HSM Internal Step RESTART Statements
This article discusses the role of Internal Step Restart statements in the HSM subsection of the VCA analyzer.
micsrm140
This article discusses the role of Internal Step Restart statements in the HSM subsection of the VCA analyzer.
RESTART
RESTART YES/NO
(Optional) Specify this value to activate internal step restart for DAILY and/or INCRccc database update job steps:
RESTART YES
If you do not specify or enable the RESTART parameter, then this option defaults to the following and internal step restart is disabled:
RESTART NO
Note:
Changing the RESTART parameter (either from NO to YES or from YES to NO) requires regeneration of the DAILY operational job by executing prefix.MICS.CNTL(JCLGEND)
or by specifying DAILY in prefix.MICS.PARMS(JCLGENU)
and executing prefix.MICS.CNTL(JCLGENU)
. If an incremental update is active for this product, also regenerate the INCRccc job.Internal step restart can significantly reduce time andresource usage to recover from daily and/or incremental update processing failures.
MICS
uses acheckpoint/restart technique.- When internal step restart is activated, the database update job step "checkpoints" (or saves) intermediate results (work file contents) and the operational environment at the end of each processing phase.
- Then, if required, the database update step can resume execution at the beginning of the processing phase in which the failure occurred.
- Restart is accomplished by restoring the operational environment from the last checkpoint, bypassing completed processing phases, and resuming execution using intermediate results (work files) from the last checkpoint.
Note:
When you activate internal step restart (RESTART YES), the following optional restart parameters are enabled. These parameters have no effect if restart is disabled (RESTART NO). For more details, see the individual parameter descriptions later in this section- RESTARTCKPT data_set_allocation_parameters
- RESTARTWORK data_set_allocation_parameters
- DYNAMWAIT minutesProcessing
Processing Phases
This product employs two database update processing phases followed by the two common roll-up phases.
- FORMAT
- Read raw input data, convert to SAS format, and output to intermediate work files.
- DBUPDATE
- Sort intermediate work file contents, eliminate duplicate input data, merge data across optional multiple work files, enhance data content, and create the new DETAIL cycle.
- DYSUM
- Summarize DETAIL data to create new DAYS cycles and to update current week-to-date and month-to-date cycles.
- DYAGE
- Cutover new database cycles to production and "age" existing cycles.
RESTART Considerations
- Overhead
- Enabling internal step restart adds some overhead to the database update job step -- the cost of taking checkpoints and managing saved materials. Since this overhead is relatively constant and independent of input data volume, you may find that costs outweigh potential savings when input data volume is low, for example in a test unit. For high volume, production units, internal step restart support overhead should be a minor portion of total resource usage.
- Cataloged Work Files
- When internal step restart is enabled, the SAS work data set, internal step restart control data set, and multiple work file data sets are allocated and cataloged with permanent dataset names so they will be retained for use in restart if the step abends. These data sets are deleted when the step completes successfully.
- Prior to enabling internal step restart support, these data sets were probably allocated on system "scratch" space with a temporary, system assigned data set names. If your installation standards do not allow "permanent" data sets on DASD volumes used for temporary work space, you may need to use the WORK, RESTARTCKPT, and RESTARTWORK parameters to direct the internal step restart data sets to a generic unit or storage class that allows cataloged data sets.
- Dynamic Allocation
- When internal step restart is active, dynamic allocation is employed for the work data sets. If your installation restricts dynamic allocation of large, cataloged data sets, you may need to use the WORK, RESTARTCKPT, and RESTARTWORK parameters to direct work data set allocation to a generic unit or storage class where dynamic allocation is allowed.
- Data Set Names
- The SAS work data set, internal step restart control data set, and multiple work file data sets are allocated and cataloged according to the standardMICSunit database data set name conventions. The default DDNAME and data set names are:
- SAS work data set//cccXWORK DD DSN=prefix.MICS.cccXWORK,.....
- Internal step restart control data set//cccXCKPT DD DSN=prefix.MICS.cccXCKPT,.....
- Multiple work file data sets//WORKnn DD DSN=prefix.MICS.cccWRKnn,.....
MICSdata sets. This minimizes data-set-name-related allocation issues. However, you can override the data set names if required. ContactBroadcom Supportfor assistance if you must change data set names.
RESTARTCKPT
This statement is optional. Specify the following to override default data set allocation parameters for the internal step restart checkpoint data set:
RESTARTCKPT data_set_allocation_parameters
Note:
RESTARTCKPT is ignored when you specify RESTART NO.The internal step restart checkpoint data set (or cccXCKPT data set) contains processing status, control, and SAS environmental information for internal step restart processing checkpoints. This includes a copy of the SAS WORK format and macro catalogs, current macro variable values, and a description of work files that may be needed to restart DAYnnn processing.
