PQ55553: PERFORMANCE IMPROVEMENT BY DEFAULT OPTION CHANGE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Default values of PIPEDEPTH for pipes should be increased
  for better performance.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IPR Driver of IMS Parallel      *
  *                 Reorganization for z/OS Version 2            *
  *                 (FMID=H25N210).                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: Performance of IPR Driver can be        *
  *                      degraded when the default pipe depth    *
  *                      values are used.                        *
  ****************************************************************
  * RECOMMENDATION: Apply the maintenance for this APAR.         *
  ****************************************************************
  Performance of IPR Driver can be degraded when the default pipe
  depth values are used. Depths of the pipe between Unload task
  and Reload task and the pipe between Reload task and Index
  Builder task should be increased for better performance; and,
  the undocumented control statements for IPRPIPE should be
  documented so that users can increase or decrease the pipe block
  size (PIPEBLKSZ) and the pipe depth (PIPEDEPTH).
  

Problem conclusion

• The default pipe depth for each pipe has been increased from
  2 to 62.
  *
  *======================*
  * DOCUMENTATION CHANGE *
  *======================*
  The following documentation change should be made to
  IMS Parallel Reorganization for z/OS Version 2 User's Guide
  ( SC27118000 ).  The changes are marked by a vertical bar (|).
  *
  Chapter 2. IMS Parallel Reorganization Driver
  2.7 Control Statements
  2.7.2 Control Statements for Reorganization Manager
  *
    The control statement block for Reorganization Manager starts
    with a line that specifies the block name REORG. In the REORG
    block, you can specify the following control statements:
     ____________________________________________________________
    | Table 2. Control Statements for Reorganization Manager     |
    |__________ ___________________ _________ ___________________|
    | Keyword  | Acceptable Values | Default | Description       |
    |__________|___________________|_________|___________________|
    |          |                   |         |                   |
                         :
                         :
                         :
    |__________|___________________|_________|___________________|
  | |PIPEBLKSZ |(a,b)              |(32768,1)|Specifies how many |
  | |          |                   |and      |records to move to |
  | |          |a=1024-65536,      |(32768,2)|and from the pipe  |
  | |          |b=1 or 2           |         |at one time. See   |
  | |          |                   |         |"PIPEBLKSZ Control |
  | |          |                   |         |Statement."        |
  | |__________|___________________|_________|___________________|
  | |PIPEDEPTH |(a,b)              |(62,1)   |Specifies the      |
  | |          |                   |and      |number of blocks   |
  | |          |a=2-32767,         |(62,2)   |that can be in the |
  | |          |b=1 or 2           |         |pipe at any given  |
  | |          |                   |         |time before the    |
  | |          |                   |         |pipe becomes full. |
  | |          |                   |         |See "PIPEDEPTH     |
  | |          |                   |         |Control Statement."|
  | |__________|___________________|_________|___________________|
  | |PIPEWAIT  |(a,b)              |(15,1)   |Specifies the      |
  | |          |                   |and      |amount of time a   |
  | |          |a=1-1441,          |(15,2)   |writer or reader   |
  | |          |b=1 or 2           |         |of a pipe can      |
  | |          |                   |         |remain in a wait   |
  | |          |                   |         |state before IPR   |
  | |          |                   |         |Driver issues a    |
  | |          |                   |         |message and gets   |
  | |          |                   |         |to abend.  See     |
  | |          |                   |         |"PIPEWAIT Control  |
  | |          |                   |         |Statement."        |
  | |__________|___________________|_________|___________________|
  *
  2.7.6 Description of Control Statements for Reorganization
        Manager
            ...
    2.7.6.9 NEWDBD Control Statement
            ...
  | 2.7.6.10 PIPEBLKSZ Control Statement
  | PIPEBLKSZ specifies how many records to move to and from a
  | pipe at one time.
  |
  | The block size specified in PIPEBLKSZ must include the data
