Video and slides synchronized, mp3 and slide download available at URL http://bit.ly/TJhC44. Brandon Byars discusses the constraints and the flexibility of nonpublic APIs, and lessons learned from scaling RESTful integration across more than a dozen teams. Filmed at qconlondon.com. Brandon Byars is a technologist and principal consultant at ThoughtWorks. He has a wide range of experience in multiple technologies and business domains, with an interest in applying systems thinking to software development. Brandon has a particular interest in exploring the social and organizational aspects that allow software development to scale to large teams.

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Watch the video with slide
synchronization on InfoQ.com!
http://www.infoq.com/presentations
/constraints-api-rest-integration

3. Presented at QCon London
www.qconlondon.com
Purpose of QCon
- to empower software development by facilitating the spread of
knowledge and innovation
Strategy
- practitioner-driven conference designed for YOU: influencers of
change and innovation in your teams
- speakers and topics driving the evolution and innovation
- connecting and catalyzing the influencers and innovators
Highlights
- attended by more than 12,000 delegates since 2007
- held in 9 cities worldwide

4. enterprise REST
a case study
twitter:@BrandonByars!

5. the eight fallacies of distributed
programming
• the network is reliable
• latency is zero
• bandwidth is infinite
• the network is secure
• topology doesn’t change
• there is one administrator
• transport cost is zero
• the network is
homogenous

6. POX
URI Resources!
HTTP Standard
Interface!
HATEOA
S
Forcing
people to use
your links!
RPC / SOAP!

7. Most REST mistakes
happen over here…!
versioning
deployment
testing
service
POX
URI
HTTP
HATEOA
S

8. REST

9. a story about a billing
system...

10. a story about a legacy
rewrite...

11. dramatis
personae

12. dramatis
personae
order
management
order
entry
provisioning
product
catalog
customer
field
force
management
address
billing
inventory:
physical
inventory:
telephony
CSR
UI
Web

13. Choreography...
...not orchestratio

14. define logical
environments
for isolation

15. Shared Integration VM!
Bob’s Workstation!
Order!
O1!
Product! P1!Mary’s Workstation!
Order!
O1!
Customer! C1!

16. Shared Integration VM!
Bob’s Workstation!
Order!
O1!
Product! P2!Mary’s Workstation!
Order!
O1!
Customer! C1!
Product! P1!
Customer! C2!

17. Shared Integration VM!
Bob’s Workstation!
Order!
O1!
Product! P2!Mary’s Workstation!
Order!
O1!
Customer! C1!
Product! P1!
Customer! C2!

18. Shared Integration VM!
Bob’s Workstation!
Order!
O1!
Product! P2!Mary’s Workstation!
Order!
O1!
Customer! C1!
Product! P1!
Customer! C2!
Bob’s Environment!
Mary’s Environment!

19. coordinated
deployments

20. order-bob:!
product:!
webServers: [s1.test.dev] !!
url: http://s1.test.dev:8000/products!
dbServer: s1.test.dev!
dbName: OrderBobProducts!
customer:!
webServers: [s1.test.dev]!
url: http://s1.test.dev:8001/customers!
dbServer: s1.test.dev!
dbName: OrderBobCustomers!
!
order-mary:!
product:!
webServers: [s1.test.dev]!

21. order-bob:!
product:!
webServers: [s1.test.dev] !!
url: http://s1.test.dev:8000/products!
dbServer: s1.test.dev!
dbName: OrderBobProducts!
customer:!
webServers: [s1.test.dev]!
url: http://s1.test.dev:8001/customers!
dbServer: s1.test.dev!
dbName: OrderBobCustomers!
!
order-mary:!
product:!
webServers: [s1.test.dev]!

22. version as a last
resort

23. 5.13.3!
4.1.1!
Product!
Order
Entry!
UI!
Billing!

24. {!
"customer": {!
"firstName": "Fred",!
"LastName": "Flinstone"!
}!
}!
{!
"customer": {!
"firstName": "Fred",!
"lastName": "Flinstone"!
}!
}!
speling mistaeks

25. @RequestMapping(method=POST, produces=application/json)!
@ResponseBody!
public OrderResource createOrder(!
!@RequestBody Order order,!
!HttpServletResponse response!
) throws OrderException!
{!
!...!
!...!
}!
Postel’s Law

26. separate functional testing
from integration testing

27. Automated!
Tests!
Showcase! SIT! Pre-prod! Production!Commit!
2.16.1!3.0.6!3.0.6!3.1.3!3.1.11!3.1.12!
deployment pipeline

28. Isolated
Pipelines!
SIT! Pre-prod! Production!
2.16.1!3.0.6!3.0.6!3.1.3!Order Entry!
Billing!
Product!
UI!
4.1.1!4.1.2!4.2.0!4.2.3!
7.2.0!7.2.0!7.2.0!7.2.6!
2.1.33!2.2.0!2.2.0!2.2.5!
deployment pipelines...

