This document summarizes Alberto Salazar's presentation on migrating a monolithic application to microservices after 10 years of development. It discusses the challenges of migrating over 2 million lines of highly coupled code. The presentation outlines a path for the migration, including steps to split the frontend from the backend, secure APIs, implement logging/monitoring, split databases, and consider frontend technologies. It emphasizes the need to maintain agility while managing the complexity of a distributed microservices architecture.

1. asalazar@advlatam.com
@betoSalazar
Part I - Second Edition: The Journey
How to Handle the Complexity
of Migrate to Microservices from Monolithic Ten year
Alberto Salazar,
CTO Advance Latam,
Auth0 Ambassador
24th April 2018

2. Alberto Salazar
● Speaker, Java Developer, #Community
● Auth0 Ambassador
● Java User Group Leader, JCP Member
@betoSalazar
@EcuadorJUG
@Auth0Ambassador
www.advlatam.com www.cloudbanco.com www.ecuadorjug.org
● Working 17 years with monolithic
● Founder and CTO: AdvanceLatam &
Cloudbanco

3. Legacy: Is our monolithic
@betoSalazar
Source: 97 Things Every Software Architect Should Know

4. Legacy: How it looks after 10 years of code
@betoSalazar

5. The journey
● The evolution of 10 years of code on Enterprise App
● Why to move from Monolith to Microservices
● The fact - 10 years of code
● The path - Tips, tricks, pros & cons of Microservices
● Conclusions
@betoSalazar

6. The evolution of more than 10 years of code
J2EE , JEE
App Server
or
Apache Felix OSGI
Apache Karaf
SOA
Industry approach
ESB
BPM
BAM
(-) external influence
Evolution
Frontend:
Html 5 Css3
Mobile
Split the monster
Microservices
the beginning
Microservices
Rest End points
Vert.x | Spring boot |
Micro-profile |
JEE -> Jakarta EE
NodeJS, Angular,
React, Native,
VueJS………………
……………………….
Devops
Docker
Kubernetes
Istio
Serverless
The vision behind the scenes
@betoSalazar

7. asalazar@advlatam.com
@betoSalazar
The motivation to migrate
from Monolith to Microservices

8. Microservices
@betoSalazar

9. Microservices ?
@betoSalazar
The buzz word
Microservices is the architectural approach that everybody talks about and everybody wants it,
but be prepare to manage a distributed system….

10. The Goal
@betoSalazar
VELOCITY
TIME
TO MARKET
The goal that organizations need is to increasing velocity & agility;
Get into production as soon as posible;
Deploy new features as soon as posible.

11. The journey
@betoSalazar

12. The reasons of this talk
@betoSalazar
The plan of move forward (Microservices -> cloud -> serverless ?)
Everybody are talking about the result (microservices architectural style)
but just a few are showing the painpath

13. asalazar@advlatam.com
@betoSalazar
The fact - 10 years of code
The Monolithic

14. Legacy: Is our monolithic
@betoSalazar

15. The Monolith
@betoSalazar
How it looks
http://microservices.io/patterns/monolithic.html

16. The Monolith
@betoSalazar
Characteristics
! Attachment to the environment(language, platform & OS)
! Single logical executable, deploy everything at once or nothing at all
! Bottlenecks and Failure of part == failure of whole
! Take months even years getting into production
! Centralized authority slows the delivery process (DBA, OPS, QA)
! Coordinated releases are hard, because brings many changes
together from different teams

17. How start this legacy
@betoSalazar
1 Year of code
Always the goal was to keep the modularization

18. Team work on the legacy
@betoSalazar
5 Years of code
Modularization ?

19. Really ?
@betoSalazar
10 Years of code
Modular WTF

20. 10 Years of code
@betoSalazar
OMG

21. Migrate several years of code, It will be Easy ?
@betoSalazar
The challenge
! > 2MM lines of highly coupled code
! Build one microservice is easy, but what
about a complete microservice architecture
based on 2MM lines of code
! Time to delivery features are between: 6 to
12 months & project overhead $$
! Working on production environment for
several years

22. asalazar@advlatam.com
@betoSalazar
The path - Tips, tricks, pros , cons
Microservices

