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VSAM to DB2 MIGRATIONBusiness Reasons
&Technical Solution Overview
Thomas Beyer Brian Lee Dave Dando
Lightyear Consulting Ltd. 1-877-LIGHTYR
L I G H T Y E A R
VSAM to DB2 Migration - Agenda• BUSINESS ISSUES FOR VSAM to DB2 MIGRATION
• Who are Lightyear Consulting and Circle Computer ?
• VS2 OVERVIEW
• MIGRATION PROCESS OVERVIEW
• DB2 TABLE DESIGN + MAPPING / DATA MIGRATION
• SW INSTALLATION and SUPPORT
• POST-MIGRATION APPLICATION MAINTENANCE
• RUN TIME CONSIDERATIONS
2
Lightyear Consulting Ltd.
• formed 1991 in W-Canada, expansion into USA in 1996• IBM BESTeam Partner• IBM Beacon Award Winner in 1999• Winner of Best IBM OS/390 SW Distributor in 2000• Skilled in and certified by IBM in IMS, DB2, CICS and OS/390 (z/OS),
WEBSPHERE, VISUALAGE FOR JAVA• Education, Consulting, Software Development• Offices in Calgary, Palo Alto, Los Angeles, Phoenix, Austin• signed distributor agreement for DL/2 and VS2 specifically to address customers that have stated their intent/desire to move off IMS and/or VSAM without re-write• in-house consultants and external contractor network for VSAM, IMS, DB2, JAVA, WebSphere or DL/2 specific skills and/or project management, incl. IBM CERTIFIED DB2, WEBSPHERE, CICS, VISUALAGE FOR JAVA
L I G H T Y E A R
3a
CIRCLE COMPUTER GROUP
• FORMED IN 1978
• SW Manufacturer of DL/2 and VS2
• SKILLS ORIENTED and TECHNICAL FOCUS
• EDUCATION, CONSULTANCY, SOFTWARE
• US OFFICE - mainly for CICS/DB2 Education
• S/W Distributors in USA, Scandinavia, Germany, Italy, France, Japan, South America, Israel, Australia
• IBM BEST Team Partner
• Ownership of all CICS courses run by IBM world wide
3b
Moving from VSAM to DB2 - Options
3
O P T I O N 1 M i g r a t e V S A M a p p l i c a t i o n s a n d d a t a s e t s t o D B 2 e n v i r o n m e n t
Unrea l i s t i c cos t , r i sky e f for t , unreachable goa l s cons ider ing evo lv ing bus ines s pr ior i t i e s
O P T I O N 2 P e r f o r m e x t r a c t s a n d q u e r i e s d i r e c t l y o n V S A M d a t a s e t s
E x p e n s i v e , t i m e c o n s u m i n g , f r u s trat ing , non -f l ex ib l e for 24x7 or rea l t ime purposes , l ack o f too l s and sk i l l s .
O P T I O N 3 D u p l i c a t e V S A M d a t a s e t s t o D B 2
Forever dup l i c i ty , ongo ing da ta c l eans ing , s y n c h r o n i z a t i o n / r e s t r u c t u r i n g b e c o m e s m a j o r r e s o u r c e t a x , n o r e a l t i m e o r 2 4 x 7 benef i t s , d a y o l d d a t a s y n d r o m e
O P T I O N 4 M i g r a t e o n l y t h e d a t a a n d i t s a c c e s s t o D B 2
V S 2
B o t h q u i c k e s t a n d m o s t r e l i a b l e , s o u r c e c o d e r e m a i n s u n c h a n g e d , r e m o v a l o f V S A M d e p e n d e n c i e s , m i g r a t i o n r i s k m i n i m i z e d , qua l i ty o f da ta and SLA's , p l en ty o f t oo l s , a c c e p t a b l e p e r f o r m a n c e t a x , r e a l t i m e d a t a ava i lab le a t a l l t imes to a l l cus tomers ( s ing le s o u r c e o f d a t a ) , Y o u r c o m p a n y a n d I B M ' s s tra teg ic d irec t ion across a l l p la t forms .
VS2 - What are the Benefits (1) ?