29. Isolation
Tests!
…! …! …! …!Commit!
2.16.1!3.0.6!3.0.6!3.1.3!3.1.11!3.1.12!
early stages
stub ruthlessly

30. System
Under
Test!
Tests!
Stub
Server!
hand-crafted stubs

31. System
Under
Test!
Tests!
Stub
Server!
record and replay stubs
Real!
Dependency!

32. System
Under
Test!
Tests!
Stub
Server!
general purpose stubs
Stub!
Setup!

33. Moco: https://github.com/dreamhead/moco !
vcr: https://github.com/vcr/vcr!
!
βetamax: https://github.com/robfletcher/betamax!
!
stubby4j: https://github.com/azagniotov/stubby4j!
!
!
mountebank: http://www.mbtest.org/!

34. Isolation
Tests!
…! …! …! …!Commit!
2.16.1!3.0.6!3.0.6!3.1.3!3.1.11!3.1.12!
early stages

35. Isolation
Tests!
…! …! …! …!Commit!
2.16.1!3.0.6!3.0.6!3.1.3!3.1.11!3.1.12!
early stages
Contract
Tests!

36. Isolated
Pipelines!
Contract!
Tests!
Pre-prod! Production!
2.16.1!3.0.6!3.0.6!3.1.3!Order Entry!
Billing!
Product!
UI!
4.1.1!4.1.2!4.2.0!4.2.3!
7.2.0!7.2.0!7.2.0!7.2.6!
2.1.33!2.2.0!2.2.0!2.2.5!

37. Contract!
Tests!
Artifacts!Isolated
Pipelines!
Tests!
3.1.2!Order Entry!
Billing!
Product!
UI!
3.1.3!
Tests!
4.2.3!
7.2.6!
Tests!
2.2.5!

38. Contract!
Tests!
Artifacts!Isolated
Pipelines!
Tests!
3.1.3!Order Entry!
Billing!
Product!
UI!
3.1.3!
Tests!
4.2.3!
7.2.6!
Tests!
2.2.5!

39. 7.2.6!
4.2.3!
Product!
Order
Entry!
UI!
Billing!

40. Contract!
Tests!
Artifacts!Isolated
Pipelines!
Tests!
3.1.3!Order Entry!
Billing!
Product!
UI!
Tests!
4.2.3!
7.2.6!
Tests!
2.2.5!
Order
Entry-3.1.3!
Billing-4.2.3!
Product-7.2.6!
UI-2.2.5!

41. Contract!
Tests!
Artifacts!Isolated
Pipelines!
Tests!
3.1.3!Order Entry!
Billing!
Product!
UI!
Tests!
4.2.3!
7.2.6!
Tests!
2.2.5!

42. [Test]
public
void
ValidateProductAttributes()
{
var
url
=
UrlForTestProduct();
var
response
=
new
HttpResource(url)
.ThatAccepts("application/xml")
.Get();
Assert.That(response.StatusCode,
Is.EqualTo(200));
AssertHasXPath(response.Body,
"//productCode");
AssertHasXPath(response.Body,
"//description");
AssertHasXPath(response.Body,
"//monthlyCharge");
AssertNumeric(ValueFor(response.Body,
"//monthlyCharge"));
}

43. use bounded contexts
to control complexity

44. Rates! CSR UI!
Provisioning!Finance!
Billing! Invoicing!
Marketing /!
Website!
Product!
Catalog!

45. data rationalization

46. Conway’s Law
Organizations which design
systems ... are constrained to
produce designs
which are copies of the
communication structures of these
organizations
In every organization there will
always be one person who knows
what is going on. This person must
be fired.

48. product!
finance!
invoice!
billing!
create!
record event!
get events!
augment!
augment!
augment!

49. twitter:@BrandonByars!
http://martinfowler.com/articles/enterpriseREST.html!

51. Watch the video with slide synchronization on
InfoQ.com!
http://www.infoq.com/presentations/constraints
-api-rest-integration