Eureka Peer awareness example not working

Question

I am facing problem while running Eureka server example to understand peer awareness concept. I have following Eureka service:

package com.micro.eurekaserver;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@SpringBootApplication
@EnableDiscoveryClient
@EnableEurekaServer
public class EurekaServerMicroServiceApplication {

    public static void main(String[] args) {
        SpringApplication.run(EurekaServerMicroServiceApplication.class, args);
    }
}

application.yml

 ---
spring:
  profiles: peer1
server:
  port: 8761
eureka:
  instance:
    hostname: peer1
  client:
    serviceUrl:
      defaultZone: http://peer2:8762/eureka/

---
spring:
  profiles: peer2
server:
  port: 8762
eureka:
  instance:
    hostname: peer2
  client:
    serviceUrl:
      defaultZone: http://peer1:8761/eureka/

bootstrap.yml

spring:
  application:
    name: eureka

etc/hosts

127.0.0.1   peer1
127.0.0.1   peer2
localhost   peer1
localhost   peer2

When I am running this Eureka service, I am continuously getting following exception:

2016-03-26 12:19:57.708 ERROR 4940 --- [ main]

com.netflix.discovery.DiscoveryClient    : Can't contact any eureka nodes - possibly a security group issue?

com.sun.jersey.api.client.ClientHandlerException: java.net.ConnectException: Connection refused: connect
    at com.sun.jersey.client.apache4.ApacheHttpClient4Handler.handle(ApacheHttpClient4Handler.java:187) ~[jersey-apache-client4-1.19.jar:1.19]
    at com.sun.jersey.api.client.filter.GZIPContentEncodingFilter.handle(GZIPContentEncodingFilter.java:123) ~[jersey-client-1.19.jar:1.19]
    at com.netflix.discovery.EurekaIdentityHeaderFilter.handle(EurekaIdentityHeaderFilter.java:27) ~[eureka-client-1.3.7.jar:1.3.7]
    at com.sun.jersey.api.client.Client.handle(Client.java:652) ~[jersey-client-1.19.jar:1.19]
    at com.sun.jersey.api.client.WebResource.handle(WebResource.java:682) ~[jersey-client-1.19.jar:1.19]
    at com.sun.jersey.api.client.WebResource.access$200(WebResource.java:74) ~[jersey-client-1.19.jar:1.19]
    at com.sun.jersey.api.client.WebResource$Builder.get(WebResource.java:509) ~[jersey-client-1.19.jar:1.19]
    at com.netflix.discovery.DiscoveryClient.getUrl(DiscoveryClient.java:1802) [eureka-client-1.3.7.jar:1.3.7]
    at com.netflix.discovery.DiscoveryClient.makeRemoteCall(DiscoveryClient.java:1546) [eureka-client-1.3.7.jar:1.3.7]
    at com.netflix.discovery.DiscoveryClient.makeRemoteCallWithFollowRedirect(DiscoveryClient.java:1460) [eureka-client-1.3.7.jar:1.3.7]
    at com.netflix.discovery.DiscoveryClient.makeRemoteCall(DiscoveryClient.java:1443) [eureka-client-1.3.7.jar:1.3.7]
    at com.netflix.discovery.DiscoveryClient.makeRemoteCall(DiscoveryClient.java:1394) [eureka-client-1.3.7.jar:1.3.7]

2016-03-26 12:23:09.963 ERROR 4940 --- [tbeatExecutor-0] com.netflix.discovery.DiscoveryClient    : DiscoveryClient_EUREKA/KHUJEMA-PC:eureka - was unable to send heartbeat!

com.sun.jersey.api.client.ClientHandlerException: java.net.ConnectException: Connection refused: connect
    at com.sun.jersey.client.apache4.ApacheHttpClient4Handler.handle(ApacheHttpClient4Handler.java:187) ~[jersey-apache-client4-1.19.jar:1.19]
    at com.sun.jersey.api.client.filter.GZIPContentEncodingFilter.handle(GZIPContentEncodingFilter.java:123) ~[jersey-client-1.19.jar:1.19]
    at com.netflix.discovery.EurekaIdentityHeaderFilter.handle(EurekaIdentityHeaderFilter.java:27) ~[eureka-client-1.3.7.jar:1.3.7]
    at com.sun.jersey.api.client.Client.handle(Client.java:652) ~[jersey-client-1.19.jar:1.19]
    at com.sun.jersey.api.client.WebResource.handle(WebResource.java:682) ~[jersey-client-1.19.jar:1.19]

I am successfully able to run Eureka service with single instance. I am only facing issues for two instances. Following demo example from github: [ https://github.com/rcapraro/spring-cloud-sample][1]

What I also noticed in logs is tomcat embeded server is getting started on port-8080 instead of 8761/8762, not sure why?

Please help!

Answer 1

Try removing the @EnableDiscoveryClient from your Application.java. Mine looks like this:

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@SpringBootApplication
@EnableEurekaServer
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

Answer 2

If Eureka is still starting on 8080 most-likely you are not passing the active Spring profile.

Each instance would need to be started as:

java -Dspring.profiles.active=peer1 target/<artifact>.jar

and

java -Dspring.profiles.active=peer2 target/<artifact>.jar

BTW, I would suggest to start instances in a different way, I don't think this scales very well, what if you need to start a 3rd instance? With this setup you probably need to modify application.yml to add a 3rd profile, see the issue?

I recently blogged about Microservices Registration and Discovery using Spring Cloud Eureka Ribbon and Feign where I covered running Eureka in standalone and peerAware modes using Spring profiles. In the peerAware profile, I pass the location of the other Eureka instances using a VM argument, so no need to change the code to start new instances. It also covers load-balancing requests using Feign , Ribbon and RestTemplate and the clients are implemented using Jersey 1 and Spring REST.

Answer 3

I had the same issue,searched a lot with no luck!

Finally, I just modified profiles to profile, it surprisingly worked:

spring:
  profile: peer1

Rather than:

spring:
   profiles: peer1