Wednesday, June 3, 2020

Spring cloud service discovery example

Real time cloud application consist of a large number of micro services communicating with each other. Service instances are added/removed dynamically based on requirement and availability. Service discovery is the process of one service dynamically discovering the network location (IP address and port) of another service without hard coding their location.


Steps involved in service discovery

1. Service registers location - when service boots up it registers itself with discovery server

2. Client looks for service location - When client needs to hit a particular service first it goes to discover server for its location

3. Discovery server sends back location - Discovery server sends the active location of the particular service

4. Client request service at location - This is a normal request to the service

5. Service sends response - Service responds to client accordingly

Example -

Started eureka server on default port 8761 and Started 2 instances of Application service on 8081 and 8082




Discovery Server

pom.xml
application.properties
DiscoveryServerApplication.java

Application Service

pom.xml
application.properties
ServiceApplication.java
Controller.java

Client

pom.xml
application.properties
DiscoveryClientApplication.java
Controller.java

Here is complete source code in Github

https://github.com/madan712/discovery-server

https://github.com/madan712/discovery-application-service

https://github.com/madan712/discovery-client