Spring cloud sidecar can not un-register nodeJS service once it is shut down - spring-cloud

Question

I suspect this is an issue, can anyone help to have a check?
In my sideCar application, I have application.yml:
server:
port: 5678
spring:
application:
name: nodeservice
sidecar:
port: ${nodeServer.instance.port:3000}
health-uri: http://localhost:${nodeServer.instance.port:3000}/app/health.json
eureka:
instance:
hostname: ${host.instance.name:localhost}
leaseRenewalIntervalInSeconds: 5 #default is 30, recommended to keep default
metadataMap:
instanceId: ${spring.application.name}:${spring.application.instance_id:${random.value}}
client:
serviceUrl:
defaultZone: http://localhost:8761/eureka/
And in my main spring config app, I have:
String url_node = "";
try {
InstanceInfo instance = discoveryClient.getNextServerFromEureka("nodeservice", false);
// InstanceInfo instance = discoveryClient.getNextServerFromEureka("foo", false);
url_node = instance.getHomePageUrl();
} catch (Exception e) {
}
Now I start my nodeJS server, I have in spring app:
url for nodeService is: http://SJCC02MT0NUFD58.local:3000/
This is perfect, but after I shutdown my nodeJS server,
http://localhost:3000/app/health.json url is totally down, BUT, in the main java spring app, I still see the same output there.
So it seemed even if the NodeJS service is no longer available, eureka is still remembering that in memory.
Anything wrong for my configuration?
Another question is why the url being discovered by spring is http://SJCC02MT0NUFD58.local:3000/, not http://localhost:3000? I already configured Eureka.server.instance.host to be localhost.
Thanks

Answer 1

You are seeing the appropriate behavior. Eureka and ribbon are built to be very resilient (AP in CAP). In the case you described, a service had at least one instance, then there were none, the ribbon eureka client keeps the last know list of servers around as a last resort. You're just printing the names, if you try to connect to that service it will fail. This is where you use the Hystrix Circuit Breaker that can provide a fallback in the case that no instances are up.