The basic concepts of a mainframe

What are mainframe computers? A mainframe computer is a big computer.

The basic concepts of a mainframe

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Yes, there are people who want that. JCL is easier than it might look.
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There are many other commands used when required, but they are not that frequent. Pre-requisites to start mainframe testing Basic details needed for mainframe testing are: Login ID and password for logging into the application.

Brief knowledge on ISPF commands. Names of the files, file qualifier and their types. Before starting mainframe testing, the below aspects should be verified. CLASS parameter should be pointed to the test class. Reroute the email in the job to spool or a test mail ID.

Comment the FTP steps for initial testing and then point the job to a test server. All the production libraries in the job should be changed and pointed to test libraries. The job should not be left unattended. To prevent the job to run in an infinite loop incase of any error, TIME parameter should be added with specified time.

Save the output of the job including the spool. The spool can be saved using XDC. File Create test file of needed size only. GV00 so on when necessary to store data into consecutive files with the same name. The DISP Disposition - describes the system to perform keep or delete the dataset after normal or abnormal termination of the step or job parameter for the files should be coded correctly.

Ensure that all the files used for job execution are saved and closed properly to prevent job to go into HOLD. While testing using GDGs make sure that the right version is pointed at. Database While executing the job or online program, ensure that unintended data is not inserted or updated or deleted.

Also, ensure that the correct DB2 region is used for testing. Test cases Always test for boundary conditions like — Empty file, First record processing, Last record processing, etc.

Always include both positive and negative test conditions. In case if standard procedures are used in the program like Check point restart, Abend Modules, Control files, etc. Test Data Test data setup should be done before the beginning of the testing.

Never modify the data on the test region without notifying.

The basic concepts of a mainframe

There may be other teams working with same data, and their test would fail. In case the production files are needed during the execution, proper authorization should be obtained before copying or using them.

It does not mean that the functionality is working fine.

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The job will run successfully even when the output is empty or not as per the expectation. So it is always expected to check all the outputs before declaring the job successful. It is always a good practice to do a dry run of the job under test.

Dry run is done with empty input files. This process should be followed for the jobs which are impacted by the changes made for the test cycle.

Before the test cycle begins the test job set up should be done well in advance. This will help in finding out any JCL error in advance hence saving time during execution.

Test Data availability is the primary challenge in batch testing. Required data should be created well in advance of the test cycle and should be checked for completeness. Some online transactions and batch jobs may write data into MQs Message Queue for transmitting data to other applications.

It is a good practice to check that MQs are working fine after testing. Testers should be involved in the SDLC from the requirements phase onwards.

This will help to verify if the requirements are testable. It is sometimes difficult to identify the required data from the existing – project of computer e-education with open access digital literacy movement building modern society e - learning e - inclusion open.

JCL Basic Concepts — Introduction to JCL.

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This is an introduction to IBM z/OS MVS JCL basic concepts. Yes, there are people who want that. If that’s not you, then there’s nothing to see here, move along. Typically a mainframe program refers to a file internally by a file name, or ddname, of 8 characters or less. When the program runs. About the Author.

Stuart Henderson is an experienced consultant and trainer who specializes in effective IT audits and computer security.

He has helped hundreds of organizations make better use of security software such as RACF, ACF2, and TopSecret. The Physical Oracle Architecture.

All buildings, from the home you live in to the place you work, have an architecture that keeps the building together. Jan 27,  · Mainframe Introduction -Mainframe Cobol Tutorial Part 1 Tutorial shows the basic information about what is mainframe . Apr 06,  · Basic Concepts of Job Control Language JCL - Tutorial 01 Q.

What is a Job? A. Mainframe computers are used to process data. They perform tasks or operations on the data, to generate valuable information as Output. A job is a set of tasks performed on input data, to produce output results.

IBM Mainframes: Basic Concepts of Job Control Language JCL - Tutorial 01