23. The Monolith to Microservices
@betoSalazar
How it looks
http://microservices.io/patterns/monolithic.html http://microservices.io/patterns/microservices.html

24. Microservices
@betoSalazar
Characteristics
! Deployable, executable & scaled independently
! Smaller code modules are easier to understand
! High cohesion, low coupling
! Failure is isolated (Fail one part of the system)
! Independent Teams (decide their own
architecture)
! Polyglot “Plus”
https://martinfowler.com/articles/microservices.html
https://martinfowler.com/bliki/MicroservicePrerequisites.html

25. The path
@betoSalazar
Microservices
! Split the frontend from the backend & keep
the centralized data
! Secure your API
! Containers, logs, monitoring
! Split the data
! Don’t forget the frontend

26. JEE application server
The path -> Split the frontend from the backend
@betoSalazar
The Monolith (0/5)
Database
JEE application server
theApp.ear
MODULE1.war
MODULE1-JS.jar
MODULE2.war
MODULE3.war
css.war
MODULE4.war
businesslogic.jar
businesslogic.jar
businesslogic.jar
businesslogic.jar

27. @betoSalazar
Split the frontend from the backend (1/5)
JSF Controller Code
Call the Facade
The path -> Split the frontend from the backend

28. @betoSalazar
Split the frontend from the backend (1/5)
Facade Code
Call the Business
Logic
The path -> Split the frontend from the backend

29. JEE application server
theApp-backend.ear
businesslogi
businesslogi
businesslogibusinesslogic.jar
@betoSalazar
The communication
JEE application server
theApp.ear
MODULE1.war
MODULE1-JS.jar
MODULE2.war
MODULE3.war
css.war
MODULE4.war
Database
Message
Queue
Apache ActiveMQ
RabbitMQ
Apache Kafka……
http://activemq.apache.org
https://www.rabbitmq.com
https://kafka.apache.org
producer.jar
http://camel.apache.org/mdc-logging.html
consumer.jar
The path -> Split the frontend from the backend

30. @betoSalazar
Split the frontend from the backend
Use Camel Routes
Request - reply
Call the Processor
The consumer

31. @betoSalazar
The consumer
Split the frontend from the backend
Camel Processor Code
Call the Facade

32. @betoSalazar
JEE application server
theApp.ear
MODULE1.war
MODULE1-JS.jar
MODULE2.war
MODULE3.war
css.war
MODULE4.war
Database
Message
Queue
producer.jar
JEE application server
theApp-backend.ear
businesslogic.jar
consumer.jar
JEE application server
theApp-backend.ear
businesslogic.jar
consumer.jar
JEE application server
theApp-backend.ear
businesslogic.jar
consumer.jar
JEE application server
theApp-backend.ear
businesslogic.jar
consumer.jar
JEE application server
theApp-backend.ear
businesslogic.jar
consumer.jar
Split the backend
The path -> Split the frontend from the backend

33. @betoSalazar
Split the backend
https://projects.spring.io/spring-boot/
https://microprofile.io/
https://vertx.io/
https://www.docker.com/
https://github.com/fabric8io/docker-maven-plugin
https://github.com/spotify/docker-maven-plugin
Spring boot
install just
what you need
in a Docker
Container
Osgi container
engine-orchestrator.jar
Osgi container
dynamic-camel-routes.jar
fat jar
batch.jar
fat jar
services.jar
fat jar
business-module1.jar
fat jar
business-module-n.jar
Service
some api
Service
some api
Service
some api
Service
some api
Service
some api
Service
some api
businesslogic.jar
consumer.jar
businesslogic.jar
consumer.jar
businesslogic.jar
consumer.jar
businesslogic.jar
consumer.jar
businesslogic.jar
consumer.jar
businesslogic.jar
consumer.jar
The path -> Split the frontend from the backend

