© 2008 progress software corporation1 soa-33: transactions in a soa world what happens next? flight...
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© 2008 Progress Software Corporation1 SOA-33: Transactions in a SOA World
What happens next?
Flight Booking
Hotel Booking
Car Booking
(3) Calls
(2) Change DB
(5) Calls
(6) Fails
Client
(1) Calls
(4) Change DB
SOA-33: Transactions in an SOA World
(Practical Examples)
Mike OrmerodApplied Architect
© 2008 Progress Software Corporation3 SOA-33: Transactions in a SOA World
Definition : Transaction
“A transaction is a set of related changes to the database that the database either
completes in its entirety or discards, leaving no modification to the database.”
OpenEdge® Development: ABL Handbook
© 2008 Progress Software Corporation4 SOA-33: Transactions in a SOA World
ACID Properties
Atomic – All or nothing Consistent – Start & End in a Consistent state Isolated – transactions appear isolated from
all other operations Durable – once notified, the transaction will
persist
© 2008 Progress Software Corporation5 SOA-33: Transactions in a SOA World
Definition : Distributed Transaction
“A distributed transaction is a single transaction that updates two or more
databases.”
OpenEdge Data Management: Database Admin
© 2008 Progress Software Corporation6 SOA-33: Transactions in a SOA World
SOA Transactions
Functionality separated into Services• Application comprises many Services
Services as a separate platform System Independent Entities
© 2008 Progress Software Corporation7 SOA-33: Transactions in a SOA World
SOA Transaction Issues
Multiple services resulting in multiple endpoints
Loosely coupled systems• Maintaining Txn’s only possible in closely
coupled systems Services based on any platform Resources can’t be kept in a locked state Alternate Recover methods
ARCH-13: Transactions in an SOA World
© 2008 Progress Software Corporation8 SOA-33: Transactions in a SOA World
What’s needed
Uniquely identify transaction across services Guarantee that data is delivered and
notifications sent Some form of compensation for when it goes
wrong Handle errors in asynchronous services
© 2008 Progress Software Corporation9 SOA-33: Transactions in a SOA World
Possible Solutions
1. Compensation
2. Transaction Coordinator
© 2008 Progress Software Corporation10 SOA-33: Transactions in a SOA World
Definition : Compensation
“Compensation is an action taken when something goes wrong or when there is a
change of plan.”
IBM Systems Journal– April 2002
© 2008 Progress Software Corporation11 SOA-33: Transactions in a SOA World
Compensation
Flight Booking
Hotel Booking
Car Booking
(3) Calls
(2) Change DB
(5) Calls
(6) Fails
(7) Error/Exception
thrown
(8) Return error
(9) Call Compensation
(10) Apply
Compensation
(14) Return Failure
Client
(1) Calls
(4) Change DB
(11) Return Error
(12) Call Compensation
(10) Apply
Compensation
© 2008 Progress Software Corporation12 SOA-33: Transactions in a SOA World
Compensation Issues
Asynchronous services Where to store state details
© 2008 Progress Software Corporation13 SOA-33: Transactions in a SOA World
Definition : Transaction Coordination
“Orchestration of transactions through a transaction manager or process
coordinator.”
SOA Systems – Feb 2007
© 2008 Progress Software Corporation14 SOA-33: Transactions in a SOA World
Coordination Advantages
Fixes Asynchronous issues of Compensation Manages state & service information Central management of transaction &
compensation
© 2008 Progress Software Corporation15 SOA-33: Transactions in a SOA World
Coordination Service
Service 1 Service 2 Service 3
Coordinator Service
(2) Call
(5) Call
(6) Change DB
(7) Return (8) Call
(9) Fails
(10) Return
Fail(11) Call
Compensation
(12) Apply
Compensation
(13) Return(16) Return
Client
(1) Call
(3) Change DB(15) Apply
Compensation
(4) Return
(14) Call
Compensation
(17) Return
Fail
© 2008 Progress Software Corporation16 SOA-33: Transactions in a SOA World
OpenEdge Reference Architecture
PresentationPresentation
Business ComponentsBusiness Components
Data AccessData Access
Data SourcesData Sources
Co
mm
on
Infrastru
cture
Co
mm
on
Infrastru
cture
Enterprise ServicesEnterprise Services
© 2008 Progress Software Corporation17 SOA-33: Transactions in a SOA World
Vacation Booking - ABL
Flight Booking
Hotel Booking
Car Booking
Coordinator Service
(2) Call
(5) Call
(6) Change DB
(7) Return (8) Call
(9) Fails
(10) Return
Fail(11) Call
Compensation
(12) Apply
Compensation
(13) Return(16) Return
Client
(1) Call
(3) Change DB(15) Apply
Compensation
(4) Return
(14) Call
Compensation
(17) Return
Fail
Business ComponentsBusiness Components
Data AccessData Access
Business ComponentsBusiness Components
Data AccessData Access
Business ComponentsBusiness Components
Data AccessData Access
Business WorkflowBusiness Workflow
© 2008 Progress Software Corporation18 SOA-33: Transactions in a SOA World
Vacation Booking - ESB
Service 1 Service 2 Service 3
Coordinator Service
(2) Call
(5) Call
(6) Change DB
(7) Return (8) Call
(9) Fails
(10) Return
Fail(11) Call
Compensation
(12) Apply
Compensation
(13) Return(16) Return
Client
(1) Call
(3) Change DB(15) Apply
Compensation
(4) Return
(14) Call
Compensation
(17) Return
Fail
Enterprise Service BusEnterprise Service Bus
© 2008 Progress Software Corporation19 SOA-33: Transactions in a SOA World
Vacation Booking - BPEL
Service 1 Service 2 Service 3
Coordinator Service
(2) Call
(5) Call
(6) Change DB
(7) Return (8) Call
(9) Fails
(10) Return
Fail(11) Call
Compensation
(12) Apply
Compensation
(13) Return(16) Return
Client
(1) Call
(3) Change DB(15) Apply
Compensation
(4) Return
(14) Call
Compensation
(17) Return
Fail
Enterprise Service BusEnterprise Service Bus BPEL Service
© 2008 Progress Software Corporation20 SOA-33: Transactions in a SOA World
In Summary
ACID is good, taken in short doses! Plan, Design & Architect for target
implementation Choose the appropriate transaction model for
you Consider ESB & BPEL
© 2008 Progress Software Corporation21 SOA-33: Transactions in a SOA World
Questions?
© 2008 Progress Software Corporation22 SOA-33: Transactions in a SOA World
Thank You
© 2008 Progress Software Corporation23 SOA-33: Transactions in a SOA World