Asynchronous Interactions with a Notification Timer

In this chapter, we will learn about asynchronous interactions with a notification timer. Consider the following points related to the asynchronous interactions −

• The Client BPEL Process sends a request to the Service BPEL Process and waits for a reply, although a notification is sent after a timer expires.

• The Client BPEL Process continues to wait for the reply from the Service BPEL Process even after the timer has expired.

• The Client BPEL Process needs a scope activity containing an invoke activity to send the request, and a receive activity to accept the reply. The onAlarm handler of the scope activity has a time limit and instructions on what to do when the timer expires.

• For example, wait 60 seconds, then send a warning indicating that the process is taking longer than expected.

• The Service BPEL Process needs a receive activity to accept the incoming request and an invoke activity to return either the requested information or a fault.

• As with all partner activities, the Web Services Description Language (WSDL) file defines the interaction.