The presentation is about real world and production ready example in reactive programming area, using Vert.x. It shows the best practices, event driven application architecture on the cloud and lessons learned.

1. Mariam Hakobyan,
Sascha Möllering,
| zanox AG
Björn Stahl
Real World Enterprise Reactive
Programming using Vert.x

2. TABLE OF CONTENTS
1.Introduction
2.The Beginning
3.How to start?
4.Best Practices
5.Architecture
6.Deployment
7.Vert.x module system
8.Integration with messaging system

3. INTRODUCTION ZANOX
Europe‘s leading performance advertising network

4. THE BEGINNING
Java Magazin 04.14:
Vert.x im Unternehmenseinsatz
Entwicklung und Betrieb von
asynchronen Applikationen mit Vert.x in
der Praxis

5. THE BEGINNING
● New core system for zanox
● Requirements are pretty high (not negotiable):
● Low latency
● High throughput
● Reactive
● Fast

6. THE BEGINNING
https://github.com/Mr-Steel/vertx_fatjar

7. WHAT IS VERT.X?
Vert.x
“Vert.x is a lightweight, high performance application
platform for the JVM that's designed for modern
mobile, web, and enterprise applications.”

8. WHAT IS VERT.X?
Polyglot

9. WHAT IS A VERTICLE?
● Classes with an own Classloader
● operates Single Threaded
● executed by an Event Loop

10. V V V W W W
Event Loop Pool
Event Bus
TAKE A LOOK INSIDE

11. HOW TO START?
● mvn archetype:generate -
Dfilter=io.vertx: (do not forget the
colon!)
● generates structure for all languages (JS,
Ruby, Groovy, Python)
● maven pom is already set with relevant data

12. HOW TO START?

13. Lessons learned - Profiling
● Verticles and WorkerVerticles appear in different
subtrees
● Be careful with blaming, a lot of stuff is just waiting
● If you think a verticle is a bottleneck: start more
instances of this verticle
● Measure every change & compare results (yeah yeah -
but really - do it!)

14. BEST PRACTICES
Starter Verticle

15. BEST PRACTICES
Logging

16. BEST PRACTICES
Logger Verticle
● Disadvantages:
● log entries are not in order
● loss of log levels
● Solutions:
●use IDs to follow log message flow
●use one LoggerVerticle per log level

17. BEST PRACTICES - On the fly deployment

18. BEST PRACTICES - On the fly deployment

19. BEST PRACTICES
In General
● Do not block the loop
● put blocking code or extensive computation into
worker verticles
● Keep the application responsive
● stress test as often as possible
● Encapsulate common code in modules (more
on this later)

20. BEST PRACTICES
Deployment
fat-jar: one package to rule the deployment

21. BEST PRACTICES
Deployment
zip-File:
● have a separate folder for scripts
● bind packaging to verify phase to have it all
with one command “mvn verify”
● complete example is on GitHub

22. Internet
Availability Zone
Auto Scaling group
Auto Scaling group
Availability Zone

23. Architecture

24. Architecture
● Main framework Vert.x
● mod-kinesis (Kinesis-Adapter for Vert.x)
● AWS Java SDK
● IAM roles for Amazon EC2 instances
● Coda Hale metrics and CloudWatch reporter
● Jedis (Redis client for Java)
● …

25. Deployment
Workstation
GitHub
Jenkins
Nexus
Python/Fabric
Datacenter
Artefakt

26. Deployment

27. Deployment
EC2 instance with Docker
registry (port 5000)
S3 bucket to store
Docker images

28. Deployment
Amazon Cloud
Workstation
GitHub
Jenkins
Python/Boto
Docker Image
Docker Registry S3 bucket with
Docker Images

29. Deployment

30. Deployment

31. Deployment

32. Deployment
python start_docker_instance.py
-r <myregistry>:5000
-i kinesis-producer
-t 95
-q 2
-s quality
-d '-d -p 8080:8080'
https://github.com/SaschaMoellering/aws-docker-scripts

33. Deployment
python start_elb.py
-r <myregistry>:5000
-i kinesis-producer
-t 95
-s quality
-d '-d -p 8080:8080'
https://github.com/SaschaMoellering/aws-docker-scripts

34. Deployment

35. Deployment

36. Vert.x Module System

37. Vert.x Module System
Benefits:
● Re-usable components as a zip file
● Maven and Bintray integration
● Vert.x module registry
● Vert.x downloads and installs modules for you

38. Vert.x Module Registry

39. Vert.x Event Bus
● Address is a simple string
● Types - Pub/Sub & P2P
Pub/Sub
P2P

40. Sender
Receiver

41. Integration with Messaging System
KAFKA MESSAGING SYSTEM
● Apache Kafka is a distributed publish-subscribe
messaging system
● Fast
● Scalable
● Durable
● Distributed

42. Integration with Messaging System
Main Terminology:
● Topic
● Producer
● Consumer
● Broker

43. Kafka Module in Module Registry
Open source Kafka module in Vert.x’ module registry
● http://modulereg.vertx.io/

44. Using Vert.x Module
// programmatically
// command line

45. Using Kafka Module
Configuration is a JSON object:

46. StatsD Support
Config

47. Metrics of Vert.x Project
On 4 Cores virtual machine we had the following
results:
●~28 K requests per second without Kafka,
with lookup from Redis
●~18 K requests per second with Kafka and
lookup from Redis

48. Metrics of Vert.x Project
Test Traffic ~1000-3000 requests per minute:
● mean response time: 1-2ms
● 90% of responses 0.86 ms
●fully cached: 0.65 ms
● CPU Load: 1-3%
● Memory: 90MB (300MB reserved)

49. GET INVOLVED
Kafka Module - https://github.com/zanox/mod-kafka
Kinesis Module - https://github.com/zanox/mod-kinesis

50. https://github.com/Mr-Steel/vertx_fatjar