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Fine tuning for VSAM dataset

 
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Vasanthr

New User


Joined: 24 Jan 2011
Posts: 21
Location: India

PostPosted: Sat Jan 17, 2015 2:24 am    Post subject: Fine tuning for VSAM dataset
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Hi Everyone,

I have a IAM file with huge number of records. I get around 200k I/O EXCP in the job log for the file in the program it is used.The program uses the file in random mode.The job takes alomst 40 -60 mins a day to complete.Could you plese provide some info how to reduce this CPU time.


Below is the file definition of the file

Code:
DEFINE CLUSTER -
  (NAME(ABC.XYZ.DATASET) -
   OWNER($IAM) -
   SHAREOPTIONS(2 3) -
   VOLUMES(* * * * * * * * * *) -
   KEYS(24 0) -
   RECSZ(0625 1250) -
   FSPC(10 10) -
   CYL(2800 2800))



IAM info report:



Code:
IAM400   INNOVATION IAM INFORMATION PRINT ROUTINE -- IAMNINFO VER 9.1/01P  -- INNOVATION DATA PROCESSING   DATE-2015.012
IAM360   STEP - STEP1   DDNAME - SYS130     DATA SET MONITORED - ABC.XYZ.DATASET
IAM361   INFO REQUESTED BY PROGRAM CARDRET   FOR INPUT PROCESSING    OPENED-2015.012.21:25:13  CLOSED-2015.012.21:47:05
IAM362   IAM DATA CHARACTERISTICS -                                                             OVERRIDES IN EFFECT:
         IAM FILE FORMAT-----------=   ENHANCED    -    IAM FILE STATUS-----------=     LOADED
         LOGICAL RECORD LENGTH-----=       1250    -    CI SIZE-------------------=       8192
         KEY SIZE------------------=         24    -    KEY OFFSET----------------=          0
         TOTAL RECORDS-------------=   65655113    -    TOTAL RECORDS DELETED-----=          8
         TOTAL RECORDS UPDATED-----=       2223    -    TOTAL RECORDS INSERTED----=       1318
IAM363   IAM FILE CHARACTERISTICS -
         BLOCKING FACTOR-----------=          4    -    BLOCK SIZE----------------=      13682
         TRACKS IN USE-------------=     208806    -    VARIABLE LENGTH OVERFLOW--=        YES
         NUMBER OF EXTENTS---------=         19    -    NUMBER OF VOLUMES---------=          4
         DATASET TYPE--------------=       KSDS    -    SHARE OPTIONS-------------=          2
         NUMBER OF IAM DATA BLOCKS-=     832630    -    HIGH ALLOCATED RBN--------=     954419
         INTEGRATED OVERFLOW (CI%)-=         10    -    DASD RESERVE (CA%)--------=         10
         FILE DEFINED DATE---------=   2015.010    -    FILE DEFINED TIME---------=   21:08:31
         FILE LOADED DATE----------=   2015.010    -    FILE LOADED TIME----------=   21:15:46
         FILE UPDATE DATE----------=   2015.012    -    FILE UPDATE TIME----------=   21:25:03
IAM372   IAM EXTENDED AREA CHARACTERISTICS -
         EXT. OVERFLOW RECORDS-----=       1196    -    EXT. OVERFLOW BLOCKS------=         10
         EXTENDED BLOCKS ALLOCATED-=     119452    -    EXTENDED PE BLOCKS--------=          0
         EXTENDED BLOCKS USED------=        256    -    EXTENDED BLOCKS AVAILABLE-=     119196
IAM365   IAM EXECUTION STATISTICS -
         TOTAL STORAGE REQUIRED----=   80658432    -    PRIME INDEX(COMPRESSED)---=   11774014
         STORAGE ABOVE THE LINE----=   80654336    -    COMPRESSED DATA STRUCTURE-=        YES
         CACHE64 STORAGE (M)-------=          0    -    TURBO BUFFERING-----------=        YES
         64-BIT INDEX STORAGE (K)--=      11712    -    TOTAL JOB 64-BIT INDEX (K)=      11712
         REQUESTS PROCESSED--------=    1425101    -    REQUESTS FAILED-----------=       1098
         DISK BLOCKS READ----------=     272382    -    DISK BLOCKS WRITTEN-------=          0
         DYNAMIC BUFFER RETRIEVALS-=     145797    -    MAXIMUM BUFFERS USED------=       4904
         MINIMUM BUFFERS USED------=         64    -    MAXIMUM BUFFERS AVAILABLE-=       4904
         DYNAMIC TABLE RETRIEVALS--=          0    -    DYNAMIC TABLE RECORDS-----=          0
IAM368   SPECIFYING A BUFNO VALUE GREATER THAN  4904 MAY IMPROVE PERFORMANCE
IAM366   IAM COMMAND EXECUTION SUMMARY -
         GET RANDOM----------------=          0    -    PUT UPDATE----------------=          0
         GET SEQUENTIAL------------=     721107    -    PUT ADD-------------------=          0
         GET PREVIOUS--------------=          0    -    POINT (START BROWSE)------=     696078
         GET KGE/GENERIC-----------=          0    -    POINT KGE/GENERIC---------=       7914
         GET (SKIP SEQUENTIAL)-----=          0    -    ERASE---------------------=          0
