Microservice composition or integration is probably the hardest thing in microservices architecture. Unlike conventional, centralized ESB-based integration, we need to leverage the smart-endpoints and dumb pipes terminology when it comes to integrating microservices. There are two main microservices integration patterns: service orchestration (active integrations) and service choreography (reactive integration). In this session, we will delve into the implementation techniques and standards for implementing these microservice patterns and discuss how you can leverage Ballerina to realize those patterns.

1. Microservices Integration
Kasun Indrasiri
Director – Integration Architecture, WSO2
November 2018

2. Why Integrating Microservices?
○ Integration is essential to build any real world use case with cloud native
apps.
○ Microservices/cloud native applications are connected via network calls.

3. Integration in Pre-microservices Era
○ Centralized ESB layer provides integration and network communication
and governance capabilities.
Virtual
Service 1
Service A
Virtual
Service 2
Virtual
Service 3
Service B Service C Service D
ESB
Consumers

4. How to Integrate Microservices
○ Microservices code has to take care of all network communication and
governance of services
Microservice
X
Microservice
P
Microservice
Y
Microservice
z
Microservice
Q
Microservice
R
Microservice
S
Java
Consumers
Node.js Go

5. Synchronous Messaging
○ Synchronous/request-response communication
Consumer 1
API Service P API Service Q API Service R API Service S
Consumers
Consumer 2 Consumer 3
μ Service A
Proprietary
& Legacy
Systems
Web API /
SaaS
API Services/
Edge Services
Composite Service/
Integration
Services
Core Services/
Atomic Services
μ Service I
μ Service H
μ Service J
μ Service E
μ Service C
μ Service D
μ Service G
μ Service B
μ Service F
API
Management

6. Asynchronous Event-driven Communication
○ Sending message and not wait for a response
μ Service A μ Service B μ Service C
Event Bus
μ Service D
Produce Consume
Produce Consume
Produce Consume
Produce Consume

7. Catalog
Microservices Integration Use Case with Ballerina
Consumers
Checkout
REST/OpenAPI
Inventory
Shipping OderProc
Kafka
ProductInfo
REST/OpenAPI
gRPCgRPC
Ballerina Ballerina
Ballerina
Ballerina
Ballerina
Ballerina
CSV

8. Catalog
Microservices Integration Use Case with Ballerina
Consumers
Checkout
GraphQL
Inventory
Shipping OderProc
Kafka
ProductInfo
REST/OpenAPI
gRPCgRPC
Ballerina Ballerina
Ballerina
Ballerina
Ballerina
Ballerina
CSV
SFTP

9. Source Code
○ https://github.com/kasun04/microservices-integration-ballerina