Introduction to Microservices Architecture, how it is differs from monolithic architecture, benefits, drawbacks and solutions.

1. Introduction to
Microservices
Architecture

2. What is Application Architecture?
The process of defining a structured solution that
meets all of the technical and operational
requirements, while optimizing common quality
attributes such as performance, security, and
manageability.

3. Key Principles of Application Architecture
• Scalability
• Maintainability
• Customizability
• Deployment Strategy

4. Scalability
Scale cube
Y axis - functional decomposition
Splitting different things
X axis - horizontal duplication
cloning
Z axis - data partitioning
Splitting similar things

5. Maintainability
• Simple to modify
• Easy to find solutions for bugs
• Decrease the participation cost
• Decrease maintenance effort

6. Customizability
• Configurable parts
• Modularity

7. Deployment Strategy
• Performance
• Security
• Availability
• Monitoring
• Scalability

8. What we are doing?

9. Traditional
Monolithic
Architecture

10. Monolithic Architecture
DB
AdapterRest
Adapter
Web UI
SMS
Adapter
Email
Adapter
Twilio
Send
Grid
Payments
Billings Notifications
Products
Customers

11. Monolithic Architecture is simple to:
• Develop
• Test
• Deploy
• Scale

12. Monolithic Architecture Drawbacks
For Large Applications
• High participation cost
• Overloaded IDE
• Continuous deployment is difficult
• Scaling the application can be difficult
• Obstacle to scaling development
• Requires a long-term commitment to a technology
stack

13. So
what can we do?

14. Microservices
Architecture
Tackling the Complexity

15. What are Microservices?
• Split the application into set of smaller, loosely
coupled services.
• Each microservice is a mini‑application that has
its own architecture consisting of business logic
along with various adapters.
• Some microservices would expose an API that’s
consumed by other microservices or by the
application’s clients. Other microservices might
implement a web UI.

16. Microservices Architecture
DB
Adapter
Api
Gateway
Web UI
SMS
Adapter
Email
Adapter
Twilio
Send
Grid
Payments
Billings
Notifications
Products
Customers
Microservices

17. Key Principles of Microservices Architecture
• Services communication Protocol (ex: REST, SOAP or
AMQP)
• Client interaction
• Database distribution per microservice
• Scalability per microservice
• Service discovery mechanism
• Data inter-services passing (ex: Security token)

18. Microservices Architecture Benefits
• Better testability
• Continuous deployment is simple
• Better team management
• Less participation cost
• Faster IDE
• Improved fault isolation
• Each service can be scaled independently
• Eliminates any long-term commitment to a technology stack

19. But
There are no silver bullets

20. Microservices Architecture Drawbacks
• Additional complexity
• Partitioned database architecture
• Multiple client endpoints
• Service discovery (Client, Server)
• Duplicate data
• Complex interconnected services testing
• Complex deployment
• Multiple services changes - relatively rare

21. Microservices Architecture Drawbacks
Partitioned Database
• Update multiple databases owned by different
services, where distributed transactions is usually
not an option
• Different kinds of databases
• Rollback mechanism
• Relational queries
• Consistency … Consistency … Consistency

22. Microservices Architecture Drawbacks
Partitioned Database
Order
Service
Customers
Service
Id Credit LimitId Customer Id Status

23. Microservices Architecture Drawbacks - Partitioned Database
Event‑Driven Architecture
Order
Service
Customers
Service
Id Credit LimitId Customer Id Status
Message
Broker
Order Created
Credit Reserved
Order Published

24. Microservices Architecture Drawbacks - Partitioned Database
Event‑Driven Architecture
Order
Service
Customers
Service
Id Credit LimitId Customer Id Status
Message
Broker
Order Created
Credit Limit Exceeded
Order Declined

25. Microservices Architecture Drawbacks - Partitioned Database
Event‑Sourcing Architecture
Command Query Responsibility Segregation (CQRS)
Order
Service
Customers
Service
Id Event Type State
Order Created
Order
Approved
Add Events
Find Events
Subscribe to Events

26. Microservices Architecture Drawbacks
Multiple client endpoints
• The mismatch between the needs of the client and the
fine‑grained APIs exposed by each of the microservices
• Different clients need different data
• Network performance is different for different types of
clients
• Service instances and their locations (host+port)
changes dynamically
• Services might use a diverse set of protocols

27. Microservices Architecture Drawbacks
Multiple client endpoints
Order
Service
Customers
Service
Mobile
?

28. Microservices Architecture Drawbacks - Multiple client endpoints
API Gateway
Order
Service
Customers
Service
Mobile
API Gateway

29. Microservices Architecture Drawbacks
Service discovery
• Each instance of a service exposes a remote API such
as HTTP/REST. at a particular location (host and port)
• The number of services instances and their locations
changes dynamically.
• Virtual machines and containers are usually assigned
dynamic IP addresses.
• The number of services instances might vary
dynamically. For example, an EC2 Autoscaling Group
adjusts the number of instances based on load.

30. Microservices Architecture Drawbacks
Service discovery
Service
Client
Customers
Service
? Order
Service
Dynamic IP
Dynamic IP

31. Microservices Architecture Drawbacks - Service discovery
Server-side service discovery
Service
Client
Customers
Service
Order
Service
Router
Service
Registry
Query

32. Microservices Architecture Drawbacks - Service discovery
Client-side service discovery
Service
Client
Customers
Service
Order
Service
Service
Registry
Query
Registry
Aware Http
Client

33. References
• https://www.nginx.com/blog/introduction-to-
microservices/
• http://microservices.io
• Google … Google … Google

34. Thank You