         ENDREQ--------------------=          0    -    WRTBFR--------------------=          0
         IAM STATISTICS------------=          0    -    IAM FLUSH BUFFER----------=          0
         CLOSE---------------------=          1    -    OPEN----------------------=          1
         CLOSE TYPE=T--------------=          0    -    VERIFY--------------------=          0
         INVALID REQUESTS----------=          0    -    RECORD LENGTH CHANGES-----=          0
         SEQ CHAINED BLOCKS READ---=      45108    -    SEQ CHAINED BLOCKS WRITTEN=          0
IAM400   INNOVATION IAM INFORMATION PRINT ROUTINE -- IAMNINFO VER 9.1/01P  -- INNOVATION DATA PROCESSING   DATE-2015.012
IAM360   STEP - STEP1  DDNAME - SYS130     DATA SET MONITORED - ABC.XYZ.DATASET
IAM361   INFO REQUESTED BY PROGRAM CARDRET   FOR INPUT PROCESSING    OPENED-2015.012.21:25:13  CLOSED-2015.012.21:47:05
IAM362   IAM DATA CHARACTERISTICS -                                                             OVERRIDES IN EFFECT:
         IAM FILE FORMAT-----------=   ENHANCED    -    IAM FILE STATUS-----------=     LOADED
         LOGICAL RECORD LENGTH-----=       1250    -    CI SIZE-------------------=       8192
         KEY SIZE------------------=         24    -    KEY OFFSET----------------=          0
         TOTAL RECORDS-------------=   65655113    -    TOTAL RECORDS DELETED-----=          8
         TOTAL RECORDS UPDATED-----=       2223    -    TOTAL RECORDS INSERTED----=       1318
IAM363   IAM FILE CHARACTERISTICS -
         BLOCKING FACTOR-----------=          4    -    BLOCK SIZE----------------=      13682
         TRACKS IN USE-------------=     208806    -    VARIABLE LENGTH OVERFLOW--=        YES
         NUMBER OF EXTENTS---------=         19    -    NUMBER OF VOLUMES---------=          4
         DATASET TYPE--------------=       KSDS    -    SHARE OPTIONS-------------=          2
         NUMBER OF IAM DATA BLOCKS-=     832630    -    HIGH ALLOCATED RBN--------=     954419
         INTEGRATED OVERFLOW (CI%)-=         10    -    DASD RESERVE (CA%)--------=         10
         FILE DEFINED DATE---------=   2015.010    -    FILE DEFINED TIME---------=   21:08:31
         FILE LOADED DATE----------=   2015.010    -    FILE LOADED TIME----------=   21:15:46
         FILE UPDATE DATE----------=   2015.012    -    FILE UPDATE TIME----------=   21:25:03
IAM372   IAM EXTENDED AREA CHARACTERISTICS -
         EXT. OVERFLOW RECORDS-----=       1196    -    EXT. OVERFLOW BLOCKS------=         10
         EXTENDED BLOCKS ALLOCATED-=     119452    -    EXTENDED PE BLOCKS--------=          0
         EXTENDED BLOCKS USED------=        256    -    EXTENDED BLOCKS AVAILABLE-=     119196
IAM365   IAM EXECUTION STATISTICS -
         TOTAL STORAGE REQUIRED----=   80658432    -    PRIME INDEX(COMPRESSED)---=   11774014
         STORAGE ABOVE THE LINE----=   80654336    -    COMPRESSED DATA STRUCTURE-=        YES
         CACHE64 STORAGE (M)-------=          0    -    TURBO BUFFERING-----------=        YES
         64-BIT INDEX STORAGE (K)--=      11712    -    TOTAL JOB 64-BIT INDEX (K)=      11712
         REQUESTS PROCESSED--------=    1425101    -    REQUESTS FAILED-----------=       1098
         DISK BLOCKS READ----------=     272382    -    DISK BLOCKS WRITTEN-------=          0
         DYNAMIC BUFFER RETRIEVALS-=     145797    -    MAXIMUM BUFFERS USED------=       4904
         MINIMUM BUFFERS USED------=         64    -    MAXIMUM BUFFERS AVAILABLE-=       4904
         DYNAMIC TABLE RETRIEVALS--=          0    -    DYNAMIC TABLE RECORDS-----=          0
IAM368   SPECIFYING A BUFNO VALUE GREATER THAN  4904 MAY IMPROVE PERFORMANCE
IAM366   IAM COMMAND EXECUTION SUMMARY -
         GET RANDOM----------------=          0    -    PUT UPDATE----------------=          0
         GET SEQUENTIAL------------=     721107    -    PUT ADD-------------------=          0
         GET PREVIOUS--------------=          0    -    POINT (START BROWSE)------=     696078
         GET KGE/GENERIC-----------=          0    -    POINT KGE/GENERIC---------=       7914
         GET (SKIP SEQUENTIAL)-----=          0    -    ERASE---------------------=          0
         ENDREQ--------------------=          0    -    WRTBFR--------------------=          0
         IAM STATISTICS------------=          0    -    IAM FLUSH BUFFER----------=          0
         CLOSE---------------------=          1    -    OPEN----------------------=          1
