This document summarizes a hands-on technical workshop on transforming applications from monoliths to microservices using reactive architectures with Eclipse Vert.x. The workshop introduces reactive systems and programming, demonstrates how Vert.x uses non-blocking execution models to handle high volumes with few threads, and guides participants through a lab to develop reactive microservices with Vert.x that interact asynchronously without blocking.

1. MONOLITHS TO MICROSERVICES: APP
TRANSFORMATION
Hands-on Technical Workshop
Ram Maddali
Senior Architect
@RamMaddali
rmaddali@redhat.com
Anand Akella
Senior Architect
aakella@redhat.com

2. REACTIVE MICROSERVICES

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The 2 faces of Reactive
Reactive
A software showing
responses to stimuli
Reactive
Systems
Reactive
Programming
Akka, Vert.x Reactor, RX, Vert.x
Actor, Agent
Autonomic
Systems
Data flow,
Functional
programming

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Execution Model (single core)
Blocking
● Example: CGI, early versions of server
side JavaScript.
● Can only scale horizontally
Multi thread
● Example: Java EE, Tomcat, Spring (non
reactive)
● Scales horizontally and vertically
Non blocking
● Example: NodeJS, Eclipse Vert.x, Akka,
Spring reactive
● Scales horizontally and vertically
Single Thread
Blocking
Single Thread
Non-blocking
Multi thread
= Execution Thread
= Request 1 = Request 2 = Request 3
Time
Reactive Systems
Request 1 waiting for DB
Multi Thread
Non-blocking

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Eclipse Vert.x
Vert.x is a toolkit to build distributed and reactive systems
● Asynchronous Non-Blocking development model
● Simplified concurrency (event loop)
● Reactive microservice, Web applications, IOT
● Ideal high-volume, low-latency applications
● Un-opinionated
● Understands clustering in its core architecture
Home - http://www.vertx.io

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VERT.X EVENT LOOP
EVENT
QUEUE
EVENT
LOOP
WORKER
THREADS
async
Handle Thousands of Requests
With Few Threads
response

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Vert.x Ecosystem

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● Explore Vert.x Maven project
● Create an API gateway
● Run Vert.x locally
● Deploy Vert.x on OpenShift
LAB 4: Reactive Microservices with Eclipse Vert.x

9. LAB: REACTIVE MICROSERVICES
WITH ECLIPSE VERT.X

10. GOAL FOR LAB
In this lab you will learn:
● How Event-based architectures supercharge microservice
apps
● Use cases for reactive applications
● Develop microservices using Eclipse Vert.x
● Interact with other microservices without blocking
● Learn the basics of Reactive programming

11. CURRENT STATE
OpenShift
coolstore-prod
Coolstore
monolith
Coolstore
database
(prod)
inventory
Inventory
microservice
Inventory
database
UI
Future Services
Future Services Future Services
Future Services
catalog
Catalog
microservice
Catalog
database

12. LAB: REACTIVE MICROSERVICES
SCENARIO 6 BUILDING REACTIVE MICROSERVICES

13. WRAP-UP AND DISCUSSION

14. RESULT OF LAB
In this lab you learned how to:
● Build reactive web application that are non-blocking
● Asynchronously call out to external service using Callbacks,
Handlers and Futures
● Deploy the application to OpenShift

15. RESULT OF LAB
OpenShift
coolstore-prod
Coolstore
monolith
Coolstore
database
(prod)
inventoryZ
Inventory
microservice
Inventory
database
catalog
Catalog
microservice
Catalog
database
cart
Cart
microservice
Cart
database
UI
checkout
Future Services

16. ECLIPSE VERT.X OFFER MUCH MORE

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SERVICE DISCOVERY
Service
Provider
Service
Provider
Service
Provider
Service
Consumer
Service
Consumer
Service
Consumer
Vert.x
Service
Registry
publish lookup
Bridge Bridge Bridge
import
Kubernetes Consul Other

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Vert.x vs NodeJS
2 threads per core
NodeJS Vert.x
Vert.x
● Multi-threaded
● Polyglot (Java, JavaScript, Scala, and more)
● Supports reactive programming using RxJava, RxJS, etc
NodeJS
● Single threaded
● JavaScript only
● Support reactive programming using RxJS

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FREE E-BOOKS
http://vertx.io/docs/

20. THANK YOU
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