The OTMA client

The OTMA environment includes a server and one or more clients.

This topic explains how a client interacts with the server to process IMS transactions.

What is an OTMA client?
An OTMA client is a z/OS® application program that sends transactions to an IMS server and receives output. The application program must be a member of an z/OS cross-system coupling facility (XCF) group and use the OTMA protocol.
OTMA naming conventions
The names of OTMA clients and transaction pipes must follow a convention defined by IMS.
Messages sent by OTMA clients
An OTMA client communicates with IMS by sending messages.
Sending type-1 commands from an OTMA client
You can submit type-1 IMS commands from an OTMA client application. Some restrictions and recommendations apply.
OTMA commit processing
OTMA can control how IMS commits transactions: they can be either commit-then-send or send-then-commit.
Protecting transactions with OTMA
In a z/OS environment, transaction protection and recovery is managed by z/OS Resource Recovery Services (RRS), part of z/OS Recovery Resource Management Services (RRMS). RRS can apply coordinated changes across multiple mission-critical resources.
Client/server resynchronization with OTMA
In order to guarantee that client transactions are processed and that they are processed only once, OTMA provides a protocol for synchronizing transactions.
OTMA resynchronization protocol
OTMA resynchronization is based on a series of command exchanges with each client.
Managing commit-then-send output
OTMA provides several different options for managing commit-then-send (CM0) output that is not immediately returned to hold-queue capable OTMA clients. You can purge the output, reroute the output, or share the output among multiple OTMA clients by using an OTMA super member.

Parent topic: Open Transaction Manager Access (OTMA)