do i still hate soa? javazone johannes brodwall, steria organized architect steria norway
TRANSCRIPT
Do I still hate SOA?
JavaZone
Johannes Brodwall, Steria Organized Architect
Steria Norway
Crazy trucker coder is right
What do I care about?
People(def: Users and programmers)
In large projects(def: 10-100 people)
In complex orgs(def: Where integration is
paramount)
(Frustration)
(Joy)
How we don’t want our projects to beArchitecture impacts people
Teams Produce Business-valueFeature oriented teams Simple technology
Reference architecture
ReuseCosts and benefits
Strategic and tactical
J Random
Consider John Random Developer
Rules Engine Team
Front End Team
Service Layer Team
PM
J Random
Jira
J Random
”User gets DataBindingException
when submitting payment (see attached SOAP msg)”
Test server
Payment svc
J Random
Reproduce…
Test server
Payment svc
J Random
J Random
Payment Service
Payment XML
Payment DTO
Domain
Rules DTO
Rules XML
Rules
Which of the layers is the bug in…?
Rules Engine Team
Front End Team
Service Layer Team
PM
J Random
You sent a new field: currency
Rules Engine Team
Front End Team
Service Layer Team
PM
J Random
You sent a new field: currency
Didn’t you get the memo?
J Random
Sigh!
Payment Service
Payment XML
Payment DTO
Domain
Rules DTO
Rules XML
Rules
J Random
Test serverNew version
J Random
Test server
New version
Test server
New version
J Random
Let’s test it out
Test server
J Random
Okay
Okay
OkayOkay
OkayOkay
Okay
Okay
Not okay
It look good. Waaait….
Test server
J Random
Okay
Okay
OkayOkay
OkayOkay
Okay
Okay
Not okay
Duh! Null pointer exception!
J Random
Test serverNew version
J Random
Test server
New version
How did it get to this?
J Random
What does the program do?
I’m just a small cog in a big
machine
What’s up with all this data shuffling?
Bad architecture
UI UI UI UI
Service Service Service Service
Data Data Data Data
Reused service Reused library
Bad architecture
Technol-orgy Reuse fixation
Team per component
Suffering
Rules Engine Team
Front End Team
Service Layer Team
PM
Of course the Front End guys can deal with
an empty list
Rules Engine Team
Front End Team
Service Layer Team
PM
I better check that field is
present
I better check that field is
presentI better check that field is
present
Rules Engine Team
Front End Team
Service Layer Team
PMI wonder if anyone will
use this
Rules Engine Team
Front End Team
Service Layer Team
PM
Done with A soon?
Rules Engine Team
Front End Team
Service Layer Team
PM
Done with A soon?
I’m done, I just have to wait for
the rules engine!
Rules Engine Team
Front End Team
Service Layer Team
PM
Done with A soon?
I’m done, I just have to wait for
the rules engine!… and then test it
Rules Engine Team
Front End Team
Service Layer Team
PM
Done with A soon?
I’m done, I just have to wait for
the rules engine!… and then test it
… and then fix that tiny bug
Rules Engine Team
Front End Team
Service Layer Team
PM
Done with A soon?
I’m done, I just have to wait for
the rules engine!
I better hurry with B, everyone’s
waiting
Bahamas!
Rules Engine Team
Overworked!
Proud dad!
Front End Team
Service Layer Team
PM
Baby
!
Bahamas!
Rules Engine Team
Overworked!
Proud dad!
Front End Team
Service Layer Team
PM
Can you guys help out?
Baby
Bahamas!
Rules Engine Team
Overworked!
Proud dad!
Front End Team
Service Layer Team
PM
Can you guys help out?
Baby
Would love to help, but I don’t
know rules engine
Overworked!
Rules Engine Team
Front End Team
Service Layer Team
PM
This iteration, Product Owner just wants to improve the UI
!
There is an alternative!
(There are many)
(And this is mine)
Organization Architecture
UI UI UI UI
Service Service Service Service
Data Data Data Data
Reused service Reused library
UI UI UI UI
Service Service Service Service
Data Data Data Data
Reused service Reused library
A feature teamIs connected to a user
Has a reference stack
Owns the whole stack
User:Human or machine
GUI
Logic
Data
Service
Machines are people, too!
