vmptk / rsocket-load-balancing

RSocket load balancing demo

RSocket Load Balancing with Spring Cloud Registry

RSocket load balance based on Spring Cloud Service Registry.

How to run?

• Start Consul first： docker-compose up -d consul or consul agent -dev ，then open http://localhost:8500
• Start server-app: mvn -pl server-app spring-boot:run
• Start client-app: mvn -pl client-app spring-boot:run
• Test your RSocket service invocation： curl http://localhost:9080/square/3

App & Service interface naming specification

Spring Cloud Service Registry uses spring.application.name as service name on registry server, and appName is the serviceId argument in ReactiveDiscoveryClient.getInstances(String serviceId);

For example, we have a service app with two service interfaces: MathCalculatorService and ExchangeCalculatorService.
Please use Java package naming style to name your app, such as com-example-calculator. Service interface naming should follow String serviceName = appName.replace("-", ".") + "." + interfaceName; rule, example as following:

• com.example.calculator.MathCalculatorService
• com.example.calculator.ExchangeCalculatorService

If you use RSocket Broker to proxy the requests, and you should use broker: as prefix for service name, such as broker:com.example.calculator.ExchangeCalculatorService, and broker is the RSocket Broker's name, and you can use ReactiveDiscoveryClient.getInstances(appName) to query broker instance list.

Why this naming style? Take a look at the following steps to call remote RSocket services:

• Extract appName from service full name. For example, appName is com-example-calculator from com.example.calculator.MathCalculatorService
• Invoke ReactiveDiscoveryClient.getInstances(appName) to get app instance list
• Build RSocketRequester with load balance support with RSocketRequester.Builder.transports(servers)
• Call RSocketRequester api with service full name as routing key

 rsocketRequester.route("com.example.calculator.MathCalculatorService.square")
                .data(number)
                .retrieveMono(Integer.class)

This naming style is easy for RSocket to interact with service registry and RSocket service routing.

If you can not inline the appName in service's full name, and you can use appName as schema style for service invocation,
such as calculator-server:com.example.calculator.math.MathCalculatorService. With this way,
and it's easy to migrate other applications into RSocket RPC design.

References

• YMNNALFT: Easy RPC with RSocket: https://spring.io/blog/2021/01/18/ymnnalft-easy-rpc-with-rsocket
• Spring Cloud Consul: https://docs.spring.io/spring-cloud-consul/docs/current/reference/html/
• Spring Retrosocket: https://github.com/spring-projects-experimental/spring-retrosocket
• RSocket Load Balancing: https://www.vinsguru.com/rsocket-load-balancing-client-side/