Statements/parameters for IEAOPTxx

ABNORMALTERM=option

Specifies if the abnormal terminations, that are reported by the WLM report service IWMRPT for a server, are included when computing the weight of the routing service IWM4SRSC that is called for the server. The syntax is:

ABNORMALTERM=NO means that the abnormal terminations, that are reported by the IWMRPT service, are not included when computing the weight of the IWM4SRSC routing service. ABNORMALTERM=YES means that the abnormal terminations are included when computing the weight of the IWM4SRSC routing service.

Values: YES or NO

Default Value: YES

BLWLINTHD=option

Specifies the threshold time interval for which a blocked address space or enclave must wait before being considered for promotion.

If the CPU utilization of a system is at 100%, workloads with low importance (low dispatch priority) might not get dispatched anymore. This can lead to problems if the low priority work holds a resource that is required by high priority workloads. Therefore, if an address space or enclave has ready-to-run work units (TCBs or SRBs) but does not get CPU service for the specified time interval because of its low dispatch priority, it will be temporarily promoted to a higher dispatch priority. Address spaces that are swapped out are not considered for promotion.

Value range: Start of change

1-65535 seconds End of change

Default Value: 20 seconds

BLWLTRPCT=option

Specifies how much of the CPU capacity is to be used to promote blocked workloads. This parameter does not influence the amount of CPU service that a single blocked address space or enclave is given. Instead, this parameter influences how many different address spaces or enclaves can be promoted at the same point in time. If the value specified with this parameter is not large enough, blocked workloads might need to wait longer than the time interval defined by BLWLINTHD.

Value Range: 0-200 (up to 20%. 0% indicates blocked workload support is not enabled.)

Default Value: 5 (0.5%)

CCCAWMT=xxxxxxx

Specifies whether to activate or deactivate Alternate Wait Management (AWM). If AWM is active, SRM and LPAR cooperate to reduce low utilization effects and overhead. In an LPAR, some n-way environments with little work appear to require more capacity than expected because of the time spent waking up idle logical and physical processors to compete for individual pieces of work. If AWM is active, SRM and LPAR will reduce this unproductive use of processor so that capacity planning is more accurate and CPU overhead is reduced.

Value Range: For HIPERDISPATCH=NO, any value between 1 and 499999 makes AWM active, and any value between 500000 and 1000000 makes AWM inactive. AWM is active or inactive only for general CPs, zAAPs, and zIIPs.

For HIPERDISPATCH=YES, the valid range is 1600 to 3200. Any other value will be reset to the default value of 3200. AWM is always active and cannot be turned off.

Default Value: AWM is active. For HIPERDISPATCH=NO, the default is 12000 (12 ms). For HIPERDISPATCH=YES, the default is 3200 (3.2 ms).

There can be a very significant effect on performance by using large values (such as 490,000) to activate AWM. IBM® suggests accepting the default value. Specify a value for CCCAWMT in order to override the default after consulting with the IBM Support Center. Do not specify what is thought to be the default value as a means of disabling any OPT control. Default values sometimes change over time. Always convert a control to a comment (see the following) if the objective is to use the default value while retaining a reminder of the last value used.
```
	/* CCCAWMT=500000     now a comment - used to turn off AWM   */
```
Specify a value greater than or equal to 500,000 to deactivate AWM. AWM should be active when special assist processors, such as System z® Application Assist Processors (zAAPs) and IBM System z9® Integrated Information Processors and IBM System z10® Integrated Information Processors (zIIPs) are present and IFAHONORPRIORITY=YES or IIPHONORPRIORITY=YES is specified. See the description of and for more information. You should accomplish this by removing the CCCAWMT parameter.

CCCSIGUR=option

Specifies the minimum mean-time-to-wait threshold value for heavy CPU users. This constant is used to determine the range of mean-time-to-wait values which are assigned to each of the ten mean-time-to-wait dispatching priorities. The specified real time value is adjusted by relative processor speed to become SRM time to insure consistent SRM control across various processors.

Value Range: 0-32767 milliseconds

Default Value: 45

CNTCLIST=option

Specifies if the individual commands in a TSO/E CLIST are treated as separate commands for transaction control.