Conventional Migration Effort From VSAM To DB2
Analysis Re -programming effort Testing
Analysis VS2 Testing
VSAM To DB2 using VS2
• SIGNIFICANT RISK ELIMINATION AND COST REDUCTION• Application code is unchanged• Application functionality is not compromised• Dataset by Dataset migration - phased-in approach• Use VSAM and DB2 concurrently during migration• Use of modern relational approaches to write new programs (ODBC, JDBC, SQL, Java, tools, …) and change data structures• Relational skills (both DBA and programming) readily available in
marketplace 4a
VS2 - What are the Benefits (2) ?
4b
A c k n o w l e d g e d S t r e n g t h s • V S 2 c o m e s f r o m t h e s a m e s t a b l e a s D L / 2 w h i c h i s a s o l i d p r o d u c t
b e i n g e x p l o r e d b y n u m e r o u s L e g a c y o r g a n i z a t i o n s w o r l d w i d e , w i t h a c o m p r e h e n s i v e s u p p o r t s y s t e m a l r e a d y i n p l a c e .
• V S 2 p r o v i d e s L e g a c y d a t a i n D B 2 f o r m f o r a n a l y s i s , q u e r y , e - p u r p o s e . • P r e s e r v i n g t h e i n v e s t m e n t i n a p p l i c a t i o n L e g a c y c o d e , i . e . , a p p l i c a t i o n s
k e e p r u n n i n g u n c h a n g e d , V S 2 t r a n s p a r e n t l y r e d i r e c t s d a t a s e t c a l l s t o e i t h e r V S A M o r D B 2 w h i c h e v e r i s a p p r o p r i a t e .
• N o s o u r c e c o d e c h a n g e s a r e r e q u i r e d f o r t h e c o n v e r s i o n . • N e w a p p l i c a t i o n d e v e l o p m e n t c a n b e 1 0 0 % D B 2 b a s e d . • V a r i o u s l e v e l s o f c o n v e r s i o n a r e a v a i l a b l e i . e . , F r o m b a s i c K e y a n d D a t a
t h r o u g h a f u l l y f u n c t i o n i n g D B 2 d a t a b a s e . B u s i n e s s r e q u i r e m e n t a n d a v a i l a b l e r e s o u r c e d e t e r m i n e c o n v e r s i o n l e v e l s . M i x i n g a n d m a t c h i n g o f a v a i l a b l e o p t i o n s i s a l s o a v a i l a b l e .
• D u r i n g m a i n t e n a n c e , a p p l i c a t i o n s c a n b e o p t i m i z e d f o r D B 2 a s a n d w h e n
r e s o u r c e s b e c o m e a v a i l a b l e o r b u s i n e s s i m p e r a t i v e s d i c t a t e s o . • M i n i m u m r i s k m i g r a t i o n , a t c u s t o m e r ' s p a c e o n a d a t a s e t b y d a t a s e t b a s i s .
T h i s g r a d u a l p r o c e s s a l l o w s f o r d a t a c l e a n s i n g a n d e a s e o f a u d i t a b i l i t y p r o c e d u r e s .
• V S A M d a t a s t r u c t u r e s a r e r e - e n g i n e e r e d t o D B 2 m o d e i n e i t h e r o f t h e s e
w a y s :
V S A M d a t a s e t D B 2 d a t a b a s e O n e R e c o r d O n e T a b l e R e c o m m e n d e d D e s i g n O n e R e c o r d S e v e r a l T ab l e s ( u p t o 5 ) U s e r E x i t s R e q u i r e d S e v e r a l R e c o r d s O n e T a b l e U s e r E x i t s R e q u i r e d
VS2 - What are the Benefits (3) ?
4c
Additional Benefits • Organizations can refocus on growing its business and technical
capabilities under a single data infrastructure paradigm ♦ Potential for faster deployment of new applications or application
upgrades ♦ Single source of production data, available at all times to all
customers alike ♦ Consistent quality-of-data and quality-of-service across the board
to all customers • Simplifies data maintainability and future database restructuring • Effective assistance toward the Continuous Availability and Real
Time needs for 24x7 purposes • Significant economy-of-scale savings are possible in certain
elements: ♦ CPU and DASD usage, DRP complexity ♦ Application and Data maintainability ♦ Reduced set of production and development OEM tools
• Facilitates the running of Sysplex environments
♦ Provides simplification to the Real Time Operability challenges ♦ Allows for better management of standards and measurements ♦ Simpler set-up and operation of test streams
• Harmonizing potential
♦ Planning, Development and Service Delivery resources/Skills ♦ Change Management and Control processes
Immediate Gains • Removal of long-existing VSAM dataset
limitations
♦ Not necessary to evaluate and acquire more VSAM scaffolding features.
