42. Addressing an Instance

Each instance of the application has a service ID, whose value can be set with spring.cloud.bus.id and whose value is expected to be a colon-separated list of identifiers, in order from least specific to most specific. The default value is constructed from the environment as a combination of the spring.application.name and server.port (or spring.application.index , if set). The default value of the ID is constructed in the form of app:index:id , where:

  • app is the vcap.application.name , if it exists, or spring.application.name

  • index is the vcap.application.instance_index , if it exists, spring.application.index , local.server.port , server.port , or 0 (in that order).

  • id is the vcap.application.instance_id , if it exists, or a random value.

The HTTP endpoints accept a “destination” path parameter, such as /bus-refresh/customers:9000 , where destination is a service ID. If the ID is owned by an instance on the bus, it processes the message, and all other instances ignore it.