Latest source code for this project can be found here: https://github.com/yunspace/dropwizard-mongodb-billapi Original reveal.js slides here: http://slides.com/yunzhilin/dropwizard-mongodb

1. Dropwizard MongoDBDropwizard MongoDB
One day prototype usingOne day prototype using ,,
andand
Yun Zhi Lin
DropwizardDropwizard MongoDBMongoDB
Google CloudGoogle Cloud
Yunspace.com +YunZhiLin @YunZhiLin

2. About - Yun Zhi LinAbout - Yun Zhi Lin
Computer Science @UNSW, Applied Finance @Macquarie
Joined a startup in 2002, then moved into Banking IT
Moonlights as a Web 2.0 (nosql, json, mobile) enthusiast
Loves Java without bloated frameworks or appservers
This project source code in GitHub

3. SpecSpec
End to end prototype of a Bill Aggregator that mimics vendor API.
See below for detail specifications.

4. Data ModelData Model
Providers - bill provider
Premises - location being provisioned for
Subscriptions - subscribe to bill by account/reference #
Bill - matching subscriptions trigger notifications
Notifications - Sent to subscription.callbackUrl with
UrlForBillRetrieval
FK: List(Subscriptions)
FK: List(Subscriptions)
FK: Provider.id, Premise.id, Bill.accountNumber, List(Bi
FK: Provider.id, Subscription.referenceNumber
FK: Provider, Premise, Subscription

5. ActorsActors
Producer - API hosted on Google Compute Engine
API Operations - Insert, List, Get, Remove, Path on all entities,
except Notification and Bill.
Consumer - Use
Sample Data - JSON files provided
Postman HTTP client

6. RequirementsRequirements
1. HTTP transport
2. JSON payload
3. Use compute engine
4. Authentication
5. API versioning
6. Ops-friendly
7. Data Validation
8. Batch considerations

7. DesignDesign

8. Frameworks ChoiceFrameworks Choice
Node.js - full stack JSON, but lacking expertise
Play! Framework - too complex for this exercise
Dropwizard - simple, war-less and proven

9. Database ChoiceDatabase Choice
Google Cloud Datastore - lacking expertise
MongoDB - perfect for JSON

10. Dropwizard + MongoDB = Meet RequirementsDropwizard + MongoDB = Meet Requirements
1. HTTP - Jersey RESTful web services
2. JSON - Jackson with Mongo-Jack, fastest Java parser
3. Use compute engine - Both API jar and DB hosted on GCE
4. Authentication - OAuth2 or custom Providers
5. API versioning - annotation based url mappings
6. Ops-friendly - healchecks and Codahale metrics
7. Data Validation - Hibernate Validatior
8. Batch considerations - use JSON lists

11. PlanPlan
Due to the time contraint, it's important to decide on the approach
taken to plan out a successfull prototype:
Start to End - build each component fully one by one, can only
partially demonstrate the story
Minimum Viable Product - selectively build only critical
operations for all components. So that together they tell a full
story

12. Scope AdjustmentScope Adjustment
Authentication - excluded
API versioning - excluded
Batch - simplified to single JSON parsing
Queuing - another consideration for the real world, excluded
Notification - manually triggered.

13. Final Use CaseFinal Use Case
Only the following Operations demonstrate the core processes of
subscription, notification and bill retrieval:
1. create a subscriptoin
2. Manually trigger notification, where UrlForBillRetrieval =
subscription.callbackURL + billID
3. retrieve a Bill
PUT /subscription/
GET /subscription/trigger/{subscriptoinID}/{billID}/
GET /bill/?billID={billID}

14. ImplementationImplementation
1. Build Tool
2. Configuration
3. MongoDB
4. Healthcheck
5. JSON POJOs
6. Resources
7. Application Glue
Build ToolBuild Tool

15. Gradle combines the best of Ant and Maven
repositories {
mavenLocal()
mavenCentral()
}
project.ext {
dropwizardVersion = '0.7.0-SNAPSHOT'
mongojackVersion = '2.0.0-RC5'
dropWizardConfig = './src/main/resources/billproto.y
}
dependencies {
compile 'io.dropwizard:dropwizard-core:' + dropwizar
compile 'org.mongojack:mongojack:' + mongojackVersio
testCompile group: 'junit', name: 'junit', version:
}
run {
args 'server', dropWizardConfig
} ConfigurationConfiguration
YAML

