A sample application to illustrate a microservice setup using Spring Cloud and Netflix OSS.
- Kotlin
- Spring Boot 2+
- Spring Cloud (Hoxton.SR8)
- Netflix OSS (Eureka, Zuul, Ribbon, Hystrix, Feign)
- Gradle
+--------------------------------------------------------------------------------------------------------------+
| | ------------------|
| Registry (Eureka) | |
| |------------ |
+--------------------------------------------------------------------------------------------------------------+ | |
| | | | |
| | | | |
| | | | |
| | | | |
| +------------------+ REST API +-----------------+ | |
| | | (with Feign) | | | |
| ---| DataSet Service |------------------------------- Vcf Service | | |
| ----/ | |-\ --/ | | | |
Incoming +-------------------+ ----/ +------------------+ ---\ Ribbon ---/ +-----------------+ | |
requests | | ----/ ---\ --/ | |
--------- | Gateway (Zuul) |-\/ --\ --/ | |
| | ---\ --/-\ | |
+-------------------+ ---\ --/ --\ | |
---\ +------------------+ ---/ ---\ +-----------------+ | |
---\ | | --/ ---\ | | | |
-- | DataSet Service |------------------------------| Vcf Service |------------+ |
| | load balancing | | |
+------------------+ +-----------------+ |
| |
| |
---------------------------------------------------------------------------------+
Application consistes of the following microservices
-
Registry (powered by Netflix Eureka) - a service registry for Service Discovery. All microservices should be registered with it.
-
Gateway (powered by Netflix Zuul) - a gateway (proxy) for external clients to interact with the application. Exposes REST endpoints of all microservices, that should be reachable from outside, in a single REST API. Performs server-side load balancing if multiple instances of a microservice is available.
-
DataSet Service - a sample microservice that provides some functionality for other microservices in the ecosystem.
-
Vcf Service - a sample microservice that acts as a client for DataSet Service, sending requests through REST. Uses:
- Feign as a REST client
- Ribbon as a client-side load balancer: reaches out to Eureka to fetch available DataSet Service's instances and queries them in a round-robin (for illustration purposes).
- Hystrix as a Circuit Breaker implementation: in case DataSet Service is not available, default logic is invocated (displaying error message in this case, but could possibly return a cached value).
- Build everything with gradle
gradlew clean build - Run Registry
java -jar registry/build/libs/registry-1.0.0.jar - Run Gateway
java -jar gateway/build/libs/gateway-1.0.0.jar - Run DataSet Service in 2 instances:
java -Dserver.port=8082 -jar dataset-service/build/libs/dataset-service-1.0.0.jar java -Dserver.port=8083 -jar dataset-service/build/libs/dataset-service-1.0.0.jar - Run Vcf Service in 2 instances:
java -Dserver.port=8080 -jar vcf-service/build/libs/vcf-service-1.0.0.jar java -Dserver.port=8081 -jar vcf-service/build/libs/vcf-service-1.0.0.jar
- Go to Eureka Dashboard: http://localhost:8761/
- Go to http://localhost:8762/actuator/routes, see
Meaning: calls to http://localhost:8762/vcf/** are forwarded to Vcf Service. DataSet Service won't be exposed to external clients.
{"/vcf/**":"vcf-service"} - Go to Gateway's endpoint http://localhost:8762/vcf/get-name refresh a couple of times. You should see:
3.1.
DATASET-SERVICEin the output 3.2.Getting DataSet Service namein logs of both Vcf Service instances 3.3.ServerListLoadBalancerlogs in logs of both Vcf Service instances 3.4.Got hit from <your IP>in logs of both DataSet Services