         CLOSE TYPE=T--------------=          0    -    VERIFY--------------------=          0
         INVALID REQUESTS----------=          0    -    RECORD LENGTH CHANGES-----=          0
         SEQ CHAINED BLOCKS READ---=      45108    -    SEQ CHAINED BLOCKS WRITTEN=          0
IAM400   INNOVATION IAM INFORMATION PRINT ROUTINE -- IAMNINFO VER 9.1/01P  -- INNOVATION DATA PROCESSING   DATE-2015.012
IAM360   STEP - STEP1   DDNAME - SYS130     DATA SET MONITORED - ABC.XYZ.DATASET
IAM361   INFO REQUESTED BY PROGRAM CARDRET   FOR INPUT PROCESSING    OPENED-2015.012.21:25:13  CLOSED-2015.012.21:47:05
IAM362   IAM DATA CHARACTERISTICS -                                                             OVERRIDES IN EFFECT:
         IAM FILE FORMAT-----------=   ENHANCED    -    IAM FILE STATUS-----------=     LOADED
         LOGICAL RECORD LENGTH-----=       1250    -    CI SIZE-------------------=       8192
         KEY SIZE------------------=         24    -    KEY OFFSET----------------=          0
         TOTAL RECORDS-------------=   65655113    -    TOTAL RECORDS DELETED-----=          8
         TOTAL RECORDS UPDATED-----=       2223    -    TOTAL RECORDS INSERTED----=       1318
IAM363   IAM FILE CHARACTERISTICS -
         BLOCKING FACTOR-----------=          4    -    BLOCK SIZE----------------=      13682
         TRACKS IN USE-------------=     208806    -    VARIABLE LENGTH OVERFLOW--=        YES
         NUMBER OF EXTENTS---------=         19    -    NUMBER OF VOLUMES---------=          4
         DATASET TYPE--------------=       KSDS    -    SHARE OPTIONS-------------=          2
         NUMBER OF IAM DATA BLOCKS-=     832630    -    HIGH ALLOCATED RBN--------=     954419
         INTEGRATED OVERFLOW (CI%)-=         10    -    DASD RESERVE (CA%)--------=         10
         FILE DEFINED DATE---------=   2015.010    -    FILE DEFINED TIME---------=   21:08:31
         FILE LOADED DATE----------=   2015.010    -    FILE LOADED TIME----------=   21:15:46
         FILE UPDATE DATE----------=   2015.012    -    FILE UPDATE TIME----------=   21:25:03
IAM372   IAM EXTENDED AREA CHARACTERISTICS -
         EXT. OVERFLOW RECORDS-----=       1196    -    EXT. OVERFLOW BLOCKS------=         10
         EXTENDED BLOCKS ALLOCATED-=     119452    -    EXTENDED PE BLOCKS--------=          0
         EXTENDED BLOCKS USED------=        256    -    EXTENDED BLOCKS AVAILABLE-=     119196
IAM365   IAM EXECUTION STATISTICS -
         TOTAL STORAGE REQUIRED----=   80658432    -    PRIME INDEX(COMPRESSED)---=   11774014
         STORAGE ABOVE THE LINE----=   80654336    -    COMPRESSED DATA STRUCTURE-=        YES
         CACHE64 STORAGE (M)-------=          0    -    TURBO BUFFERING-----------=        YES
         64-BIT INDEX STORAGE (K)--=      11712    -    TOTAL JOB 64-BIT INDEX (K)=      11712
         REQUESTS PROCESSED--------=    1425101    -    REQUESTS FAILED-----------=       1098
         DISK BLOCKS READ----------=     272382    -    DISK BLOCKS WRITTEN-------=          0
         DYNAMIC BUFFER RETRIEVALS-=     145797    -    MAXIMUM BUFFERS USED------=       4904
         MINIMUM BUFFERS USED------=         64    -    MAXIMUM BUFFERS AVAILABLE-=       4904
         DYNAMIC TABLE RETRIEVALS--=          0    -    DYNAMIC TABLE RECORDS-----=          0
IAM368   SPECIFYING A BUFNO VALUE GREATER THAN  4904 MAY IMPROVE PERFORMANCE
IAM366   IAM COMMAND EXECUTION SUMMARY -
         GET RANDOM----------------=          0    -    PUT UPDATE----------------=          0
         GET SEQUENTIAL------------=     721107    -    PUT ADD-------------------=          0
         GET PREVIOUS--------------=          0    -    POINT (START BROWSE)------=     696078
         GET KGE/GENERIC-----------=          0    -    POINT KGE/GENERIC---------=       7914
         GET (SKIP SEQUENTIAL)-----=          0    -    ERASE---------------------=          0
         ENDREQ--------------------=          0    -    WRTBFR--------------------=          0
         IAM STATISTICS------------=          0    -    IAM FLUSH BUFFER----------=          0
         CLOSE---------------------=          1    -    OPEN----------------------=          1
         CLOSE TYPE=T--------------=          0    -    VERIFY--------------------=          0
         INVALID REQUESTS----------=          0    -    RECORD LENGTH CHANGES-----=          0
         SEQ CHAINED BLOCKS READ---=      45108    -    SEQ CHAINED BLOCKS WRITTEN=          0
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Robert Sample

