IBM Information Management System (IMS) - Group home

Introducing the new IMS Connect send-only with error protocol!

By Sanjay Kaliyur posted Mon August 01, 2022 04:31 PM


By Bill Huynh and Sanjay Kaliyur

IMS is a very stable and reliable product. We take pride in IMS’s ability to stay up and to keep your critical business applications running. But in those moments when IMS may not be behaving in the way that your business needs it to, it’s important that we enable you to be resilient. Today, we’re excited to announce a new feature that will better enable you to keep your IMS systems running smoothly: The IMS Connect send-only with error protocol. 

A new version of the IMS Connect send-only protocol

The IMS Connect send-only with error protocol is very closely related to the existing IMS Connect send-only protocol. Client applications use the IMS Connect send-only protocol to send commit mode 0 (CM0), a.k.a. commit-then-send, transactions to IMS in rapid succession without requiring the client application to wait for a response. The send-only protocol is designed for fast, high-volume input. However, any error that occurs in IMS Connect or IMS is not returned to the client. Without error responses, diagnosing these errors is challenging.

 Making IMS Connect more diagnosable and resilient

This new send-only with error protocol will help IMS customers diagnose potential errors while still maintaining the high-throughput characteristic of the send-only protocol. When using this new protocol and an error is detected in IMS Connect, IMS Connect will now return an error code back to the client. Receiving an error code when a transaction fails to go through is very important for diagnosing issues and addressing them as soon as they pop up. Note that for both this new protocol and the existing send-only protocol, if an error is detected in IMS, IMS Connect will not report that error back to the client.

How do I use this new protocol?

The send-only with error protocol is supported for the HWSSMPL0 and HWSSMPL1 user message exits. The client specifies to use the send-only with error protocol by setting the IRM_F4 field to the character ‘J’ (IRM_F4_SNDONLYE) in the IRM of the transaction input message.

When the client application uses send-only with error protocol, it should use one thread to continuously send transactions on the socket connection to IMS Connect and a secondary thread that monitors potential error responses on the same socket connection. If IMS Connect returns an error response, the socket connection will be closed. When that occurs, the client will have to open a new socket connection to continue sending transactions.

How can I get it?

The new IMS Connect send-only with error protocol is available for all IMS customers running IMS version 15.1 and above through APAR PH41890.

If you’d like to learn more about IMS and view the great educational content our team has made available, please visit IMS Central.