Simplicity
SimplicityAvoid technolorgy
(My reference architecture)
Fewer deployed artifacts
Executable jar file
App Server (Jetty jar)
Web application (war)
ClientClient Jar (Java
Web Start)
Fewer maven modules
Server WAR
Core classes
Client JAR
Fewer external dependencies
Control instansiation
No DTO
Embedded app server
Boring choices
Messaging
MigrationsHibernate
Deployment
Packaging
FitNesse
Database
SOAP over httpEntitieshttp remoting
Monitoring
Unit tests
Commands
Scenarios
UI overview
Application Frame [http://server:8088/service]
Menu
Work area
Toolbar
PersonWindowPersonWindowWindow 2Window 2Etc.
UI calls server
TODO: Code action listener calls server
UI server
TODO: Command calls repo
TODO: Repository interface
RepositoryHibernateThe real deal
Very slow startup
HashMapIn memory fake
Quick startup
Used for unit tests
TODO: Repository interface
private Specification<Person> getSpecification() { return new FilterSpecification<Person>() { @Override public void populate(EntityFilter filter) { filter.propertyEqualsOrNull( "country", country); filter.propertyMatchesOrNull( "name", namePattern); } };}
@RunWith(RepositoryTestRunner.class)public class PersonWindowTest { private Repository repository; private PersonWindow personWindow; public PersonWindowTest(Repository repo) { this.repository = repo; this.personWindow = new PersonWindow(repo); }
@Testpublic void should_find_people() { Person person = new Person(“John Random"); repository.insert(person); personWindow.getSearchButton().doClick(); assertEquals(personWindow.getTableCell(0,1), person.getName());}
Integration
Transactional
File SystemFile
ScannerFile Writer
Message Responder
Repository
Scan
Move to tmp
Next message
CommitDelete file
Find data
Write response
Transactional
Next responseWrite to tmp
Commit
Move to targetTransactional
Hexagonal architecture
Application
UI
FileSystmAdapter
HttpSoapAdapter
Hibernate
Repository
Entities
Command
Dissent
Poll vs pushProgrammer provides proof
SQLBest requirement fit
Server abstractionDevelopers show the way
SpecificationDevelopers required better
abstractions
HibernateGo to Christin’s lightning talk
(T -24hrs)
Key points
Ubiquitious entities
Generic repository
Command oriented
A feature teamIs connected to a user
Has a reference stack
Owns the whole stack
Reuse
Don’t make
Strategic decisionbased on
Tactical reasons
Value of reuse
Value of reuse =
Cost of new dev – cost of reuse
Value of reuse =
Cost of new dev-cost of reusability
- cost of reusing
- cost of governance
Relative cost of writing for reuse:
125%-300%
Relative cost of writing for reuse:
125%-300%
Publishing
Input validation
Wider usage
Documentation
Testing
Relative cost of reuse:
10%-40%
Relative cost of reuse:
10%-40%
Learning
Not finding
Bugs
Finding
Adapting
Surface to volume ratio
Reuse governance
Client A 1.0 Client B 1.0
Enterprise Payment
Client A 1.0 Client B 1.0
Enterprise Payment
Client A 2.0 Client B 1.0
Enterprise Payment 2.0
Client A 2.0 Client B 1.0
Enterprise Payment 2.0
Client A 1.0 Client B 1.0
Service 1.0
Stable (AKA dead) service
Client A 2.0 Client B 1.0
Service 2.0
Service1.0
Library reuse
Client A 2.0 Client B 1.0
Service 2.0
Adapter
Multi version service
Client A 2.0 Client B 1.0
Magic box!! !
Service 2.0
Service bus
Value of reuse =
Cost of new dev – cost of reuse
High value
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EDIFACT
EDIFACT(The UN punishes those
who speak ill of XML)
High value
Medium value
java.util.Collection
Hibernate, Spring
Medium value
Low value
Apache commons
java.net.HttpURLConnection
Low value
Negativ value
Dozer
The library the other team made because
they didn’t like Dozer
The ”Save Customer” service
Negativ value
Strategic reuse
Strategic reuseHigh value
Often services
New functionality
Tactical reuse
Tactical reuseLow value
Often component
Reduce cost
Opportunistic
Don’t make
Strategic decisionbased on
Tactical reasons
Conclusion
What does this have to do with SOA?
What does this have to do with SOA?
(Very little)
Architectural choicesAffect people
Conway’s law
ReuseTactical vs strategic
Feature oriented team
As a programmer1. Meet the user
2. Own the whole stack
3. Speak your mind
As an architect1. Organize teams per feature
2. Simple reference architecture
3. Welcome dissent
Do you agree?
You haven’t learned a thing!
Please [email protected]
http://johannesbrodwall.com
http://sterkblanding.no
http://twitter.com/jhannes