Introducing dynamic parallel invocations

In this section, we introduce a new sample named book querying process that reads a book name as input, searches it across all the bookstores (Bookstore A, Bookstore B, and Bookstore C), and returns the bookstores in which the book is available. The sample is as shown in the following screenshot:

Creating the <forEach> activity

Let's move on to the creation of the <forEach> activity creation. Within the <forEach> activity, we use the <invoke> activity to send search requests. During the <invoke> creation process, the input and output variable creation also can be configured. First of all, let's create a new asynchronous BPEL 2.0 process named Book_Querying_Process. We illustrated creating an asynchronous BPEL process in Chapter 5, Interaction Patterns in BPEL.