34. @betoSalazar
The path
Logging, trace & Monitoring
http://www.baeldung.com/mdc-in-log4j-2-logback
https://www.elastic.co/products/elasticsearch
https://www.elastic.co/products/logstash
https://www.elastic.co/products/kibana
logstash
1) Use Mapped Diagnostic Context (MDC)
Enrich log files
2) Introduce a correlationId
3) Collect the logs
4) Search by rest API or use Kibana
Osgi container
engine-orchestrator.jar
Osgi container
dynamic-camel-routes.jar
fat jar
batch.jar
fat jar
services.jar
fat jar
business-module1.jar
fat jar
business-module-n.jar
Service
some api
Service
some api
Service
some api
Service
some api
Service
some api
Service
some api
businesslogic.jar
consumer.jar
businesslogic.jar
consumer.jar
businesslogic.jar
consumer.jar
businesslogic.jar
consumer.jar
businesslogic.jar
consumer.jar
businesslogic.jar
consumer.jar
The path -> Split the frontend from the backend

35. JEE application server
theApp-backend.ear
businesslogic.jar
consumer.jar
JEE application server
theApp-backend.ear
businesslogic.jar
consumer.jar
JEE application server
theApp-backend.ear
businesslogic.jar
consumer.jar
@betoSalazar
JEE application server
theApp.ear
MODULE1.war
MODULE1-JS.jar
MODULE2.war
MODULE3.war
css.war
MODULE4.war
Database
Message
Queue
producer.jar
JEE application server
theApp-backend.ear
businesslogic.jar
consumer.jar
JEE application server
theApp-backend.ear
businesslogic.jar
consumer.jarRest API
rest-client.jar
Rest-api-layer
Rest-api-layer
Rest-api-layer
Rest-api-layer
Rest-api-layer
The path -> Split the frontend from the backend

36. @betoSalazar
https://docs.spring.io/spring/docs/current/spring-framework-
reference/web.html#mvc-introduction
Spring MVC
Osgi container
engine-orchestrator.jar
Osgi container
dynamic-camel-routes.jar
fat jar
batch.jar
fat jar
services.jar
fat jar
business-module1.jar
fat jar
business-module-n.jar
Service
some api
Service
some api
Service
some api
Service
some api
Service
some api
Service
some api
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
The path -> Split the frontend from the backend
Rest API

37. @betoSalazar
https://docs.spring.io/spring/docs/current/spring-framework-reference/web-reactive.html#spring-webflux
Spring Webflux
The path -> Split the frontend from the backend
Rest API

38. @betoSalazar
https://vertx.io/docs/vertx-core/java/
Vert.x
The path -> Split the frontend from the backend
Rest API

39. @betoSalazar
https://javaee.github.io/tutorial/jaxrs003.html
JAX-RS JEE 8
The path -> Split the frontend from the backend
Rest API

40. @betoSalazar
The path -> Secure your API
Osgi container
api-gateway.jar
Services
api rest
POST bank.com/api/v1/accouts
POST bank.com/api/v1/accouts
Secure your API
@betoSalazar
@EcuadorJUG
JWT
JSON WEB TOKEN
&
Authorization Server
https://jwt.io/
https://auth0.com
https://auth0.com/blog/implementing-jwt-authentication-on-
spring-boot/
https://auth0.com/blog/securing-spring-boot-with-jwts/
logstash
Osgi container
engine-orchestrator.jar
Osgi container
dynamic-camel-routes.jar
fat jar
batch.jar
fat jar
services.jar
fat jar
business-module1.jar
fat jar
business-module-n.jar
Service
some api
Service
some api
Service
some api
Service
some api
Service
some api
Service
some api
Database
Login
Angular nodejs
Transaction
Angular nodejs
Module n
Angular nodejs

41. @betoSalazar
https://auth0.com/blog/securing-spring-boot-with-jwts/
JWT + + Springboot + Spring Security
The path -> Secure your API

42. @betoSalazar
https://medium.com/@ryanchenkie_40935/angular-authentication-using-route-guards-bf7a4ca13ae3
https://github.com/auth0/angular2-jwt
JWT + AuthGuard with AngularSecure
App
The path -> Secure your Application