16. POJO
mongo:
host: ds039487.mongolab.com
port: 39487
db: tycoon-mongo
user: ####
password: ####
public class MongoConfiguration {
@NotNull
public String host;
@Min(1)
@Max(65535)
@NotNull
public int port;
@NotNull
public String db;
@NotNull
MongoDBMongoDB

17. public String user;
@NotNull
public String password;
}
Hosting - GCE option
Connection
JacksonDBCollection
DB Import (must be list of single line json files)
MongLab
mongo = new Mongo(mongoConfig.host, mongoConfig.port);
db = mongo.getDB(mongoConfig.db);
db.authenticate(mongoConfig.user, mongoConfig.password.t
bills = wrap(db.getCollection("bill"), Bill.class, Strin
dbCursor = bills.find().is("_id", billID);
if (dbCursor.hasNext()) { Bill result = cursor.next();}
mongoimport --host --username --password --db --collecti
HealthCheckHealthCheck

18. Code
Healthy
Not healthy:
@Override
protected Result check() throws Exception {
mongo.getDB(dbname).getCollectionNames();
return Result.healthy();
}
{"MongoHealthCheck":{"healthy":true},"deadlocks":{"healt
{"MongoHealthCheck":{"healthy":false,
"message":"not authorized for query on tycoon-mo
"error":{"message":"not authorized for query on
"stack":[...]JSON POJOsJSON POJOs

19. "deadlocks":{"healthy":true}}Use . Then apply simple
annotations for Jackson and Hibernate Validatior.
http://www.jsonschema2pojo.org/
@JsonInclude(JsonInclude.Include.NON_NULL)
public class Notification {
@Id
public String notificationID;
@NotNull
public String subscriptionID;
@NotNull
public String notificationURLForBillDataRetrival;
@NotNull
public String notificationURLForBillImageRetrival;
}
ResourcesResources

20. NOTE: Use @Id for UUID, not @ObjectIdAnnotate opertion, metrics, url path and output format.
Jackson automatically parse POJO into specified mediaType.
@GET
@Timed
@Path("trigger/{subscriptionID}/{billID}")
@Produces(MediaType.APPLICATION_JSON)
public Notification triggerNotification(
@PathParam("subscriptionID") String subscription
@PathParam("billID") String billID) {
...
notification = new Notification();
notification.notificationID = UUID.randomUUID().toSt
notification.subscriptionID = subscriptionID;
notification.notificationURLForBillDataRetrival =
subscription.subscriptionCallBackURL + "?billID=
return notification;
}

21. Application GlueApplication Glue
Putting all of the above together
@Override
public void run(
BillprotoConfiguration configuration,
Environment environment) throws Exception {
MongoManaged mongoManaged =
new MongoManaged(configuration.mongo);
environment.lifecycle().manage(mongoManaged);
environment.healthChecks().register(
"MongoHealthCheck", new MongoHealthCheck(mongoMa
environment.jersey().register(new SubscriptionResour
environment.jersey().register(new BillResource(mongo
}
DeployDeploy

22. 1. Install Java (defaults to OpenJDK)
2. Open firewall ports 8080 and 8081
3. Copy file to server
4. Run fatjar
sudo apt-get install java7-runtime-headless
gcutil addfirewall rest --description="http" --allowed
gcutil addfirewall admin --description="Iadmin" --allo
gcutil --project={project-id} push {instance-name} {lo
java -jar billproto-0.2-fat.jar server billproto.yml

23. TestingTesting
REST urlsREST urls
Subscription:
Trigger:
Bill:
Healthcheck:
162.222.183.244:8080/subscription/
162.222.183.244:8080/subscription/{subscriptionID}/{billID}
162.222.183.244:8080/bill/?billID={billID}
162.222.183.244:8081

24. ConclusionConclusion
By building just the bare minimum operations in each components
that work well together, we were able to cover the core user story
and better assess our API feasibility.
We also managed to test out a new framework and built a template
that can be fleshed out for future applications.

25. Links and CreditsLinks and Credits
built with
dropwizard.io
mongojack.org
gradle.org
This project source code in GitHub
This Slide reveal.js Export to PDF

26. QuestionsQuestions