Patterns of asynchronous requests

Typically, there are three cases where an application issues requests in parallel to multiple, external services, and requires a response.

Response is required from all
Response is required from any
Response is required from a specific target

In CICS® asynchronous transaction processing, the requestor is called the PARENT. The target is called a CHILD.

In these illustrations, the program parent, PROGP, issues three children: PROGC1, PROGC2, and PROGC3 to fetch data, and the PROGP waits for a response.

Waiting for responses from all children

In this illustration, the parent waits for responses from all the children. image shows the parent waiting for all the children to return responses.

Waiting for responses from any children

In this illustration, the parent waits for responses from any of the children. image shows the parent waiting for any of the children to return responses.

Waiting for responses from a specific child

In this illustration, the parent waits for the response from one specific child. image shows the parent waiting for a specific child to return its response.