MicroServices introduction presentation

1. MicroServices
Intro
by alex apollonsky
manahealth

2. Agenda
● Monolithic Architecture
● Monolithic Architecture Shortcomings
● MicroServices to help
● MicroServices Principles
● MicroServices Design Patterns
● MicroServices Key Technologies
● MicroServices Adoption Strategy Example

3. Monolithic Service
Monolithic Architecture
● Large Server-Side Process providing complete domain functionality
● Exposes multiple x-domain endpoints
● Deployed as a single unit
● Can be horizontally scaled by running multiple instances
● Example:
Authentication Administration Data Access Data Updates ...
HTTP Endpoints
Transactional Database

4. Monolithic Architecture Shortcomings
● Can be deployed only as single unit
● Regression Testing of the complete service required after every change
● Difficult to maintain good modular structure as service grows
● Complexity and amount of Unit and Integration Tests
● Difficult to coordinate team (or multiple teams) working on the same service

5. MicroServices to Help
● Smaller Independently Deployable Services
● Each Service relies on its own persistence layer where possible
● Manageable Unit/Integration Tests
● Not locked in into single technology/language
● Scalable across multiple teams
Authentication Administration Data Access Data Updates ...
HTTP Endpoints
Transactional Database
Service Data Service Data Service Data Service Data Service Data

6. MicroServices Principles
● Organized around Business Capabilities (Domain-Driven Design)
● Deploy separately, deploy in Containers
● Smart Endpoints and Dumb Pipes
○ Queues/Topics used for data transfer, not intelligent routing
○ Services are smart enough to pickup/process their data
● Coarser-grained communication approach
○ Changing in-memory calls to RPC or messaging will make it too chatty
○ May need to aggregate service logic
● Decentralized Data Management
○ Use independent persistence layer where makes sense
● Design with Versioning in mind
● Follow Single Responsibility Principle
○ Gather those things which change for the same reason, Separate those things which change for
the different reason
● Beware of nano-services

7. MicroServices Design Patterns: Aggregator (Proxy)

8. MicroServices Design Patterns: Chained

9. MicroServices Design Patterns: Register/Discover
Service A
Service Registry
(router)
Service B
Register
Service
Discover
Service

10. MicroServices Key Technologies
Docker - Container
Kubernetes - Container Orchestration (deployment/management)
Docker Swarm - another Container Orchestration
Mesos/Marathon - yet another Container Orchestration
Rancher - Orchestration UI console

11. MicroServices Adoption Strategy Example
● Plan/POC deployment/CI infrastructure
● Create MicroServices Project Template
● Start new services as MicroServices
● Migrate existing monolithic services to MicroServices architecture in the
background (out of critical path)
Research/POC Deployment/CI
MicroService
Template
Create New
MicroServices
Migrate Existing
Services

12. References
● https://martinfowler.com/articles/microservices.html
● https://en.wikipedia.org/wiki/Microservices
● http://microservices.io/patterns/microservices.html