In the syntax, option is either YES or NO. CNTCLIST=NO specifies that the CLIST is treated as a single transaction. CNTCLIST=YES specifies that each command is to be treated as an individual transaction. By specifying CNTCLIST=YES, SRM control of a TSO/E command becomes the same whether the command is executed explicitly or as part of a CLIST.

Values: YES or NO

Default Value: NO

CPENABLE=(xxx,yyy)

Specifies the low (ICCTPILO) and high (ICCTPIHI) threshold values for the percentage of I/O interruptions to be processed through the test pending interrupt (TPI) instruction path in IOS. SRM uses the following thresholds to control the number of processors enabled for I/O interruptions.

Value Range	Basic Mode Default	LPAR Mode Default
a=0-100%	10	0
b=0-100%	30	0

Note: For MVS™ running in LPAR mode with dedicated CPUs, specify the basic mode default values for CPENABLE. For recommendations on setting CPENABLE parameters, please see ATS Flash1033 at the following URL:

http://www-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/FLASH10337

DVIO=option

Specifies whether directed VIO is to be active in the system or not.

DVIO=YES, the default, specifies that directed VIO is to be active in the system; that is, the NONVIO keyword of the IEASYSxx parmlib member is honored. DVIO=NO specifies that directed VIO is not to be active in the system; the NONVIO parameter of the IEASYSxx parmlib member is ignored.

Values: YES or NO

Default Value: YES

FULLPRESYSTEM= [YES | NO]

Specifies the SRM to allow full preemption for the system address spaces.

In FULLPRESYSTEM=YES mode, SRM allows full preemption handling for system address spaces. To free up a processor immediately when such an address space becomes ready, the system issues signal processor (SIGP) instructions. The SIGP instructions also run in HiperDispatch mode, so when HIPERDISPATCH=YES and FULLPRESYSTEM=YES, too much LPAR overhead can result. Therefore:

Use FULLPRESYSTEM=NO when HIPERDISPATCH=YES
Use FULLPRESYSTEM=YES when HIPERDISPATCH=NO.

FULLPRESYSTEM=NO Specifies the SRM to turn off full preemption mode for the system address spaces.

Value Range: YES or NO

Default Value:

YES when HiperDispatch is not in effect.
NO when HiperDispatch is in effect.

ERV=xxxxxx

Specifies the number of CPU service units that an address space or enclave is allowed to absorb when it is possibly causing enqueue contention.

During this “enqueue residency” time, the address space (including the address space associated with an enclave) is not considered for swap-out based on recommendation value analysis. The address space or enclave runs with a high enough priority to guarantee the needed CPU time.

ERV is in effect for an address space or enclave that meets one of the following criteria:

The address space or enclave is enqueued on a system resource needed by another address space.
An authorized program in the address space or enclave obtains control of the resource (even if another address space does not need that resource) as a result of issuing a reserve for a DASD device which is SHARED.

Note: SRM determines the execution time equivalent to the specified ERV by multiplying the ERV by the model-dependent time needed to accumulate 1 CPU service unit.

Example: ERV=2

In the example above, if an address space consumes 1 service unit in 10 milliseconds, it will be allowed to execute for 20 milliseconds before it will be eligible for swap-out while enqueued on a resource requested by other address spaces.

Value Range: 0-999999

Default Value: 500

HIPERDISPATCH=YES|NO

YES

Specifies that SRM should turn on HiperDispatch mode.

NO

Specifies that SRM should turn off HiperDispatch mode.

Note: All partitions with greater than 64 logical processors defined at IPL are forced to run with HIPERDISPATCH=YES. After IPL, LPARs with greater than 64 logical processors defined are unable to switch into HIPERDISPATCH=NO. Also, when HIPERDISPATCH=YES (when it is supported by the processor), VARY CPU management is automatically turned off no matter what is specified for VARYCPU.

