The Receiving Layer

This layer deals with polling various locations to determine if new records, files or incoming requests exist. The various locations include:

• Staging tables, including XAI staging control, XAI upload staging, notification download staging (certain products only), and outbound message.
• An external directory that contains a file, for example a comma delimited file or an XML file.
• A JMS queue/topic.

A separate receiver is defined to read requests from each of these locations. When the MPL server starts, it looks for all defined active receivers in the XAI Receiver table, and for each receiver it starts a thread that constantly fetches messages from the message source.

Once a request message is read, it is passed to an execution thread that implements the execution layer. Each receiver references an Executer that is responsible for executing the request.