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Joined: 06 Jun 2008
Posts: 7912
Location: Bellevue, IA

PostPosted: Sat Jan 17, 2015 4:01 am    Post subject:
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Since this is an IAM data set and not actually a VSAM data set, you need to contact the IAM vendor and work with them on how to improve performance. For a pure VSAM data set, BLSR can help random access -- but I don't know if BLSR can even be used with an IAM data set.
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Bill Woodger

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Joined: 09 Mar 2011
Posts: 7228

PostPosted: Sat Jan 17, 2015 6:16 am    Post subject: Reply to: Fine tuning for VSAM dataset
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I'd suggest that if the program is using random, it should not. Look at the starts. Looks like skip-sequential processing. Ensure your driver-file is sorted, and don't use random. There may be other things the program is doing that it shouldn't.

I don't know IAM, but it looks like your freespace is not being utilised, but will be taking up a lot of tracks.

Robert's advice is very good.
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Pete Wilson

Active User


Joined: 31 Dec 2009
Posts: 437
Location: London

PostPosted: Thu Jan 22, 2015 6:24 pm    Post subject:
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Contacting Innovation would be a good idea, they usually respond very quickly and are usually very helpful.

It looks to me that most of the processing is sequential, only very small numbers of inserts and updates. The IAM368 message might be worth pursuing. You can add IAMOVERID DD's to the JCL when processing the file and things like buffering and other performance options can be specified there.

IAM368 SPECIFYING A BUFNO VALUE GREATER THAN 4904 MAY IMPROVE PERFORMANCE
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