1. Introduction to Microservices Prepared for
OpenLegacy Training
Day Four
Introduction to Microservices
Prepared for

2. Agenda Introduction to Microservices Microservice Architecture
Components and Frameworks
Inter-Process Communications
OpenLegacy Microservices

3. In the beginning, there was a Monolith …?
Explain about how applications were built before.
Explain the problem with the old “Monolith” architecture.

4. What is a Microservices Architecture?
Microservices architecture is a service‑oriented architecture composed of loosely coupled elements that have bounded contexts
Scale out vs. Scale up
If you keep scaling up, you’ll hit a limit
Horizontal scaling gives you a longer runway
Redundancy and Isolation For Resiliency
Make more than one of anything
Isolate the blast radius for any given failure
- Loosely coupled means that you can update services independently

5. Tight Coupling Doesn’t Work

6. Loose Coupling

8. Microservices Architecture Example

9. Components and Frameworks
Service Discovery (Netflix Eureka)
Gateway (Netflix Zuul)
Fault Tolerance (Netflix Hystrix)
Config Server (Spring Cloud)
UAA (Spring Security)
Log Analysis and Aggregation (ELK Stack)
- Fast slide, just to show the components in a list

10. Service Discovery Implemented using Netflix Eureka
Eureka is a REST (Representational State Transfer) based service that is primarily used in AWS cloud to locate services for load balancing and failover of middle-tier servers

11. Gateway Implemented using Netflix Zuul
Zuul is an edge service providing dynamic routing, monitoring, resiliency, security, etc.

12. Fault Tolerance Implemented using Netflix Hystrix
Hystrix is a Latency and Fault Tolerance library designed to isolate points of access to remote systems, services and 3rd party libraries, stop cascading failures and enable resilience in complex distributed systems where failure is inevitable

13. Config Server Spring Cloud Config Server features:
HTTP, resource-based API for external configuration (name-value pairs, or equivalent YAML content)
Encrypt and decrypt property values (symmetric or asymmetric)
Easily embeddable in a Spring Boot application
Config Client features (for Spring applications):
Bind to Config Server and initialize Spring Environment with remote property sources

14. UAA – User Account and Authentication
UAA is a multi-tenant Identity Management service
It is primarily an OAuth2 provider, issuing tokens for client applications to use when they act on behalf of business users
UAA can also act as an SSO service using those credentials (or others)
It has endpoints to manage user accounts and register OAuth2 clients, and a variety of other management functions

15. Log Analysis Logs are written using Spring Cloud Sleuth + Logback
We can monitor logs in real-time using Zipkin
Zipkin is a distributed tracing system. It helps gather timing data needed to troubleshoot latency problems in microservice architectures. It manages both collection and lookup of this data. Zipkin’s design is based on the Google Dapper paper.

16. Elasticsearch Logstash Kibana Log Aggregation
Writing, indexing and viewing of logs in a distributed environment is implemented with the ELK stack.
Elasticsearch
Logstash
Kibana

17. Elasticsearch

18. Logstash

19. Kibana

20. Inter-Process Communication (IPC)
Netflix Ribbon
Ribbon is a client-side IPC library that is battle-tested in Cloud
@LoadBalanced
Annotation to mark a RestTemplate bean to be configured to use a LoadBalancerClient

21. Demo

22. Deployment
Packaging
Docker
Cloud Foundry

23. Packaging JAR Spring Boot Maven plugin
A JAR (Java ARchive) is a package file format typically used to aggregate many Java class files and associated metadata and resources (text, images, etc.) into a single file for distribution
Spring Boot Maven plugin
Spring Boot Maven Plugin provides Spring Boot support in Maven, allowing you to package executable jars or war archives, and run an application “in-place”
Can be packaged as JAR or WAR
Can be deployed to traditional containers like Tomcat as a WAR
Can be ran anywhere as a “self-executable” JAR
Spring Boot also has a plugin for gradle

24. Docker Docker is the world’s leading software container platform
Dockerfile
Docker builds images automatically by reading instructions from a Dockerfile
Docker Compose
Compose is a tool to define and run multi-container Docker applications
We provide dockerfiles with all of our projects
We provide a default docker compose for the projects
We provide a default docker compose for the ELK stack (pre-configured for openlegacy)

25. Cloud Foundry
Cloud Foundry is the industry standard open source Cloud application platform to develop and deploy Enterprise Cloud applications.
Manifest
Manifest provides consistency and reproducibility, and helps automate deployment, especially of multiple concurrent applications
Cloud Foundry is the industry standard open source cloud application platform for developing and deploying enterprise cloud applications.
It automates, scales and manages cloud apps throughout their lifecycle.
Applications can be written in just about any language and are deployed in containers on multiple cloud infrastructures.
We provide default manifests for all of our projects

26. Exercise https://github.com/openlegacy/deloitte-training-2017
Username: ol-training
Password: training2017

27. Tom Fingerman tom.f@openlegacy.com

28. Questions? 
Tom Fingerman