Note:

On IBM z13™ and follow-on processors that support multi threading mode, when partitions specify LOADxx PROCVIEW=CORE, they are forced to run with HIPERDISPATCH=YES. After IPL, these partitions are unable to switch into HIPERDISPATCH=NO. Also, when HIPERDISPATCH=YES (when it is supported by the processor), VARY CPU management is automatically turned off no matter what is specified for VARYCPU. End of change

Default Value:

For IBM zEnterprise® 196 (and follow-on processors): YES

For IBM System z10 processors: NO

IFAHONORPRIORITY=YES|NO

YES

Specifies that standard processors run both zAAP processor eligible and non-zAAP processor eligible work in priority order when the zAAP processors indicate the need for help from standard processors. The need for help is determined by the alternate wait management (AWM) function of SRM for both standard and zAAP processors. Standard processors help each other and standard processors can also help zAAP processors if YES is in effect. Specifying YES does not mean the priorities will always be honored because the system manages dispatching priorities based on the goals provided in the WLM service definition. AWM should not be disabled when IFAHONORPRIORITY=YES is in effect. See the description for parameter for a description of AWM.

If zAAP processors are defined to the LPAR but are not online, the zAAP processor eligible work units are processed by standard processors in priority order. The system ignores the IFAHONORPRIORITY parameter in this case and handles the work as if it had no eligibility to zAAP processors. The zAAP processor eligible processor times are reported in RMF™ and SMF for planning purposes.

IBM suggests that you specify or default to IFAHONORPRIORITY=YES.

NO

Specifies that standard processors will never examine zAAP processor eligible work. Note that standard processors also run zAAP processor eligible work, if it's necessary to resolve contention for resources with non-zAAP processor eligible work.

Default Value: YES

IIPHONORPRIORITY=YES|NO

YES

Specifies that standard processors run both zIIP processor eligible and non-zIIP processor eligible work in priority order when the zIIP processors indicate the need for help from standard processors. The need for help is determined by the alternate wait management (AWM) function of SRM for both standard and zIIP processors. Standard processors help each other and standard processors can also help zIIP processors if YES is in effect, which is the default. Specifying YES does not mean the priorities will always be honored because the system manages dispatching priorities based on the goals provided in the WLM service definition. AWM should not be disabled when IIPHONORPRIORITY=YES is in effect. See the description for parameter for a description of AWM.

If zIIP processors are defined to the LPAR but are not online, the zIIP processor eligible work units are processed by standard processors in priority order. The system ignores the IIPHONORPRIORITY parameter in this case and handles the work as if it had no eligibility to zIIP processors. The zIIP processor eligible processor times are reported in RMF and SMF for planning purposes.

IBM suggests that you specify or default to IIPHONORPRIORITY=YES.

NO

Specifies that standard processors will never examine zIIP processor eligible work. Note that standard processors also run zIIP processor eligible work, if it's necessary to resolve contention for resources with non-zIIP processor eligible work.

Default Value: YES

INITIMP=option

Specifies the dispatching priority for JES, APPC, and OMVS initiators. The option is specified as one of the following values:

0 — The initiator dispatching priority is set to 254.
1,2, or 3 — Defines that the initiator dispatching priority has to be lower than the dispatching priority for CPU critical work with the same or a higher importance level.
If no service class with the CPU critical attribute and a corresponding or higher importance level is defined in the WLM policy, the dispatching priority is calculated in the same way as for parameter INITIMP=E.
E — Defines that the initiator dispatching priority will be calculated in the same way as the enqueue promotion dispatching priority. The dispatching priority is calculated dynamically to ensure access to the processor. It should not impact high importance work; however, there is no guarantee that CPU critical work will always have a higher dispatching priority.

An INTIMP value affects only the system on which it has been set.

Example: INITIMP=2

With INITIMP=2, if there are service classes with an importance of 2 and the CPU critical attribute, the dispatching priority of initiator address spaces will always be lower than the dispatching priority of the work running in those service classes. Because CPU critical work with a higher importance level will always have a higher dispatching priority, the dispatching priority of the initiator will also be lower than any CPU critical work with an importance of 1.

With INITIMP=2 and CPU critical work with an importance of 1 and 3, the initiator will always have a lower dispatching priority than the work running in the service class with the CPU critical attribute and an importance of 1 but not for the work running in the CPU critical service class with an importance of 3.

With INITIMP=2 and no service classes with the CPU critical attribute and an importance of 1 or 2, the initiator dispatching priority is set to the enqueue promotion dispatching priority which is dynamically calculated. Please note that the initiators will not run at a dispatching priority of 254 as that is only the case if you do not specify the INITIMP parameter or if you have set it to 0.

