title: What is instanceid in spring eureka?
body: <p>I read that instance id of Eureka Clients have to be unique and when we wish to run multiple instances of the same Eureka Client, then we add this property:</p>
  
  <pre><code>eureka.instance.instance-id==${spring.cloud.client.hostname}:${spring.application.name}:${spring.application.instance_id:${random.value}}
  </code></pre>
  
  <p>What is the significance of instance Id and how does the above line matter?</p>