• DB2 already includes a sound and established
Partition Tablespace feature
♦ No logical storage limitations • All related business data can be moved quickly
into one single type of database
♦ Most organizations have a mixed set of VSAM datasets and DB2 databases
è VS2 will allow for a clearly-defined, recognized, supported data architecture direction
When should you NOT migrate off VSAM
• If you have a heavy dependency on features that are not supported with VS2 (see chart near end of presentation)
• If you have no DB2 in-house and no intention to acquire it• If you envision increased usage/investment into new VSAM
applications• If you have written extensive non-VSAM applications interfacing
into VSAM via the Operating system
5
• ISPF MAPPING/GENERATION FACILITY> Map VSAM fields to DB2 Columns> Generate VS2 driver programs
• CALL INTERCEPTION FACILITY> Intercepts VSAM calls and directs them to VS2 for
processing
• VS2 MAPPER
• SAMPLE COBOL, PL/1 AND ASSEMBLER EXITS SUPPLIED
VSAM COMPONENTS
6
DB2 Database DesignDB2 Database Design
Write/test exits
LOAD DB2
MIGRATION PROCESS OVERVIEW
• REQUIRES APPL KNOWLEDGE AND VS2 SKILL
MAP
TEST TEST
REMAP
PROTOTYPEPROTOTYPE• MIGRATION BY File or File group
7
AnalysisAnalysis
Test Appls
Appl Prog
VSAM
VSAM call
EXECUTION PROCESS FLOW - 1
BEFORE VS2 AFTER VS2 - PART 1 OF 2
VSAM record
Appl Prog
VSAM
SUBSYS=CIRSon ‘DD’
NO
DB2
YES
VSAM call
8
EXECUTION PROCESS FLOW - 2
FOLLOWING CONVERSION TO VS2 - PART 2 OF 2
Appl Prog
VIDMAIN SQL Driver
DB2
VSAM call
DB2 I/O Area
FBE IRD
APPLICATION I/O AREA
9
VS2 generatedstatic SQL driver
VS2 EXITS
PHYSICAL DB2 DATABASE DESIGN
• ONE DB2 TABLE FOR EVERY VSAM file set (Base, AIX, Path)
• VSAM BASE CLUSTER KEY BECOMES DB2 PRIMARY KEY
• COPYBOOK FIELD BECOMES DB2 COLUMN (typically) • REDEFINED RECORD LAYOUTS HANDLED THROUGH EXITS
• OBSOLETE (Filler ?) FIELDS DO NOT NEED TO BE MIGRATED TO DB2
10
VS2 MAPPING
VSAM RECORD
Base Key Index 1 Index 2
DB2 I/O AREA
• FIELD to COLUMN Relationship using VSAM Copybook
• Mapping performed through VS2 ISPF Dialogues or by VS2 MAPPER
• ONE TIME ACTIVITY
C1 C2 C3 C4 C5 C6 C7 C8
11
MAPPING PROCESS
12
1. CREATE DB2 DATABASE
2. MAP RECORDS
3. GENERATE SQL DRIVERS
4 UNLOAD DATA FROM VSAM (VS2 utility)
5. CONVERT UNLOAD FILE AND LOAD DB2 TABLES
6 IN BATCH - JCL changeIN CICS - Add file to VS2 Table (Macro driven
7. TEST> MAPPING> EXITS Test Applications
RE-ENGINEERING
• VSAM PICTURE FIELDS ==> DB2 DATE> Typically 4 byte packed field X’0971229C’ becomes 1997-12-29
• OBSOLETE FIELDS
> Omit from DB2 Table (Fields defined as ‘FILLER’)
• MOVING FIELD POSITION
• CHANGING FIELD ATTRIBUTES > Extending field size> Numeric fields to DECIMAL, INTEGERER, SMALLINT
• ADDING ADDITIONAL COLUMNS> For future use by ‘new’ DB2 applications
13
• COPYBOOK REDEFINES
• PROBLEM VSAM allows differing data types in the same record structure Handled by applications using masks.