Default Value: 0

IRA405I=n

Specifies the percentage of the fixed storage that causes the system to issue message IRA405I. Specify a value for n to indicate the storage area, where n can be:

0: Real storage area below 16M
1: Real storage area between 16M and 2G
2: Total real storage

Note that when you specify the percentage value, you must specify the value without the percent symbol (%), as shown in the following example:

IRA405I(1)=60

When each value of the n is specified, the value ranges and the default values for the IRA405I parameter can be:

IRA405I(0): Value Range: 0 to 100.
Default Value: 70.
IRA405I(1): Value Range: 0 to 100.
Default Value: 50.
IRA405I(2): Value Range: 0 to 100.
Default Value: 50.

MANAGENONENCLAVEWORK=option

Specifies whether non-enclave transaction work of queue servers and enclave servers is to be managed or not, where option is YES or NO.

MANAGENONENCLAVEWORK=YES indicates that SRM is to manage the non-enclave transaction work towards the first service class period of the address space performance goal. Based on this expanded performance management, be sure to verify the performance goals for the service class of the address spaces that process the enclave work. For a detailed description, see the chapter "Performance Management of Address Spaces with Enclaves" in Start of change z/OS MVS Programming: Workload Management Services End of change .

MANAGENONENCLAVEWORK=NO indicates that you expect no work consuming significant CPU service to be running in the address space outside of an enclave. The CPU consumption of work running outside of enclaves is not included when workload management assesses the impact of CPU adjustments for the enclave work.

This performance management is available for z/OS® V1R12 and later releases.

Note: To complete a MANAGENONENCLAVEWORK status change from YES to NO or NO to YES for an active system, SRM issues a policy refresh for that active system. Workload Manager indicates the policy refresh for this status change with message IWM065I.

Values: YES or NO

Default Value: NO

Example: MANAGENONENCLAVEWORK=YES

In the example, SRM is to manage the non-enclave work of enclave servers and queue servers

MAXPROMOTETIME=xxxx

Specifies the time during which a resource holder is allowed to run promoted when it is possibly causing a resource contention. A resource holder is either an address space or enclave. During this "resource contention residency" time, the resource holder runs with the highest priority of all resource waiters to guarantee the needed importance. Also during this interval, the address space (including the address space associated with an enclave) is not considered for swap-out based on recommendation value analysis. If MAXPROMOTETIME=0 is specified, SRM does not promote any resource holder.

MAXPROMOTETIME is in effect if the resource manager has notified the address space or enclave under contention by using the WLM IWMCNTN notification service. See z/OS MVS Programming: Workload Management Services for a description of the WLM IWMCNTN service.

The value specified for MAXPROMOTETIME is multiplied by 10. This is the time span in seconds during which the address space or enclave under contention is allowed to run promoted.

Example: MAXPROMOTETIME=12

With MAXPROMOTETIME=12, SRM allows an address space or enclave to run 12 × 10 seconds (=2 minutes) promoted. When the time is exceeded, the promotion is canceled.

Value Range: 0-1000

Default Value: 6

MCCAFCTH=(lowvalue,okvalue)

Specifies the low and the OK threshold values for storage. The lowvalue indicates the number of frames on the available frame queue when stealing begins. The okvalue indicates the number of frames on the available frame queue when stealing ends. SRM will automatically adjust the actual threshold values based on measurements of storage usage, but threshold values should never fall below the values specified in MCCAFCTH. You do not have to specify an MCCAFCTH value.

If the lowvalue or okvalue is below the default value, the default value is enforced.

Value: lowvalue=1-32767 frames
Default: The maximum of 400 and 0.2% of the pageable storage in the system
Value: okvalue=1-32767 frames
Default: The maximum of 400 and 0.2% of the pageable storage in the system

MCCFXEPR=xxx

Specifies the percentage of storage that is fixed within the first 16 megabytes. SRM uses this threshold to determine when a shortage of pageable storage exists because there are too many fixed pages.

Value Range: 0-100 percent

Default Value: 92 percent

MCCFXTPR=xxx

Specifies the percentage of online storage that Start of change

might be

fixed. SRM uses this threshold to determine when a shortage of pageable storage exists.