43. @betoSalazar
The path -> Discovery Services
https://hazelcast.org/
Discovery services to inspect or rely on the contents of any named IMap
Hazelcast
Discovery Services via IMDG
backbone of your Microservices architecture
POST bank.com/api/v1/accouts
Rest endpoints & API Gateway
fat jar
api-gateway.jar
Services
api rest
Osgi container
engine-orchestrator.jar
Osgi container
dynamic-camel-routes.jar
fat jar
batch.jar
fat jar
services.jar
fat jar
business-module1.jar
fat jar
business-module-n.jar
Service
some api
Service
some api
Service
some api
Service
some api
Service
some api
Service
some api
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer

44. @betoSalazar
The path
Split de database
https://flywaydb.org/
https://developers.redhat.com/promotions/migrating-
to-microservice-databases/
- Consistency Models:
Strong vs Eventual consistency
- Materalized views
- ETL Tools
Automate your database
migration
fat jar
api-gateway.jar
Services
api rest
logstash
POST bank.com/api/v1/accouts
POST bank.com/api/v1/accouts
Login
Angular nodejs
Transaction
Angular nodejs
Module n
Angular nodejs
Osgi container
engine-orchestrator.jar
Osgi container
dynamic-camel-routes.jar
fat jar
batch.jar
fat jar
services.jar
fat jar
business-module1.jar
fat jar
business-module-n.jar
Service
some api
Service
some api
Service
some api
Service
some api
Service
some api
Service
some api
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer

45. @betoSalazar
The path
Don’t forget the frontend & the agility
https://jwt.io/
https://nodejs.org/es/
https://facebook.github.io/react/
https://angular.io/
https://facebook.github.io/react-native/
fat jar
api-gateway.jar
Services
api rest
POST bank.com/api/v1/accouts
POST bank.com/api/v1/accouts
logstash
Login
Angular nodejs
Transaction
Angular nodejs
Module n
Angular nodejs
Osgi container
engine-orchestrator.jar
Osgi container
dynamic-camel-routes.jar
fat jar
batch.jar
fat jar
services.jar
fat jar
business-module1.jar
fat jar
business-module-n.jar
Service
some api
Service
some api
Service
some api
Service
some api
Service
some api
Service
some api
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
businesslogic.jar
Rest-api-layer
JWT
JSON WEB TOKEN
&
Authorization Server

46. Microservices Architecture
@betoSalazar

47. Containers - Orchestrators - Cloud
@betoSalazar
Istio: Service Mesh
Containers (Docker) ->
Manage the same code + environment in diferente stages
Orchestrators (Kubernetes, Docker Swarm, Mesos) ->
We need to orchestrated our containers
Cloud (eg. Oracle Cloud, Google Cloud, AWS, Azure, Bluemix)

48. asalazar@advlatam.com
@betoSalazar
Summary &
Code blueprints repositories

49. @betoSalazar
The conclusion
Microservices Architecture Losses
! Transactions
! Single data repository
! Better problems solver needed (Developers /
architects)
! the system and services have to deal with
network communications, failures, rebalances,
splits.

50. @betoSalazar
The conclusion
Recommendations
Design your application modular (either monolith, OSGi or microservices)
Continuously refactor your modules or microservices to achieve optimal boundaries
Monolithic apps only look simple from the outside, but you just open the box
Care about logs, monitoring and always use a CORRELATIONID and MDC (Mapped Diagnostic Context)
We need to deal with service load balance, monitoring, security

51. @betoSalazar
Recommendations
Use Docker + Kubernates + Istio
Automate the deployment and delivery process -> CI & CD -> DEVOPS Culture
Design for failover, Service load balancing and automatic scaling, data Separation,
Integrity, Performance
Use lightweight frameworks or java containers (Karaf, Vert.x, Spring boot, Microprofile
(Payara, WildFly Swarm, OpenLiberty, TomEE))
Secure your APIs - JWT json web token, Json Web Signature, Json Web Encryption
The conclusion

52. asalazar@advlatam.com
@betoSalazar
code blueprints:
https://github.com/lasalazarr/fastdev
https://github.com/lasalazarr/guide-monolithic-to-
microservices

53. asalazar@advlatam.com
@betoSalazar
THANK YOU
Auth0 Ambassadors.
Helping the developer community make the
internet safer.