DiscoveryClient does not see a service from Eureka

Question

When I ask eureka about the services it knows (localhost:8071/eureka/apps/), it says 3 are UP:

<applications>
  <versions__delta>1</versions__delta>
  <apps__hashcode>UP_3_</apps__hashcode>
  <application>
    <name>ROUTER</name>
    <instance>
      <instanceId>localhost:router:8765</instanceId>
      <hostName>localhost</hostName>
      <app>ROUTER</app>
      <ipAddr>10.0.75.1</ipAddr>
      <status>UP</status>
      <overriddenstatus>UNKNOWN</overriddenstatus>
      <port enabled="true">8765</port>
      <securePort enabled="false">443</securePort>
      <countryId>1</countryId>
      <dataCenterInfo class="com.netflix.appinfo.InstanceInfo$DefaultDataCenterInfo">
        <name>MyOwn</name>
      </dataCenterInfo>
      <leaseInfo>
        <renewalIntervalInSecs>30</renewalIntervalInSecs>
        <durationInSecs>90</durationInSecs>
        <registrationTimestamp>1502197927458</registrationTimestamp>
        <lastRenewalTimestamp>1502198527594</lastRenewalTimestamp>
        <evictionTimestamp>0</evictionTimestamp>
        <serviceUpTimestamp>1502197927458</serviceUpTimestamp>
      </leaseInfo>
      <metadata class="java.util.Collections$EmptyMap"/>
      <homePageUrl>http://localhost:8765/</homePageUrl>
      <statusPageUrl>http://localhost:8765/info</statusPageUrl>
      <healthCheckUrl>http://localhost:8765/health</healthCheckUrl>
      <vipAddress>router</vipAddress>
      <secureVipAddress>router</secureVipAddress>
      <isCoordinatingDiscoveryServer>false</isCoordinatingDiscoveryServer>
      <lastUpdatedTimestamp>1502197927458</lastUpdatedTimestamp>
      <lastDirtyTimestamp>1502197825173</lastDirtyTimestamp>
      <actionType>ADDED</actionType>
    </instance>
  </application>
  <application>
    <name>ORDERS</name>
    <instance>
      <instanceId>localhost:ORDERS:8081</instanceId>
      <hostName>localhost</hostName>
      <app>ORDERS</app>
      <ipAddr>10.0.75.1</ipAddr>
      <status>UP</status>
      <overriddenstatus>UNKNOWN</overriddenstatus>
      <port enabled="true">8081</port>
      <securePort enabled="false">443</securePort>
      <countryId>1</countryId>
      <dataCenterInfo class="com.netflix.appinfo.InstanceInfo$DefaultDataCenterInfo">
        <name>MyOwn</name>
      </dataCenterInfo>
      <leaseInfo>
        <renewalIntervalInSecs>30</renewalIntervalInSecs>
        <durationInSecs>90</durationInSecs>
        <registrationTimestamp>1502198168983</registrationTimestamp>
        <lastRenewalTimestamp>1502198528945</lastRenewalTimestamp>
        <evictionTimestamp>0</evictionTimestamp>
        <serviceUpTimestamp>1502198088982</serviceUpTimestamp>
      </leaseInfo>
      <metadata class="java.util.Collections$EmptyMap"/>
      <homePageUrl>http://localhost:8081/</homePageUrl>
      <statusPageUrl>http://localhost:8081/info</statusPageUrl>
      <healthCheckUrl>http://localhost:8081/health</healthCheckUrl>
      <vipAddress>ORDERS</vipAddress>
      <secureVipAddress>ORDERS</secureVipAddress>
      <isCoordinatingDiscoveryServer>false</isCoordinatingDiscoveryServer>
      <lastUpdatedTimestamp>1502198168983</lastUpdatedTimestamp>
      <lastDirtyTimestamp>1502198168956</lastDirtyTimestamp>
      <actionType>ADDED</actionType>
    </instance>
  </application>
  <application>
    <name>FRONTEND</name>
    <instance>
      <instanceId>32e1ed7e75ba:8080</instanceId>
      <hostName>32e1ed7e75ba</hostName>
      <app>FRONTEND</app>
      <ipAddr>172.17.0.3</ipAddr>
      <status>UP</status>
      <overriddenstatus>UNKNOWN</overriddenstatus>
      <port enabled="true">8080</port>
      <securePort enabled="false">7002</securePort>
      <countryId>1</countryId>
      <dataCenterInfo class="com.netflix.appinfo.InstanceInfo$DefaultDataCenterInfo">
        <name>MyOwn</name>
      </dataCenterInfo>
      <leaseInfo>
        <renewalIntervalInSecs>30</renewalIntervalInSecs>
        <durationInSecs>90</durationInSecs>
        <registrationTimestamp>1502197928887</registrationTimestamp>
        <lastRenewalTimestamp>1502198529372</lastRenewalTimestamp>
        <evictionTimestamp>0</evictionTimestamp>
        <serviceUpTimestamp>1502197928887</serviceUpTimestamp>
      </leaseInfo>
      <metadata class="java.util.Collections$EmptyMap"/>
      <homePageUrl>http://32e1ed7e75ba:8080</homePageUrl>
      <statusPageUrl>http://32e1ed7e75ba:8080/info</statusPageUrl>
      <healthCheckUrl>http://32e1ed7e75ba:8080/health</healthCheckUrl>
      <vipAddress>true</vipAddress>
      <isCoordinatingDiscoveryServer>false</isCoordinatingDiscoveryServer>
      <lastUpdatedTimestamp>1502197928887</lastUpdatedTimestamp>
      <lastDirtyTimestamp>1502197928886</lastDirtyTimestamp>
      <actionType>ADDED</actionType>
    </instance>
  </application>
</applications>

But then I ask my ROUTER, which ones does it know (using the ServiceInstanceRestController from https://spring.io/guides/gs/service-registration-and-discovery/) it says 2 - ROUTER and ORDER, but no FRONTEND.

Do anyone know what might be the reason?

Just as a hint, the WEBFRONT app is a nodejs app with eureka plugin. Both ROUTER and ORDERS are Boots. Apparently FRONTEND registers correctly and eureka sees it as UP. I compared the eureka XML output line by line for ORDERS and FRONTEND and do not see really any critical difference...

Answer 1

One thing I found is the frontend service's vipAddress field which is true, but I think it should be FRONTEND or frontend in your case. Because under the hood EurekaDiscoveryClient uses com.netflix.discovery.EurekaClient getInstancesByVipAddress(String,bool) function (source in the spring-cloud-netflix-eureka-client project) which queries the available services by their vipAddress.

After the change you should see the service in the response of your router service's /service-instances/frontend path.