The document discusses building a new service-oriented architecture at Allegro Group. It describes initial efforts to break the monolithic Allegro application into microservices using technologies like Spring, Jetty, Swagger, ZooKeeper and Docker. It outlines an approach of developing independent, discoverable services that communicate over REST APIs. The document also discusses improving the new architecture over time with features like authentication, monitoring, patching support and simplified annotations. Overall, it proposes building on modern tools and standards to scale Allegro's application and engage developers in the process.

1. @DebskiChris
#33rdDegree
Krzysztof Dębski
Allegro Group
Let’s build a solid base for a scale

2. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Agenda
The Allegro Situation
How to build a new World?
The way to improve
What’s in it for you?

3. Allegro The New World Improvement WIIFY
#33rdDegree @DebskiChris
The Allegro Situation

4. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Allegro

5. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Allegro
6 million LOC

6. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
400 people in IT
Allegro

7. Allegro The New World Improvement WIIFY
#33rdDegree @DebskiChris
A New Hope

8. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
A New Hope

9. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
A New Hope

10. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
A New Hope?
Service
Oriented
Ambiguity

11. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Domain Driven Design

12. Allegro The New World Improvement WIIFY
#33rdDegree @DebskiChris
(Micro)Services

13. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
(Micro)Services
Business needs
User
Transaction
Offer

14. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
(Micro)Services
Independent
User
Transaction
Offer

15. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
(Micro)Services
API
User
Transaction
Offer

16. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
(Micro)Services
Polyglot
Cassandra
MongoDB
Oracle
User
Transaction
Offer

17. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
(Micro)Services
Smart Endpoints
Cassandra
MongoDB
Oracle
Offer
Transaction
User

18. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
The first approach
Service
Auto deployable
Auto monitored
Auto scalable
Auto healable
Auto discoverable
… and many more features

19. Allegro The New World Improvement WIIFY
#33rdDegree @DebskiChris
How to build a new World?

20. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
The first project
Service
Jetty Server
War file
Spring
Gradle

21. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Let’s REST
JAX-RS / JSR Compliant
@Path("/users")
@Consumes(CONTENT_TYPE_JSON)
@Produces(CONTENT_TYPE_JSON)
public class UsersEndpoint {
// [...]
@GET
public UserCollectionResponse findAllUsers() {
//[...]
}
}

22. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Let’s expose our methods
Swagger
@Path("/users")
@Api(value = "/users")
@Consumes(CONTENT_TYPE_JSON)
@Produces(CONTENT_TYPE_JSON)
public class UsersEndpoint {
// [...]
@ApiOperation(value=“Get all users”,
response=UserCollectionResponse.class)
@GET
public UserCollectionResponse findAllUsers() {
//[...]
}
}

23. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Let’s expose our methods
Swagger
@Path("/users")
@Api(value = "/users")
@Consumes(CONTENT_TYPE_JSON)
@Produces(CONTENT_TYPE_JSON)
public class UsersEndpoint {
// [...]
@ApiOperation(value=“Get all users”,
response=UserCollectionResponse.class)
@GET
public UserCollectionResponse findAllUsers() {
//[...]
}
}

24. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Let’s expose our methods
Swagger

25. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
And make them discoverable
Offer
User
Discovery
ZooKeeper

26. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
And make them discoverable
Offer
User
Discovery
ZooKeeper
Register

27. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
And make them discoverable
Offer
User
Discovery
ZooKeeper

28. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
And make them discoverable
Offer
User
Discovery
ZooKeeper
Get User

29. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
And make them discoverable
Offer
User
Discovery
ZooKeeper
Get User

30. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
And make them discoverable
Offer
User
Discovery
ZooKeeper
Get User
Get offer for user

31. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Multiple API versions
Content negotiation
@Path("/users")
@Consumes(”application/json”)
@Produces(”application/json”)
public class UsersEndpoint {
// [...]
@GET
public UserCollectionResponse findAllUsers() {
//[...]
}
}

32. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Multiple API versions
Content negotiation
@Path("/users")
@Consumes(”application/vnd.allegro.user.v1+json”)
@Produces(”application/vnd.allegro.user.v1+json”)
public class UsersEndpoint {
// [...]
@GET
public UserCollectionResponse findAllUsers() {
//[...]
}
}
curl --dump-header - -H ”Accept: application/vnd.allegro.user.v1+json"
-X GET http://localhost:8080/users

33. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Multiple API versions
Content negotiation
@Path("/users")
@Consumes(”application/vnd.allegro.user.v1+json”)
@Produces(”application/vnd.allegro.user.v1+json”)
public class UsersEndpoint {
// [...]
@GET
@Produces(“application/vnd.allegro.user.v2+json”)
public UserCollectionResponse findAllUsers() {
//[...]
}
}
curl --dump-header - -H ”Accept: application/vnd.allegro.user.v2+json"
-X GET http://localhost:8080/users

34. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
And it became slow…

35. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Lower startup time
External Jetty Service
Jetty Server
War file

36. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Lower startup time
Embedded Jetty Service
Jetty Server
Jar file

37. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Lower startup time
Embedded Jetty Service
Jetty Server
Jar file

38. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Lower startup time
Embedded UnderTow Service
Jetty ServerUndertow
Jar file

39. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Lower startup time
Immutable Images Service
Undertow
Zip file
Server
Immutable image

40. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
How to configure it?
Service
java –jar service.jar

41. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
How to configure it?
Service ZooKeeper
java –jar service.jar –Dzookeeper.address=zookeper.service

42. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
How to configure it?
Service ZooKeeper
java –jar service.jar –Dzookeeper.address=zookeper.service –Denvironment=prod
prod.properties

43. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
How to configure it?
Service ZooKeeper
java –jar service.jar –Dzookeeper.address=zookeper.service –Denvironment=prod
-Dservice.name=testService
prod.properties

44. Allegro The New World Improvement WIIFY
#33rdDegree @DebskiChris
Tests

45. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Do you test your tests?
Pitest

46. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Integration tests
Test without mocks
Run from IDE
public class UsersIntegrationTest {
private static Map<String, String> overrideConfiguration = Maps.newHashMap();
static { overrideConfiguration.put("property.name", "This was overwritten value"); }
@ClassRule
public static final RestServiceStarted DEPLOYED_SERVICE =
new RestServiceStarted(overrideConfiguration);
private WebTarget getUsersResourceWebTarget() {
return DEPLOYED_SERVICE.getWebTarget().path("users");
}
}

47. Allegro The New World Improvement WIIFY
#33rdDegree @DebskiChris
Monitoring

48. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Let’s see what’s happening
NxLog
LogStash
Kibana

49. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Let’s see what’s happening
Graphite
# Metrics
metrics.reporters.graphite.enabled=true
metrics.reporters.graphite.host=graphite.service
metrics.reporters.graphite.port=2003
metrics.reporters.graphite.prefix=stats.Prod.service
metrics.reporters.interval=30

50. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Monolith Alert

51. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Monolith Alert
Multi module project support

52. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Monolith Alert
Multi module project support

53. Allegro The New World Improvement WIIFY
#33rdDegree @DebskiChris
The way to improve

54. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Authentication
OAuth2

55. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Patch Support
Standardized by IETF
https://tools.ietf.org/html/rfc6902
PATCH /user/1 HTTP/1.1
Host: user.service.local
Content-Length: 312
Content-Type: application/json-patch+json
[
{”op”: ”test”, ”path”: ”/firstname”, ”value”: ”Jane”},
{”op”: ”add”, ”path”: ”/maidenname”, ”value”: ”Smith”},
{”op”: ”replace”, ”path”: ”/lastname”, ”value”: ”Doe”},
{”op”: ”remove", ”path”: ”/meetings”},
{”op”: ”move”, ”from”: ”/balance”, ”path”: ”sharedbalance”},
{”op”: ”copy”, ”from”: ”/a”, ”path”: ”/b”}
]

56. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Simplify annotations
Swagger?
@Path("/users")
@Api(value = "/users")
@Consumes(CONTENT_TYPE_JSON)
@Produces(CONTENT_TYPE_JSON)
public class UsersEndpoint {
// [...]
@ApiOperation(value=“Get all users”,
response=UserCollectionResponse.class)
@GET
public UserCollectionResponse findAllUsers() {
//[...]
}
}

57. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Deployment
Docker support

58. Allegro The New World Improvement WIIFY
#33rdDegree @DebskiChris
What’s in it for you?

59. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Use the latest tools
GradleW in CI ENV and parent POM issues.
Don’t do DDOS yourself and your partners.

60. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Change is the only constant
Deployment tools
Service API provider
Dependency injection
HTTP Server
Cargo
Docker
Ecosystem
Swagger Jersey addon
Guice Spring
Jetty Undertow

61. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Focus on right metrics
How to have 100% code coverage?
public class UserMediaType {
public static final String V1_JSON =
"application/vnd.allegro.user.v1+json”
public static final String V2_JSON =
"application/vnd.allegro.user.v2+json”
}

62. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Focus on right metrics
import org.junit.Test;
import static net.trajano…
public class MediaTypesTest {
@Test
public void mediaTypesShouldBeValidUtilityClasses()
throws Throwable {
assertUtilityClassWellDefined(UserMediaType.class);
}
}
You don’t need 100% code coverage!

63. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Tools also lie
Metrics tend to lie
Configuration:
default PHP metrics
Tested file:
4535 CLOC
Imperative programming

64. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Tools also lie
How many violations are there?

65. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Tools also lie
How many violations are there?
4
At least according to Sonar.

66. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Learn to REST
REST is not so obvious
/api/bi/XYZ123/1
/recommendations/1/items
/offer/100?output=ESI/JSON

67. #33rdDegree @DebskiChris
Allegro The New World Improvement WIIFY
Community
Involve all developers in building the Bootstrap.
Or they will build their own tools.
Łukasz Drumiński Mateusz Gajewski
@wendigo

68. Allegro The New World Improvement WIIFY
#33rdDegree @DebskiChris
Q & A