CICS Introduction: Concepts and Facilities

A Short History of CICS

After providing a short overview of online systems we will explore the development of CICS from its early beginnings to its current state as a mature application server.

CICS Initialization and Termination

We will take a look at the various types of CICS startup and shutdown and will discuss their respective benefits and shortcomings.

Signing on to CICS

As CICS is usually protected by some security system, it is necessary to sign on to CICS before one can invoke any other CICS functions. We will present the CESN & CESF transactions and their various options.

Resource Definition

Before any user applications can be run under CICS, the various resources belonging to the application must be defined to CICS. We will discauus online facilities (like CEDA) as well as the batch interface (DFHCSDUP).

The Master Terminal

Every terminal known to CICS can be turned into a Master Terminal using the CEMT transaction. This provides the user with all functions needed to control CICS operations. The important components of CEMT will be presented together with a discussion of the programming interface to allow access to these functions from a CICS application.

Data Management and Recovery Facilities

Being a multiuser, multitasking application environment, CICS has to provide additional support to allow data integrity and backout facilities. We will discuss logging and locking facilities and their implications on CICS operations.

Communication Facilities

CICS provides a multi-platform environment for distributed processing of data. We will discuss the communication facilities that are built into CICS, like Transraction Routing and Function Request Shipping, and will also explain the facilities provided by Asynchronous Transaction Processing and Distributed Transaction Processing.

Client Server Facilities

To allow a complete three-tier Client/Server architecture CICS has developed into an application server as well. We will present the benefits and shortcomings of DPL (Distributed Program Link), EXCI (External CICS Interface) and RPC (Remote Procedure Call)

CICS Web Enablement

For quite some time CICS has been providing functions to allow access to CICS applications via a web browser. The various facilities like CICS Web Services, 3270 brdge etc will be discussed and demonstrated