PTW095: EventDriven SOA: EDA in an SOA World

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PTW-095 Event-Driven SOA EDA in an SOA World

• Ken Wilner
• Vice President of Technology

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Agenda

• The Case for Events
• Event-Driven Applications
• Events and SOA
• Events and OpenEdge RA
• Case Study
• Summary

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Business Events

• Meaningful change in enterprise
• Two types
• Routine normal part of business process
  pre-defined action
• Credit rating changed
• Enter an order
• Truck unloaded
• Stock traded
• Exception Events an unanticipated occurrence
  no pre-defined action
• A machine breaks down
• The weather delays a shipment
• An employee is late

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Software Event
An automated record, typically in the form of a
message, of a business event.
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Process Order
Process Order
Light Weight Request/Reply
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3
1
2a
Fulfill Order
ValidateOrder
Check Credit
Credit Rating
Heavy Weight Request/Reply
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Process Order Separate Polling Process
Process Order
Light Weight Request/Reply
2
3
1
Fulfill Order
ValidateOrder
Check Credit
Credit Rating
Heavy Weight Request/Reply Sent Periodically
Medium Weight Request/Reply
2a
2
1
CustomerMgmt
CheckCredit
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Process Order Event Driven Way
Light Weight Request/Reply
One-Way Event sent in Real Time
Medium Weight Request/Reply
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Invocation Models

• Request/Reply
• Request - a request to do something
• Reply - an indication that the request was
  processed
• Event
• an indication that something happened

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Request/Reply
Synchronous Bi-directional Communication
Please do this for me. Ill wait until I get the
reply.
Request
Consumer
Provider
Reply
Did it. Sorry it took me so long!!!

• Physical connection couples request/reply
• Consumer assumes reply received shortly after
  request sent
• Single provider receives each request implies
  limited flexibility

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Request/Reply Flow
Online Ordering Application
Supplier Service
Inventory Mgmt Service
Order Mgmt Service
Credit Services
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Event
Asynchronous uni-directional communication
It happened
Event Source
Event Sink
Event

• Each event sent independently of another
• No built-in coupling between messages implies
  gives flexibility and agility

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Event Flow
Fork
Join
Inventory Mgmt Service
Online Ordering Application
Order Mgmt Service
Shipping and Fulfilling
Credit Services
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Request/Reply vs. Events
asynchronous rpc
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Agenda

• The Case for Events
• Event-Driven Applications
• Events and SOA
• Events and OpenEdge RA
• Case Study
• Summary

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Events-Driven Application Models
Asynchronous One-way Communication

• Simple Events
• Brokered Events
• Enterprise Service Busses
• Event Stream Processing Engines

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Simple Event
Event
Event Source
Event Sink
It happened
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Simple Events Simulating Request/Reply
Request Event (req-id)
Event Source
Event Sink
Consumer
Provider
Reply Event (req-id)

• Req-id couples request/reply
• Reply sent independently of request
• Consumer assumes reply may be received along time
  after request

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Brokered Events
Event Source
Event Sink
Event
Event
Message Broker
Message
Event Sink
Event Source
Event
Event

• Event routed from source to one or more sink
• Optionally stored persistently until delivered

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Brokered Events Point to Point
Send to One Interested Party
Sender
Receiver
Event Source
Event Sink
connect
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Brokered Events Point to Point
Send to One Interested Party Multiple Receivers
Sender
Receiver
Event Sink
Event Source
Event Sink

• Event delivered to one receiver
• Multiple receivers promotes scalability
• All receivers are created equally

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Brokered Events Publish/Subscribe
Send to All Interested Parties
Subscribers
Publisher
Event Sink
Event Source
Event Sink
subscribe

• Event broadcast to all interested parties, e.g.
  Hot Deals
• Subscribers can be added dynamically

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Enterprise Service Bus Routed Events
Intelligent Routing
Event Source

• Combined with brokered event mechanisms
• Content-based routing

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Enterprise Service Bus - Orchestration Service
Sophisticated Process Flow
Event
Event
Event Source
Event Sink
ESB
Event Sink
Event Source
Event
Event

• Combines basic ESB services with long running
  stateful processes
• Supports looping constructs, state management,
  conditional constructs, fork thread, join, etc.
• Publish event, wait for event, etc.