By default, the cccXCKPT data set is allocated according to the values you specified for the WORKUNIT and WORKSPACE parameters in prefix.MICS.PARMS(JCLDEF). Specify RESTARTCKPT to override this default, either to alter the space allocation or to use System Managed Storage (SMS) parameters to control data set placement and characteristics.
Note:
If you allocate insufficient space for the cccXCKPT data set, DAYnnn processing will fail and can only be restarted from the beginning.You can override the RESTARTCKPT data set allocation parameters at execution time using the //PARMOVRD facility. For more information about execution-time override of dynamic data set allocation parameters, see the Dynamic Allocation Parameter Overrides (//PARMOVRD) section.
Specify data set allocation parameters, separated by blanks, according to SAS LIBNAME statement syntax. If you need multiple lines, repeat the RESTARTCKPT keyword on the continuation line.
RESTARTCKPT accepts the engine/host options documented in the SAS Companion for the z/OS Environment, including STORCLAS, UNIT, SPACE, BLKSIZE, DATACLAS, MGMTCLAS, and VOLSER.
Do not specify the disp parameter.
Example 1:
RESTARTCKPT STORCLAS=MICSTEMP SPACE=(xxxx,(pp,ss),,,ROUND)
STORCLAS
Specifies a storage class for a new data set.
Limits:
8 characters.SPACE
Specifies how much disk space to provide for a new data set being allocated.
xxxx
TRK, CYL, or blklen
pp
The primary allocation
ss
The secondary allocation
ROUND
Specifies that the allocated space be "rounded" to a cylinder boundary when the unit specified was a block length. ROUND is ignored with the TRK or CYL options.
Example 2 (multiple lines):
RESTARTCKPT STORCLAS=MICSTEMP UNIT=SYSDA RESTARTCKPT SPACE=(xxxx,(pp,ss),,,ROUND)
STORCLAS
Specifies a storage class for a new data set.
Limits:
8 characters. UNIT
Specifies the generic unit for a new data set.
Limits:
8 characters. SPACE
Specifies how much disk space to provide for a new data set being allocated.
RESTARTWORK
This statement is optional. Specify the following to override default data set allocation parameters for the internal step restart WORK data set:
RESTARTWORK data_set_allocation_parameters
Note:
RESTARTWORK is ignored when you specify RESTART NO.The internal step restart WORK data set (or cccXWORK data set) contains the intermediate work files that are not enabled to multiple work file support, including those files you may have specified on the optional NOMULT statement.
By default, the cccXWORK data set is allocated according to the values you specified for the WORKUNIT and WORKSPACE parameters in prefix.MICS.PARMS(JCLDEF). Specify RESTARTWORK to override this default, either to alter the space allocation or to use System Managed Storage (SMS) parameters to control data set placement and characteristics.
Note:
If you allocate insufficient space for the cccXWORK data set, DAYnnn processing will fail and can only be restarted from the beginning.You can override the RESTARTCKPT data set allocation parameters at execution time using the //PARMOVRD facility. For more information about execution-time override of dynamic data set allocation parameters, see the Dynamic Allocation Parameter Overrides (//PARMOVRD) section.
Specify data set allocation parameters, separated by blanks, according to SAS LIBNAME statement syntax. If you need multiple lines, repeat the RESTARTWORK keyword on the continuation line.
RESTARTWORK accepts the engine/host options documented in "SAS Companion for the z/OS Environment", including STORCLAS, UNIT, SPACE, BLKSIZE, DATACLAS, MGMTCLAS, and VOLSER.
Do not specify the disp parameter.
Example 1:
RESTARTWORK STORCLAS=MICSTEMP SPACE=(xxxx,(pp,ss),,,ROUND)
STORCLAS
Specifies a storage class for a new data set.
Limits:
8 charactersSPACE
Specifies how much disk space to provide for a new data set being allocated.
xxxx
TRK, CYL, or blklen
pp
primary allocation
ss
secondary allocation
ROUND
Specifies that the allocated space must be "rounded" to a cylinder boundary when the unit specified was a block length. ROUND is ignored with the TRK or CYL options.
Example 2 (multiple lines):
RESTARTWORK STORCLAS=MICSTEMP UNIT=SYSDA RESTARTWORK SPACE=(xxxx,(pp,ss),,,ROUND)
STORCLAS
Specifies a storage class for a new data set
Limits:
8 characters UNIT
Specifies the generic unit for a new data set
Limits:
8 characters SPACE
Specifies how much disk space to provide for a new data set being allocated.