TECHPOD Meetup 3 - inter-service-communication-microservices

1. Inter Service
Communication in
Microservices
Ecosystem
Venugopal Gangadharan
Saravanan Patmanathan
12th Feb, 2019

2. Agenda
Blocks that build
Yes, we need to talk
Ok, But how
Talking it out
Look who is talking
Conversation control
Who is right
Can I get a visual please
Let us interact
Demo
Q & A
1

3. How deep we will dive
Overview of building blocks
Basics of different communication techniques
Pros and cons of each
Tools used for different communication styles
Illustrations
Usecase discussion
Interact with the group
Code example - One for each communication style
Q & A
1

4. Blocks that build
Multiple distributed components
Controllers
 Gateway
 Service Registry
 Configuration Service
Business
 Functional Components
Common stores
 Datastore
 Communication Bus
 Distributed Cache
2

5. Yes, we need to talk
Service dependency chaining
 Service A ---depends on---- Service B
 Service B ---depends on---- Service C
Information sharing
 Multiple services needs to know
Action Triggers
 An activity triggering a set of actions
State Update
 System with state knowledge
Order Inventory Ship
Updater State
Fault
Config
NW
Perf
Forward
Eco System
Multi-Service dependency chaining
Information sharing
NW Fault Trigger State updates

6. Ok, but how
1. Style based
 Synchronous
 Asynchronous
2. Receiver Endpoints
 Single receiver
 Multiple receivers
 Service Mesh
3. Client to Service Communication
 Direct communication to Service API
 Communication via., an API Gateway
Order Inventory Ship
Multi-Service synchronous request / response
Order Inventory
Shipment Location
sync
M M M M
T1
M
T2 T3 T4
Async

7. Talking it out
Synchronous
 Distributed with individual flow sequence
 Sequential Service Orchestration
 Parallel Service Orchestration
 Security aspects
Asynchronous
 Choreography of events
 Orchestrated sequential events
 Orchestrated Event choreography
GOSSIP
Req – wait – Resp

8. Look who is talking
Synchronous
 REST / HTTP(s)
o Spring Boot REST
 RPC
o gRPC – mono or multi lingual
o Apache Thrift
Asynchronous
 Publish / Subscribe
o Rabbit MQ
o Kafka
Orchestration
 Camunda BPM
 Activiti

9. Synchronous conversation control
User authentication &
authorization
 UAA service
Service level control
 Feign REST Client
 Declarative style
 Services control the talk
 Secure communication
 Platform level control
 Landing service availability
 Pluggable Fall back
 Hystrix based call flow

10. Conversation Control … contd.,

11. Who is right
Synchronous
 Pros
 Reliable
 Fits read heavy systems
 Consistency
 Cons
 Dependency based design
 Chained actions
 Tight Coupling
 High Possibility of cascading effects
Asynchronous
 Pros
 Greater Autonomy for Microservices
 Decouple service dependency
 Achievable scale outs
 Fits write heavy systems
 Cons:
 Complexity
 Synchronous consumers need to change

12. Can I get a visual please

13. Dance Choreography

14. Well, I control the flow

15. Lets put it together

16. Publish what ever

17. Use case: Centralized Service
Orchestration
Domain: Telecom
Use case: Network Service provisioning
Orchestration: Service type based flow
Microservices: F C A P S
Steps:
 Service data captured via., business UI
 Data translates to metadata for service provisioning
 Invokes service type based flow
 Performs flow actions via., service adapters
 Service test as part of flow

18. Use case: Event Driven Service
Orchestration
Domain: Infrastructure Management
Use case: NOC Automation
Orchestration: Customer specific Flows
Microservices: Ticketing, Escalation, Scheduler
Steps:
 Network and Enterprise connector Bridge
 Customer specific flows defined
 Events trigger the flow
 Flow triggers the microservice via., Event bus
 Actionable steps defined in event type DB
 Integration with trouble ticketing system via., Event bus

19. • https://docs.microsoft.com/en-us/dotnet/standard/microservices-
architecture
• https://dzone.com
• https://www.jhipster.tech
References please