• RESOLUTION VS2 provides granularity through Exits and additional DB2 tables
RE-ENGINEERING
ADDITIONAL RE-ENGINEERING THROUGH FBE & IRD EXITS
14
REDEFINED RECORD
15
LAYOUT=A
LAYOUT=B
LAYOUT=C
XCOMMON AREA
DB2TAB_COMMON KCOL_A, KCOL_B + Common area columnsDB2TAB_LAYOUT_A KCOL_A, KCOL_B + Layout=A columnsDB2TAB_LAYOUT_B KCOL_A, KCOL_B + Layout=B columnsDB2TAB_LAYOUT_C KCOL_A, KCOL_B + Layout=C columns
1. FIELD BUILD EXIT TO READ APPROPRIATE TABLE BASEDFIELD BUILD EXIT TO READ APPROPRIATE TABLE BASEDON FIELD XON FIELD X2. IRD EXIT REQUIRED FOR UPDATE PROCESSING BASED ONIRD EXIT REQUIRED FOR UPDATE PROCESSING BASED ONFIELD XFIELD X
OTHER POTENTIAL SOLUTIONS
VSAM RECORD
USER FIELD BUILD EXIT - POSSIBLE USE
• TO ENRICH DB2 DATA
Name Town City
DB2 Record Layout
VSAM record
National Phone
• MANY OTHER POSSIBILITIES
Street Ctry
Name Town City InternationalPhone
Street Country name
Flag resolved by Appl pgm
Translated by FBE
nn
Mapped
to
16
BIND LINK
SQL DRIVER GENERATION
STAGE I STAGE ll
VS2 job
VS2
Prog logic;--EXEC SQL;--END EXEC;-End;
VID_SRC
Precompile
DBRM ASSEMBLE
17
- Mapping tables
RUN-TIME CONSIDERATIONS
• VSAM APPLICATIONS NOW BECOME DB2 APPLICATIONS > Housekeeping Utilities in DB2> Local and Disaster Recovery Implications
• PACKAGE BIND / EXPLAIN
• DB2 PERFORMANCE / CAPACITY IMPLICATIONS
• CHANGES TO DB2 APPLICATION ENVIRONMENT> VS2 Drivers May need to be Re-Genned
18
POST-MIGRATION APPL MAINTENANCE
• APPLICATION CHANGES CAN BE SQL-BASED> New SQL calls can be Added to Application Programs> Existing VSAM calls can be changed
19
INSTALLING VS2
• UNIQUE ‘RIGHT TO USE’ KEY FOR EACH CPU EXTENDED ANNUALLY
• ISPF TAILORING APPLICATION> Customised INSTALL AND SAMPLIB libraries
• VS2 LOAD LIBRARY and DRIVERS LIBRARY;> LPALIB in Batch - Subsystem> DFHRPL in CICS> LPA changes
• BATCH JCL CHANGES FOR ACCESS TO DB2
• OPTIONALLY> Enable supplied Trace and Debugging Facilities
• FIXES DELIVERED BY EMAIL - USUALLY AMASPZAP FORMAT
20
FEATURES NOT SUPPORTED
• VSAM ESDS Datasets
• VSAM LDS Datasets
• RBA Processing
21
Next Steps:
• Follow-up on some technical issues
• Pilot porting project to assess validity (billable)
• Mentoring/training onsite or at Lightyear’s or Circle’s offices
• Development of a migration project
23
Upcoming Lightyear Events• October 21 to 25 - DB2 (and CICS + IMS) City-to-City Roadshow - hosted by IBM and Lightyear
(with Lightyear and IBM speakers)– pick a 1/2 day or a full day agenda– Oct. 21- Seattle– Oct. 22 - Pasadena / Los Angeles– Oct. 23 - Phoenix, AZ– Oct. 24 - Dallas, TX– Oct. 25 - Kansas City, MO– register now !
• November 6: z/OS Update - What new beyond OS/390• November 19 or 20: IMS to DB2 Conversion without application re-write• December or early next year: DB2 Stored procedures - What Options do you have ?• Early Next year: Wireless Access to Legacy Data - Options• Early Next year or later this year: Application Construction with WebSphere Studio Application
Developer (aka VisualAge for Java Vnext) and/or Host-on-Demand - what is a better option ?• Details at: www.lightyr.com - you will get an e-mail invite once details are finalized !