  | length (up to 32,756 bytes) plus 4 bytes required for the
  | internal block descriptor word (BDW).
  |
  | If you make a change to the PIPEBLKSZ specification, you might
  | need to change the value of the REGION parameter to avoid
  | running out of virtual storage.
  |
  | >>__PIPEBLKSZ=_ _(_blksize_,_pipeID_)_ _________><
  |                |                      |
  |                |_______blksize________|
  |
  | The first parameter blksize specifies the block size for the
  | pipe identified by pipeID. The second parameter pipeID
  | specifies the pipe ID of a pipe to which the control statement
  | applies.  See "Note on pipe ID" for the valid pipe IDs.
  | If only the blksize value is specified, it applies to the pipe
  | of pipe ID 1.
  |
  | The default block size is 32768 for each pipe. The maximum
  | value is 65536, and the minimum value is 1024. The minimum
  | value must be larger than or equal to the maximum length of
  | records you are to transfer through the pipe plus four.
  |
  | Note on pipe ID: Pipe ID is a number that identifies a pipe
  | allocated between tasks running in a Parallel Reorganization
  | job. The following pipes are allocated:
  |  - A pipe between the Unload task and the Reload task.
  |    This pipe is always allocated and has pipe ID 1.
  |  - A pipe between the Reload task and the Index Builder task.
  |    This pipe is allocated only when INDEXBLD=YES is specified
  |    and has pipe ID 2.
  |
  | 2.7.6.11 PIPEDEPTH Control Statement
  | PIPEDEPTH specifies the number of blocks that can be in a
  | pipe at any given time before the pipe becomes "full."
  |
  | The use of large values for PIPEDEPTH enables IPR Driver
  | to accumulate more information in virtual storage. This can be
  | helpful in smoothing out periodic wait periods where the
  | writing task is forced to wait because the pipe temporarily
  | becomes full because the reading task is temporarily delayed
  | in reading data from the pipe.
  |
  | If you make a change to the PIPEDEPTH specification, you might
  | need to change the value of the REGION parameter to avoid
  | running out of virtual storage.
  |
  | >>__PIPEDEPTH=_ _(_depth_,_pipeID_)_ _________><
  |                |                    |
  |                |_______depth________|
  |
  | The first parameter depth specifies the number of blocks that
  | can be held in the pipe, which is identified by the second
  | parameter pipeID, at any given time before the pipe becomes
  | "full." See "Note on pipe ID" for the valid pipe IDs. If only
  | the depth value is specified, it applies to the pipe of pipe
  | ID 1.
  |
  | depth can be a value from 2 to 32767. The default value is 62
  | for each pipe.
  |
  | 2.7.6.12 PIPEWAIT Control Statement
  | PIPEWAIT specifies the amount of time a writer or reader of a
  | pipe can remain in a wait state before IPR Driver issues a
  | message and gets to abend.
  |
  | >>__PIPEWAIT=_ _(_time_,_pipeID_)_ _________><
  |               |                   |
  |               |_______time________|
  |
  | The first parameter time indicates the number of minutes,
  | ranging from 1 to 1440, that a writer or reader of the pipe
  | identified by the second parameter pipeID can remain in a wait
  | state. See "Note on pipe ID" for the valid pipe IDs. If only
  | the time value is specified, it applies to the pipe of pipe
  | ID 1.
  |
  | The default setting of time value is 15 for each pipe.
  *
  Appendix E. Messages and Codes
  E.3 Messages
  E.3.4 HPSG Messages
  >>> The following message is modified. <<<
    HPSG0212E  n-th OPERAND MUST BE text
    Explanation: The n-th operand of the control statement must be
    specified as indicated by the string text. Text is one of the
    following:
         EITHER YES OR NO
         EITHER ON OR OFF
         EITHER WTOR OR ABORT
         EITHER CURRENT OR NEW
  |      A NUMBER BETWEEN 2 AND 32767, BOTH INCLUSIVE
         A NUMBER BETWEEN 1024 AND 65536, BOTH INCLUSIVE
         A NUMBER BETWEEN 1 AND 1440, BOTH INCLUSIVE
         A VALID DSNAME QUALIFIER OTHER THAN T
         OMITTED WHEN DYNALLOC IS NO FOR OUTPUT DATA SETS
         OMITTED WHEN INDEXBLD=NO
     System Action:  IPR Driver ends with a return code of 8.
     Programmer Response:  Correct the control statement as
     indicated by the message, and rerun the job.
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UQ61446

Modules/Macros

• HPSGCM00 HPSGGIOB HPSGGIO0 HPSGSTMT
  

Fix information

• Fixed component name

  IMS PARALLEL RE

• Fixed component ID

  5655F7400

Applicable component levels

• R210 PSY UQ61446

     UP01/12/24 P F112 Ž

Fix is available

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