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Event Stream Processing (ESP)
Aggregating and Correlating Events
IF PRGS Price lt PRGS VWAP THEN Buy PRGS
EventManager
EventStream
Event
Event Source
Event Sink
Events

• Filter rules
• Aggregation of events
• Event detection patterns

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Agenda

• The Case for Events
• Event-Driven Applications
• Events and SOA
• Events and OpenEdge RA
• Case Study
• Summary

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Service-Oriented Architecture
An approach for building distributedcomputing
systems based on encapsulating business functions
as services that can be easily accessed in a
loosely coupled fashion.
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How Do Events Support These Principles?

• SOA is good.
• Events are good.
• How do I marry the two????

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SOA Model
Loosely Coupled Components Communicating Via
Well-Defined Interfaces
ServiceDirectory
Contract
Find / Details
SOAInfrastructure
Publish
Service Consumer
Service Provider
Contract
Bind / Invoke
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Service Elements

• Presentation layer or another service
• Locates service provider through agreed upon
  service directory
• Binds/invokes service based service interface

Fn()
Service Consumer
Fn()

• Only the service interfaces are exposed
• Service implementation is hidden from the service
  consumer
• Data store encapsulated by service

Service Implementation
Service Provider
ServiceLogic
Data
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Service Contracts
Everything You Need to Know to Access the Service
Provider
Service Requestor
Service Provider
Contract

• Service Interface
• Service Location and Transport
• Service Description and Sequencing Requirements
• Error Handling
• SLAs

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SOA and Events
Event Sink
Event Source
Service Consumer
Service Provider
Notification
Event Sink
Event Source
Service Consumer
One-way
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SOA Architectural Layers
Application Client Layer
Business Process Services
ESB Orch. Service
Intermediary Services
Brokered EventsESP, ESB Routed Event
Basic Services
Simple Events
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Broker as an Intermediary Service
Service Consumer
Event Source
Event Sink
Event
Event
ServiceIntermediary
One-way
One-way
Message Broker
One-way
One-way
Service Consumer
Event
Event Sink
Event Source
Event
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Enterprise Service Bus Routed Events
Intelligent Routing
ServiceIntermediary
ESB
One-way
Event
Yes
Event
Service Consumer
Event Source
order count lt 100
One-way
No
Event
One-way
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Agenda

• The Case for Events
• Event-Driven Applications
• Events and SOA
• Events and OpenEdge RA
• Case Study
• Summary

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OpenEdge RA Service Components
Users
Enterprise Services
Service Consumer
Presentation Layer
Integration Layer
Business Servicing Layer
Data Access Layer
Service Provider
Managed Data Stores
Unmanaged Data Stores
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Business Layer Integration
Presentation Layer/s
Integration Layer/s
Service Adapter
Service Interface
Business Workflows
Business Tasks
Business Entities
Data Access Layers
Managed
Unmanaged
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Service Adapter/Interface Requirements
Service Consumer
Event-Driven Service Adapter
Service Provider
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Service Adapter/Interface Requirements
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Agenda

• The Case for Events
• Event-Driven Applications
• Events and SOA
• Events and OpenEdge RA
• Case Study
• Summary

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Sedgwick Claims Management Services, Inc.
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Sedgwick Event Driven SOA
Update Claim Info
Changed Fields From-value To-Value
Event Capture (DB Triggers)
Users
Event Generator/ Quenching
New Claim
Change Log
EMAIL ALERT
State-Changed Events
Enterprise Service Bus
RULES ENGINE Sub-System
State-Changed Events
Email
IVR
Rules Processing Engine
RULES DATABASE
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Agenda

• Event-Driven Applications
• Events and SOA
• OpenEdge RA and Events
• Case Study
• Summary

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In Summary

• SOA is the architecture for the agile business
• Events are great for maximum agility, and for
  building reactive systems
• Define the right services and use the right
  invocation method

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Questions?
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Thank you for your time!
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The Business Value of Software Events

• Efficiency
• Push technology
• Replaces polling or batch processing mechanisms
• Real-time monitoring of business state
• Parallel activities
• Agility
• Facilitates instance-level long running business
  processes
• Promotes flexible processes that are adaptable to
  changes in the business environment