How to Use XINFO in a “Rightsize” Project

Information is a prerequisite for any conversion. That’s why any substantial conversion project begins with an analysis of the current status. This usually involves SMF reports, which take a long time to run, to dump all information, REXX programs to analyze job libraries and so on. This raw information is then collated into compact and easy-to-read lists of important details. 

This document is not a "cookbook" with detailed instructions but is meant to give you an idea of the powerful functions of XINFO. All the examples given here require knowledge of XINFO tables, the ISPF dialog or the PC client. Please use the XINFO manuals or contact HORIZONT at mailto:info@horizont-it.com for further information. 

• Which jobs are obsolete?

• How much disk space is required by production jobs?

• Which DB2 tables are used by which production jobs?

• How is the actual production defined in the JSS (Job Scheduling System)?

• And after migration you throw XINFO away?

The BATCH command allows you to create a batch job that will run any query in batch mode. This function is normally used to generate lists automatically but it also has an additional advantage: The "simple" SQL generated by XINFO's ISPF dialog can be modified easily. 

By using the information from the TABLES command, a "sub-select" can be performed to obtain the desired jobs: 

SELECT JOBJN,… FROM XINFO30.XXRTJOB WHERE JOBJN NOT IN (SELECT SMFJOBNAME FROM XINFO30.XXRVSMJ WHERE SMFSTARTTS >= '2003-01-01-00.00.00') 

The result is a list of all the jobs (in the job libraries) that have not been used in the last year. 

The next example shows you how to create a list of jobs that are not defined in the scheduler. Unlike in the previous example, we are now using the XINFO PC client. The PC client is based on the same principles as the ISPF client: A panel allows you to specify selection criteria and the results are displayed in a table. As with the ISPF dialog, the standard panels of the PC client are not sufficient for all questions. For more complicated queries, the SQL must be modified manually. 

1. The "JCL job statement" table and the "TWS job definition" table are the basic input, but you need a "SQL sub-select" to answer the question.

2. Use the SQL menu button in the "JCL – Job Statements" display to get the SQL. Please note that this option can be used to get the table and column names of all XINFO objects: The SELECT window shows all columns, the FROM window shows the table names.

3. Modify the WHERE clause
   WHERE JOBJN NOT IN (SELECT ADROPJN FROM XINFO30.XXRTOP)

4. The resulting list shows all the jobs found in job libraries but not defined in the scheduler (in our example OPC, but also possible for all other schedulers). 

Please note that the same result is also available using XINFO's ISPF dialog (see previous example). 

Before performing a migration, it is necessary to determine the space required for all files on the new platform. XINFO's space scanner helps you by creating overviews of all (or selected) volumes or files. 

As shown in the previous examples, the volume and file information can be linked to information in other tables, for example:

• How much space is required by jobs that are defined in the scheduler?

• How much space is allocated but unused?

• How many files are on tape?

• How many files have been migrated, and how much space is used by these files?

If XINFO's integrated statistics function is not sufficient for your needs, you can also export tables easily to other programs. The XINFO PC client exports to HTML, XML, CSV (EXCEL) and many more formats.

Before a performing a migration it is essential to get an overview of the complexity of the database used by production jobs. Typical standard sources such as JCL or DB2 catalogs do not answer questions such as:

• How many tables are used by applications ABC*?

• How many views are defined for tables XYZ*?

• How many jobs are doing DB reorgs?

XINFO’s source analyzers and DB2 scanners help you to create the reports you need.

XINFO produces diagrams illustrating the job streams planned in the scheduler. During migration these XINFO outputs can be used as a ready method to quickly gauge the quality of the conversion. No one can read and absorb all the information in a long written list but a glance at the conversion result diagram will tell you whether something has been overlooked or not.

A gradual transition poses the problem of identifying conversion packages and residual dependencies, that is, identifying groups of jobs that are relatively well integrated and that have few outside dependencies between jobs already converted and those that have not yet been converted.

There is a myth that prevails in our industry: “The next conversion will be the last one.”

The next conversion is probably in sight or just around the corner. Whatever your next big conversion is, it’ll involve finding out about current jobs, programs, databases, files and their complex relationships and then modifying them.

XINFO is continually being developed: It now has a new distributed architecture. And TWS, UC4, script scanners, SAP interfaces and much more are under development or available now.

But if you’re sure you won’t need XINFO anymore (because you’re migrating to pure online systems or to a platform not supported by XINFO), there are other ways of taking advantage of its benefits: You can rent XINFO at a reasonable price. Just ask us. We’ll be happy to answer any of your questions: mailto:info@Horizont-it.com.