Eureka never unregisters a service

Question

I'm currently facing an issue where Eureka does not unregister a registered service. I've pulled the Eureka server example straight from git hub and made only one change, eureka.enableSelfPreservation = false. My application.yml looks like this:

server:
  port: 8761
eureka:
  enableSelfPreservation: false
  client:
    registerWithEureka: false
fetchRegistry: false
  server:
    waitTimeInMsWhenSyncEmpty: 0

I've read that if 85% of the registered services stop delivering heartbeats within 15 minutes, Eureka assumes the issue is network related and does not de-register the services that are not responding. In my case I have only one service running, so I disabled self-preservation mode. I am abruptly killing the process and Eureka leaves the service registered for what seems like an indefinite amount of time.

My client's application.yml looks like this:

eureka:
  instance:
    leaseRenewalIntervalInSeconds: 3
  client:
    healthcheck:
      enabled: true
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
  appInfo:
    replicate:
      interval: 3
    initial:
      replicate:
        time: 3
spring:
  rabbitmq:
    addresses: ${vcap.services.${PREFIX:}rabbitmq.credentials.uri:amqp://${RABBITMQ_HOST:localhost}:${RABBITMQ_PORT:5672}}

My goal is to create a demo where Eureka quickly detects the service is no longer running and another service that is started can quickly register itself.

As of now, once the eureka client is started, it registers in 3 seconds. It just never un-registers when the service is abruptly terminated. After I kill the service, the Eureka dashboard reads:

EMERGENCY! EUREKA MAY BE INCORRECTLY CLAIMING INSTANCES ARE UP WHEN THEY'RE NOT. RENEWALS ARE LESSER THAN THRESHOLD AND HENCE THE INSTANCES ARE NOT BEING EXPIRED JUST TO BE SAFE.

How can I prevent this behavior?

Answer 1

I realized that self preservation mode was never actually being disabled. It turns out the actual property is

eureka.server.enableSelfPreservation=false

(See DefaultEurekaServerConfig Code), which I haven't found documented anywhere. This resolved my issue.