The synchronous callout function for IMS
This document provides the associated requirements, installation, technical approaches, and monitoring and troubleshooting information or pointers to this information for the synchronous callout function that is made available in IMS™ Version 11 and later.
IMS application programs running in IMS dependent regions can send outbound messages to request services or data, such as from a web service, a message-driven bean (MDB), or an Enterprise JavaBeans™ (EJB) component, and receive responses in the same transaction during the same unit of work through IMS Connect and OTMA. The request for services or data outside of the IMS installation is a callout request.
For synchronous callout requests, an IMS application program that runs in an IMS dependent region issues an IMS call (the DL/I ICAL call) and waits in the dependent region to process the response. When the ICAL call is issued, IMS generates a correlation token for synchronous callout requests. This correlation token is included with the callout request and must be returned to IMS with the response to route the response back to the requesting IMS application program.
You can issue a callout request from an IMS application and synchronously receive the response by using any of the following approaches:
- IMS Enterprise Suite Version SOAP Gateway
SOAP Gateway enables IMS applications to inter operate outside of the IMS environment through SOAP to provide and request services independent of platforms, environments, application languages, or programming models. For IMS synchronous callout requests, SOAP Gateway handles the correlation of requests and responses for you.
- IMS TM Resource Adapter Version
The IMS TM resource adapter enables you to easily create Java™ applications that access new and existing IMS transactions over the Internet, or process IMS callout requests to services or data over the Internet. IMS TM Resource Adapter Version 11.1 or later is required.
- Your own IMS Connect TCP/IP client applications
You can write your own IMS Connect TCP/IP client applications or use a vendor-supplied solution that uses TCP/IP and the IMS Connect protocol to retrieve callout requests. For example, you can use the IMS Enterprise Suite Connect API for Java to implement a synchronous callout interaction.
Your custom IMS Connect client application must issue a RESUME TPIPE call to an OTMA routing destination,also known as a transaction pipe (or tpipe), that is defined in an OTMA destination descriptor. This transaction pipe holds the callout requests. Your custom IMS Connect TCP/IP client application must poll the tpipe to retrieve the callout requests.
The IMS synchronous callout function is available in IMS Version 11 or later. For IMS Version 11, the Installation Verification Program (IVP) support to demonstrate the function in IMS Version 11 does require application of additional APARs.
APAR requirements for IMS Version 11
|PK97597||UK61338||IMS IVP support for the callout function|
|PK85023||UK48124||Java support for the DL/I ICAL call|
|PM29392||UK64387||Synchronous and asynchronous callout IVP sample for IMS TM resource adapter|
|PM31226||UK68815||Synchronous and asynchronous callout IVP sample for IMS Enterprise Suite SOAP Gateway|
Important: JBP and JMP support for issuing callout requests requires the JMS interface classes. Download the IMS Enterprise Suite JMS API from the IMS Enterprise Suite website.
Synchronous callout documentation
The following table lists where you can find more information about the synchronous callout function for IMS 14, IMS 13, and IMS 12.
|General steps to implement the synchronous callout function||
|The new DL/I ICAL call||IMS 14:
|IMS Connect support for synchronous callout messages|
|OTMA support for synchronous callout messages|
|IMS Enterprise Suite SOAP Gateway support for the synchronous callout function||
IMS Enterprise Suite SOAP Gateway: Enabling an IMS application as a web service consumer
|IMS TM resource adapter support for the synchronous callout function||
IMS TM Resource Adapter: Callout programming models
IMS Enterprise Suite Connect API for Java support for the synchronous callout function
IMS Enterprise Suite Connect API for Java: Implementing a synchronous callout interaction with the Connect API for Java
|Callout samples IVP||
IMS Version 14 Installation:
IMS Version 13 Installation:
IMS Version 12 Installation: