Managing recovery process boost

Recovery process boosts are managed internally by z/OS, with the operating system initiating the boosts as these recovery events take place, and only on the images that are actually participating in or affected by these events. Recovery process boost periods are started and ended by Start of changeevents controlled by the z/OS operating systemEnd of change. When initiating the recovery process boost, z/OS initiates whichever boost types (speed boost, zIIP boost, or both) are identified by the BOOST= parameter in IEASYSxx currently in effect for the image. During recovery process boost periods, any available program within the boosting partition may be executed on a zIIP when zIIP boost is active.

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Dynamically enable or disable all recovery process boosts

You can dynamically enable or disable all recovery process boosts with the IEASRB proc, as follows:
  • S IEASRB,[CLASS=RP,]REQ={DISABLE|D} to dynamically disable recovery process boosts
  • S IEASRB,[CLASS=RP,]REQ={ENABLE|E} to dynamically enable recovery process boosts.

You can end an IPL or shutdown boost with the IEABE proc and start a shutdown boost with the IEASDBS proc. Start of changeFor more information, see Procs.End of change

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Control boosts for recovery events

Start of changeYou can control boosts for recovery events as follows.End of change

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  • SVC dump

    Whether or not to boost an SVC dump is determined by dump size. You set a minimum dump size threshold for boosting with the RPBMINSZ option of the CHNGDUMP SET,SDUMP command, as described below.

    Start of changeSDUMP,RPBMINSZ=nnnnn|nnnnnG|NAEnd of change
    Start of changeSpecifies the minimum estimated dump size in gigabytes for which a recovery process boost will be requested.
    • RPBMINSZ of 0 requests recovery process boost for all SVC dumps regardless of estimated dump size.
    • NA, for not applicable, means the installation does not wish to request recovery process boost for SVC dumps.
    • RPBMINSZ is not supported on either CHNGDUMP RESET or CHNGDUMP DELETE.
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    NA is the default.

    The following are examples of the CHNGDUMP command.
    • CHNGDUMP SET,SDUMP,RPBMINSZ=20G. This causes SVC dumps of 20GB or larger to be boosted.
    • CHNGDUMP SET,SDUMP,RPBMINSZ=0. This causes all SVC dumps to be boosted, regardless of size.
    • CHNGDUMP SET,SDUMP,RPBMINSZ=NA. This disables boosting of SVC dumps.

    Use the DISPLAY DUMP,OPTIONS command to view information about the settings for RPBMINSZ in message IEE857I.

    For more information, see CHNGDUMP command in z/OS MVS System Commands and Displaying dump options in z/OS MVS System Commands.

  • Middleware region startup

    Use your WLM service definition to control boosts for middleware instances that are being started or restarted. The default is that no address spaces are boosted – that is, no boosts are initiated for images on behalf of address spaces being started.

    To control boosts for middleware region start and restart, you define a classification rule for subsystem type STC, specifying a value for the Boost attribute with the Boost field on the Modify Rules for the Subsystem Type panel. The following example illustrates the process for updating the service definition with ISPF.

      Subsystem-Type  Xref  Notes  Options  Help
                    Modify Rules for the Subsystem Type        Row 1 to 5 of
    Command ===> ____________________________________________ SCROLL ===> CSR
    Subsystem Type . : STC         Fold qualifier names?   Y  (Y or N)
    Description  . . . IBM-defined subsystem type
    Action codes:  A=After    C=Copy         M=Move     I=Insert rule
                   B=Before   D=Delete row   R=Repeat   IS=Insert Sub-rule
                                                           <=== More
             -------Qualifier--------      Boost                            
    Action   Type      Name     Start                                       
     ____  1 TN        TV1*     ___        YES                              
     ____  1 TN        TV2*     ___        NO                               
     ____  1 TN        TOR      ___        YES                              
     ____  1 TN        AOR1     ___        NO                               
     ____  1 TN        AOR2     ___        NO                               
    For STC work only, you can specify the following values:
    The region does not initiate a recovery process boost when started or restarted. This is the default.
    The region initiates a recovery process boost when started or restarted.

    For all other subsystem types except STC, the Boost field is not applicable and contains N/A.

    If an address space that matches a classification rule in the active policy with Boost=YES is started or restarted, a recovery process boost is initiated that provides short-term acceleration for the process. This boost follows the same rules as recovery process boosts provided by z/OS for sysplex recovery processes.

    For more information, see Working with classification rules in z/OS MVS Planning: Workload Management.

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