COBOL V5 Migration Strategies

COBOL V5 Migration Strategies17033

Jim Liebert, CompuwareInsert

Custom

Session

QR if

Desired.

34/14/2015

Wednesday

16710: COBOL V5 User Experience

Background

COBOL 5 Migration – Share Seattle 2015

44/14/2015

IBM

Tuesday

16615: How to Take Advantage of the New COBOL V5

Compiler – Migration!Overview

Friday

16710: COBOL V5 Migration Strategy

Case Study

Wednesday

16710: COBOL V5 User Experience

COBOL V5: CliffsNotes

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• Significant rewrite by IBM

- leverage Code Generator code used in Java and C/C++- catch up with z/OS hardware improvements- (more or less) compatible with previous COBOL compilers- (more or less) can run combined with older COBOL executables

• Performance improvements- YMMV. We see 5-7% at our customers (highs in the 9-11% range)- IBM says up to 20% in certain cases.

COBOL V5Win-Win

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For consumers

- possible budget savings

- software catches up to hardware

- IBM commitment

For IBM

- common code paths

- reinvigorate a significant money maker

- growth path

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Risk

Reward

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Risk

Reward

COBOL 5 Project

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Risk

Reward

COBOL 5 Migration

Effort

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Risk

Reward

COBOL 5 Migration

Effort

DevOps: How much time to

implement a one line coding

change?

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Wednesday

16710: COBOL V5 User Experience

Migration

First Steps

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1. Read the Book!

GC14-7383-03

First Steps

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1. Read Migration Guide

2. Create a project!

a) Scope

b) Effort

c) Expectations

1

2

3

4

Migration Project

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1

2

3

4

Project Milestones

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preliminary

work

organic

changes

aggressive

changesfinal

checkpoint

1 2 3 4

Project Timeline

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Time

3IBM grace period for running two COBOL versions¹

¹ talk with IBM

Preliminary Work

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• Simplify migration by completing these items beforehand

• Do not order COBOL v5 until you’re happy with the preliminary work!

1

Preliminary Work

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1

a Get current

Preliminary Work

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1

a Get current

b Complete LE runtime migration

Preliminary Work

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1

a Get current

b Complete LE runtime migration

bc Convert Load libraries to PDSE

Preliminary Work

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1

a Get current

b Complete LE runtime migration

bc Convert Load libraries to PDSE

d SCM product to drive all compiles

Preliminary Work

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1

e Order and install COBOL v5¹

¹ Likely to involve many PTF’s – don’t forget ISV’s too.

Preliminary Work

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1

e

f Implement COBOL v5 in SCM driven compiles

• JCL changes• decide on certain compile options

• AFP• ARCH• HGPR• OPT• SSRANGE• STGOPT

Order and install COBOL v5

1 2 3 4

Project Timeline

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Time

3

Organic changes

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2

a Pilot project

Organic changes

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2

a Pilot project

b Migrate programs as they come up for changes.

• Bug fixes

• Active development

• How much added regression testing?

Organic changes

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2

a Pilot project

b Migrate programs as they come up for changes.

• Bug fixes

• Active development

• How much added regression testing?

bc Publish results• CPU savings• % complete (total, by application)

Organic changes

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Challenges

• Expect “devil is in the details” type problems at this point.

• Exception criteria?

• When to move to step 3? What about code freeze?

2

b

1 2 3 4

Project Timeline

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Time

3

Aggressive changes

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• Identify HIGH CPU consumers or direct effect on your R4HA

• High volume CICS transactions or DB2 stored procedures.

• Long running batch jobs

• Decide how aggressive to address these changes.

• Publish results! (particularly $$$ savings)

• Consider migrating entire applications

3

1 2 3 4

Project Timeline

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Time

3

Final checkpoint

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• Confident of conversion effort – willing to retire the older COBOL

• Go through one code freeze cycle?

4

1 2 3 4

Project Timeline

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Time

3

Project Analysis

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• Did the project meet expectations?

• CPU savings

• $ savings

• effort

• What about the remaining COBOL programs?

5

Project by Group

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SCM Admin

Systems Applications

Project by Group

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SCM Admin

Systems Applications1. Compile JCL

2. Compile optionsa) At each promotion level

3. No-go gates

Project by Group

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SCM Admin

Systems Applications

1. LE Conversion

2. PDSE conversion

3. Currency

Project by Group

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SCM Admin

Systems Applications

1. Application Migration

2. Regression testing

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Wednesday

16710: COBOL V5 User Experience

Considerations

Compile Options

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Option Consideration

OPT(n) Recommend OPT(0) during development; OPT(2) for last compile

SSRANGE Can no longer be deactivated at run time

ARCH Lowest common denominator;DR considerations

Older Environments

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Environment Consideration

OS/VS COBOL Doesn’t mix with COBOL 5

VS COBOL II If NORES – cannot mix with COBOL 5

Storage Eye-catchers May be removed (STGOPT)

AMODE(24) Part of migration – to remove this restriction?

Abend Personality

424/14/2015

Index over-runs:

• May change from S0C7 to S0C4

• Over-run itself may corrupt / re-corrupt / un-corrupt index

- Removes forensics

- Applications may reach out to systems to help solve

4/14/2015 43

Questions?

4/14/2015 44

THANK YOU