
• In
• Switch
• Router
• Conditional Router
• XSLT
• URLRewrite
• XQuery
• Header
• Fault
• Cache
• Clone
• Store
• Iterate
• Aggregate
• Callout
• Transaction
• Throttle
• RMSequence
• DBReport
• DBLookup
• Rule
• Entitlement
• OAuth
• Class
• POJOCommand
• Script
• Spring
• Smooks

16. Sequences
• A chain of mediators
• Messages are sent through all the
mediators in the sequence, in the order
they appear

17. Enterprise Integration Patterns with WSO2 ESB
Complete Guide -
http://docs.wso2.org/wiki/display/IntegrationPatterns/Enterprise
+Integration+Patterns+with+WSO2+ESB
The guide shows how each pattern in the patterns catalog can be
simulated using various constructs in WSO2 ESB.
A selected few of the patterns will be discussed in this webinar.

18. Message Channel
A message channel is a logical channel which is used to connect
the applications.
One application writes messages to the channel and the other one
(or others) reads that message from the channel.
Message queue and message topic are examples of message
channels.

19. • Queues -
• With WSO2 ESB, a common pattern is to persist the
message from an incoming HTTP request into a persistent
message queue, and then process from there.
• WSO2 Message Broker, ActiveMQ etc. can provide the
persistent queue.
• Topics – Supported by ESB and Message Broker
• WSO2 ESB has an event distribution model and eventing
support.
• WSO2 Message Broker, the Apache QPid-based broker,
provides higher performance as well as supporting the JMS
API.
Message Channel continued

20. Message Translator
Message translator transforms messages in one format to another.
Can be implemented through several Mediators in WSO2 ESB –
• Enrich
• XSLT
• Smooks
• Payloadfactory
• XQuery

21. Publish-Subscribe Channel
• This type of channel broadcasts an event or notification to all
subscribed receivers.
• This is in contrast with a point-to-point channel. Each subscriber
receives the message once.
• The most common implementation of this pattern is messaging
topic.
• Event mediator.
• Topics – WSO2 ESB/ WSO2 Message Broker

22. Publish-Subscribe Channel continued

23. Dead Letter Channel
The Dead Letter Channel describes how messaging system
determines how to deliver a dead message to the specified
recipient.
This may be caused by connection problems or other exception like
overflowed memory or disc space.

24. Dead Letter Channel continued

25. Content-Based Router
Content-Based Router examines message contents and
route messages based on data contained in the
message.

26. Content-Based Router continued
Message routing is simulated by Switch and Send mediators
of the WSO2 ESB.
The Switch Mediator depicts the Router and observes the
content of the message while the Send Mediator is used to
send the message to a selected recipient.
Each case defined should decide on routing the message to
the appropriate service.

27. Content Enricher
Content Enricher as the name suggests enrich message with
missing information. Usually an external data source like a
database or a web service is used.

28. Content Enricher continued

29. Message Filter
Message Filter EIP checks an incoming message against a certain
criteria that the message should adhere to.
If the criteria is not met, the filter will discard the message.
Else, it will route the message to the output channel.
The Filter mediator in the ESB will check on the criteria.

30. Splitter/Aggregator
The Splitter EIP - Processes messages containing multiple
elements.
Breaks out the composite message into a series of individual
messages.
The Aggregator EIP - Combines the results of individual messages
so that they can be processed as a whole.

31. Splitter/Aggregator continued
Splitter
Aggregator

32. Composed Message Processor
The Composed Msg. Processor EIP is used to process a
composite message.
It maintains the overall message flow when processing a message
consisting of multiple elements.

33. Composed Message Processor continues
• Use of Sequences
• Named Sequences
• Sequences in Proxy Services – In Sequence, Out
Sequence, Fault Sequence

34. WSO2 ESB Configuration Documented as EIPs

35. ESB Patterns
• It’s worth understanding the way the ESB is being used:
• ESB are not the same as network routers
• Can be used in multiple ways for Routing, Traffic filtering,
Transformation, Protocol Switching, Load balancing.
• More like a Swiss-army knife
• Be clear about how you intend to use it
• The same ESB can be implementing multiple patterns
• Anti-Patterns
• Implement all your business logic in the ESB

36. The Concentrator Pattern

37. EAI Hub
• Request Transformation
• ESB can split and clone messages.
• Response Transformation
• ESB can aggregate messages.
• Service chaining
• ESB can act as a lightweight orchestration engine.

38. Federated ESB Pattern
Enterprise ESB
Routing and
Audit
Department
ESB
Department
ESB
Department
ESB

39. Overall Integration Patterns
• API Gateway
• Service Broker/Trusted Subsystem
• Service Firewall
• Master Data Management
• Security Gateway
• Dual Channel/ Claim Check

40. WSO2 Product Stack

41. API Gateway
Business Problem
• Different Service platforms run on a variety of server hardware,
operating systems and development platforms.
• Services expose different communication and security patterns.
• Complexity in exposing the SOA to internal and external
consumers.

42. API Gateway
Solution
• An Approach to simplify and normalize interaction with
heterogeneous services.
• Define a unified generic service layer on-top of the existing
services to expose to the consumers.
• API Gateway Pattern is able to solve this business problem.

43. API Gateway

44. Service Broker/ Trusted Subsystem
Business Problem
• Backend services need to be relieved from authentication of
service clients.
• Security authentication needs to be handled before the call
reach the backend service.
Solution
• User authentication to be handled at the ESB layer.
• Backend service trust the ESB.
• ESB access backend service on-behalf of the authenticated
user.

45. Service Broker/ Trusted Subsystem

46. Service Firewall Pattern
Business Problem
• To expose internal business services to external service
consumers.
• To ensure that only authorized users access the services
exposed.
• To validate the user credentials before reaching the internal
network.
Solution
• Deploy a separate ESB to validate user requests.
• Achieve this by using a Service Firewall Pattern.

47. Service Firewall Pattern

48. Security Gateway Pattern

49. Master Data Management (MDM)
Business Problem
• Business organizations have legacy applications and databases
that store and manage master data.
• Managing master data is critical to make successful business
decisions.
• Present IT infrastructure is depended on SOA.
• Need a way to connect the Master Data with the SOA.

50. Master Data Management (MDM)
Traditional Approach

51. Master Data Management (MDM)
Solution
• To expose Master data as services in a SOA.
• Master Data Management Pattern is able to solve this problem.

52. Dual Channeling
Business Problem
• When large files are required to go through a workflow process.
• Moving files through the workflow is inefficient, creates
additional traffic, reduce the throughput.

53. Dual Channeling
Solution
• Dual Channel pattern avoids the above mentioned problems by
having two channels.
• For the metadata on file
• For the actual file
• A light-weight message with the file related metadata, to process
within the workflow.
• Metadata contains the pointer reference to the actual file.

54. Dual Channeling

55. Dual Channeling

56. Resources
• http://wso2.com/blogs/architecture
• http://www.eaipatterns.com/
• http://docs.wso2.org/wiki/display/IntegrationPatterns/Enterprise
+Integration+Patterns+with+WSO2+ESB

57. Questions?

58. Engage with WSO2
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• From project evaluation and inception to development
and going into production, WSO2 is your partner in
ensuring 100% project success

59. 59
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