Messages

This section explains the message related terminology to adopt ION for an application.

Messages are objects used to deliver information between applications. Each message consists of two main parts - header and content.

There are two terms ‘messages’ and ‘documents’ that can be used interchangeably most of the time.

Sometimes it is useful to know if the whole message is meant or the message content. The ‘message’ is used for complete message and ‘document’ for message content. The document can also have its own headers and content.

See the message structure in this diagram:

tr_diagram_msg_dvg

In other circumstances it is useful to differentiate between generic message definition and specific message instance. Then the ‘document’ is used for the generic definition and message for the specific instance.

In Data Fabric, all types of objects including the messages are called ‘objects’ for example in Atlas or Compass. In Data Catalog, the ‘document schema’ is called ‘object schema’. But for most purposes you can consider that to be the same thing.