Mainframe - Introdução CICS

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Customer Information Control System

Course Mechanics Course Type: Facilitated Course Notes: Notes are located in the Notes View. (Please see View Master/Notes Master to see the Notes View.)

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Length of Course: 40 hours. Course Audience: Team Members or Project Managers with exposure to Mainframe Technology

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Prerequisite Training

Working Knowledge on COBOL & VSAM Basic Knowledge on DB2

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Course Objectives Participants will be able to learn and work on CICS Application Programming

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AgendaIntroduction to CICS Program Preparation Program Control Basic Mapping Support Error & Exception Handling File Handling Queues Interval and Task Control Communication with Databases Recovery and restart8 January 2012 NOTE - Click on arrow to directly advance to the topic CICS.ppt 5

Customer Information Control SystemIntroduction

Introduction Whats special about CICS CICS is a growing multi-billion dollar business for customers, IBM and the thousands of software companies which support CICS CICS handles more than thirty billion transactions per day Each day CICS processes more than $1 trillion in transactions More than thirty million people use CICS CICS can support over nine hundred thousand concurrent users8 January 2012 CICS.ppt 7

Introduction Whats special about CICS (cont) CICS allows any enterprise to adopt e-business whilst minimizing the exposure to the potential risks of new technology, by use of an evolutionary approach CICS allows you to take existing applications to the web with little or no change CICS supports numerous application development environments and models including COBOL, PL/I, Java, EJB and Object Oriented (OO), in any combination

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Introduction Batch & Online - Differences BATCH SYSTEM ONLINE SYSTEM

1. Input data is prepared andgiven in sequence (file) 2. Processing sequence is predictable and hence restarting the process in case of failure is easy. 3. Programs and files cant be shared 4. Programs are scheduled through jobs8 January 2012

1. Data is entered as needednot in sequence (terminal) 2. Since processing seq. is unpredictable, special recovery/restart proc. is reqd. in case of failure. 3. Programs and files can be shared 4. Transaction can be run at any timeCICS.ppt 9

Introduction CICS Customer Information Control System - CICS developed in late 1960s as a DB/DC control system CICS provides an interface between the Operating System and application programs Macro Level CICS - initial version Assembler macro to request CICS services Command Level CICS - high level language version commands to request CICS services - Single command can replace series of macros

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Introduction

CICS & Operating System Operating System CICSEnter Code :

Users App.Prg

Files & Database

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Introduction DB/DC System Data Base Central System

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Introduction CICS System Services Data-Communication Functions Data-Handling Functions Application Program Services System Services Monitoring Functions

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Introduction Application Programming Concepts Pseudo-Conversational Multitasking Multithreading Quasi-Reentrancy

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Introduction Task A basic unit of work which is scheduled by the operating system or CICS - Read from and write to the terminal- Read and write files - Starting another task etc...

Transaction An entity which initiates execution of a task. In CICS, transaction is identified by the transaction identifier8 January 2012 CICS.ppt 15

Introduction Terminal ConversationConversationalA mode of dialogue between program and terminal based on a combination of sending message and receiving message within the same task Since human response is slower than the CPU speed, a significant amount of resource will be wasted just waiting

Pseudo-ConversationalA mode of dialogue between program and terminal which appears to the operator as a continuous conversation but which is actually carried by a series of tasks8 January 2012 CICS.ppt 16

Introduction Conversational Transaction - ExamplePROCEDURE DIVISION. : FIRST-PROCESS. EXEC CICS RECEIVE ----