Introduction to the IBM Application Development Tools on z/OS and OS/390

348 IBM Application Development Tools for z/OS and OS/390

10.1 Scenarios overview

We have one application which has been written to demonstrate the features of

the Application Development Tools. It is the Trader stock trading application. The

users of this application might be investors checking their holdings, or buying and

selling shares of stock. The application takes two forms:

򐂰 CICS transaction

򐂰 Batch job

Each form can access data on VSAM, DB2 or IMS/DB, also known as DL/I.

In the chapters that follow, we create scenarios based on the Trader application.

In each scenario, we deliberately introduce errors into the application to allow us

to demonstrate the functionality of the tools. We then describe, in detail, the

steps that you take to isolate the error and to correct the problem.

10.1.1 Overview of the programs

The Trader application is used to maintain a stock portfolio held by an individual.

This application enables you to:

򐂰 Obtain quotes (in batch mode, you list portfolios and their values)

򐂰 Buy more shares of a company’s stock

򐂰 Sell currently held shares of a company’s stock

The Trader application uses two data sources:

򐂰 Company data

򐂰 Customer data

The company source contains the stock name and the past week’s quotes. The

customer source contains a record for each customer and company that he or

she owns, including the number of shares held.

It can be two VSAM files, two DB2 tables in the MYTRADD DB2 plan, or two IMS

DB PSB.

In the CICS application, the transaction input is taken directly from an online

user’s interactions. In the batch application, the user’s input is replaced with a

sequential file that contains several records that represent the day’s transactions.

Note: his application does not reflect real-world securities processing.It is

merely designed to demonstrate the features of the Application Development

Too l s.

Chapter 10. Introduction to the scenarios 349

Overview of the CICS program

Figure 10-1 shows the processing that occurs in the CICS application.

Figure 10-1 Trader application: single user transaction with CICS

Overview of the batch program

Figure 10-2 shows the processing that occurs in the batch application.

Note: When you invoke this application, you can use any user name and

password. But, if you want to see the status from previous trading, use the

same user name each time.

MYTRADM

MYTRADS

Customer

Company

VSAM file VSAM file

CICS application with VSAM files

350 IBM Application Development Tools for z/OS and OS/390

Figure 10-2 Trader application: multiple remote site transactions with batch

10.1.2 S/390 software prerequisites

The application programs listed in Table 10-1 were created for this redbook and

are installed on our system. These application programs were designed to

demonstrate the functionality of the Application Development Tools.

Table 10-1 Application programs used in Trader application

Note: You should always list the holdings of a user name to determine the

number of shares in a portfolio before you begin to trade with it.

TRADERB

Customer

Company

VSAM file VSAM file

Batch application with VSAM files

Tranfile

Site A

Site B

Site C

Application program Subsystem Purpose

MYTRADMV

MYTRADS

CICS To retrieve customer information from

VSAM files

TRADERB Batch To process customer transactions from

sequential and VSAM files

MYTRADMD

MYTRADD

CICS and DB2 To retrieve customer information from

DB2 tables

TRADERD Batch and DB2 To process customer transactions from

sequential file and DB2 tables