eureka unknownHostException in service discovery
prranay
I have two microservices,
- eureka-client-1 running on localhost:8081
- eureka-client-2 running on localhost:8082
Both are DiscoveryClient registered with 'eureka-server' running on localhost:8761.
In the code snippet below, I am trying to call eureka-client-2 from eureka-client-1. Instead of calling http://localhost:8082 , I want to call http://eureka-client-2, but this throws a java.net.UnknownHostException during Eureka service discovery.
After searching, I found that I need to use "Brixton" to do it.
Is there a way to do this with Camden.SR3?
Please suggest.
@Component
public class HystrixDemoService {
@Bean
@LoadBalanced
public RestTemplate restTemplate() {
return new RestTemplate();
}
@HystrixCommand(fallbackMethod = "getFallbackCustomerName")
public String getCustomerName() {
RestTemplate restTemplate = new RestTemplate();
URI uri = URI.create("http://eureka-client-2"); // fails here
return restTemplate.getForObject(uri, String.class);
}
public String getFallbackCustomerName() {
System.out.println("coming inside fallback method");
return "Resillient Customer";
}
}
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.example</groupId>
<artifactId>demo-pranay-eureka-client1</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>demo-pranay-eureka-client1</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-hystrix</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Camden.SR3</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
client 1's application.properties is similar to client 2 (just change the name, e.g. eureka-client-2)
spring.application.name=eureka-client-1
server.port=8081
eureka:
client:
registerWithEureka: true
serviceUrl:
defaultZone: http://localhost:8761/eureka/
instance:
leaseRenewalIntervalInSeconds: 10
statusPageUrlPath: /info
healthCheckUrlPath: /health
application.properties for eureka server
spring.application.name=eureka-service
server.port=8761
eureka:
client:
registerWithEureka: false
serviceUrl:
defaultZone: http://localhost:8761/eureka/
instance:
leaseRenewalIntervalInSeconds: 10
statusPageUrlPath: /info
healthCheckUrlPath: /health
prranay
The changes below worked for me.
@SpringBootApplication
public class DemoPranayEurekaClient1Application {
public static void main(String[] args) {
SpringApplication.run(DemoPranayEurekaClient1Application.class, args);
}
}
@EnableDiscoveryClient
@EnableCircuitBreaker
@RestController
class HystrixDemoApplication {
@Autowired
HystrixDemoService hystrixDemoService;
@Bean
@LoadBalanced
public RestTemplate restTemplate() {
return new RestTemplate();
}
@RequestMapping("/")
public String name() {
String str = hystrixDemoService.getCustomerName();
return "I'm A talking to "+str;
}
}
Below is the line of code used to select the eureka-client-2 instance...
ServiceInstance实例= loadBalancer.choose（“ eureka-client-2”）;
@Component
public class HystrixDemoService {
@Autowired
private LoadBalancerClient loadBalancer;
@HystrixCommand(fallbackMethod = "getFallbackCustomerName")
public String getCustomerName() {
RestTemplate restTemplate = new RestTemplate();
ServiceInstance instance = loadBalancer.choose("eureka-client-2");
URI uri = instance.getUri();
return restTemplate.getForObject(uri, String.class);
}
public String getFallbackCustomerName() {
System.out.println("coming inside fallback method");
return "Resillient Customer";
}
}