Note: SRM uses the lesser of the values, (MCCFXTPR × amount of online storage) and (MCCFXEPR × amount of storage that is fixed within the first 16 megabytes) to set the threshold frame count so that it can detect a shortage of pageable storage that is caused by too much page fixing. In this way, SRM can detect a shortage of pageable storage that is caused by too much page fixing before or at the same time as a shortage caused by too much paging.

Value range: 0-100 percent

Default value: Start of change

On small systems (less than 320 GB), the target is End of change

80 percent Start of change

. On large systems (more than 320 GB), the target is total storage minus 64 GB. End of change

Note:

If 100% - MCCFXTPR * the total amount of online frames is greater than 64 gigabytes, the MCCFXTPR keyword is not used in determining the threshold at which a shortage of pageable storage exists.

Instead, on systems with more than 320 gigabytes of storage, a pageable storage shortage is detected when less than 64 gigabytes of online storage is pageable.

When calculating the number of frames that can be page fixed before a pageable storage shortage is detected, SRM uses the maximum of MCCFXTPR * the total online frames and total online storage minus 64 gigabytes.

MT_CP_MODE=1

MT_ZIIP_MODE=1|2

Specifies the multithreading (MT) mode, which is the number of active threads per core for all online cores with a core type of standard CP, or System z Integrated Information Processor (zIIP).

Default Value: 1

MT_CP_MODE=: The number of active threads for each online CP core. For CPs only a value of 1 is valid.
MT_ZIIP_MODE: The number of active threads for each online zIIP core. The value is limited to what the underlying hardware and operating system support.

A value of 1 is always accepted.

Activating an MT mode greater than 1, requires the following:

The hardware must support multithreading for the respective processor class, namely zIIPs.
On the HMC Customize/Delete Activation Profiles task, "Do not end the time slice if a partition enters a wait state" must not be checked. This is the recommended default setting.
The system must be IPLed with LOADxx PROCVIEW CORE in effect.
HIPERDISPATCH=YES must be in effect.

If these requirements are met, the MT mode for all cores of the respective processor class is changed to the specified Start of change value/mode End of change if the current MT mode is different from that value. In case of a successful change of the MT Mode, message IWM066 is issued. For an unsuccessful request, message IWM067 is issued.

Changing the MT Mode for all cores of the same type can take multiple seconds to complete.

PROJECTCPU=[YES | NO]

Specifies whether to activate or deactivate the projection of how work could be offloaded from regular CPs to special assist processors like the System z Application Assist Processor (zAAP) and the System z Integrated Information Processor (zIIP).

Note:

The PROJECTCPU parameter is not necessary if you can define a zIIP or zAAP as a reserved processor in the LPAR configuration. The PROJECTCPU parameter is provided for users of earlier processors on which defining a zIIP as a reserved processor is not supported when no zIIP is purchased for planning purposes.
If the installation requires ZIIP statistics but there is no ZIIP defined (reserved or actual) on the LPAR, then PROJECTCPU=YES is required regardless of hardware model.
Any work that is eligible for being offloaded to a special assist processor will be reported as Special_Processor_on_CP work. This information can be used to understand the benefit of adding a special processor into the configuration.

Values: YES or NO

Default Value: NO - projection will not be done, unless a special assist processor is configured to the system. In that case, the system will collect projection values.

RCCFXET=option

SRM uses these thresholds to determine whether the system MPL needs to be increased or decreased based on the first 16 MB. The values that you can specify for option are as follows:

(aaa,bbb): Specifies the low (RCCFXETL) and the high (RCCFXETH) percentages of storage that is fixed within the first 16 megabytes.

Value range: 0-100 percent

Default values:

aaa = 82
bbb = 88

RCCFXTT=option

SRM uses these thresholds to determine if the system MPL needs to be increased or decreased. The values that you can specify for option are as follows:

(aaa,bbb): Specifies the low (RCCFXTTL) and the high (RCCFXTTH) percentages of online storage that is fixed.

Value range: 0-100 percent

Default values:

aaa = 66
bbb = 72

RMPTTOM=xxxxxx

Specifies the SRM invocation interval. The specified real-time interval is adjusted by relative processor speed to become SRM time in order to ensure consistent SRM control across various processors. The relationship of real time to SRM time for each processor is described in the “Advanced SRM Parameter Concepts” topic of z/OS MVS Initialization and Tuning Guide.

Value Range: 1000-999999 msec

Default Value:

3000 (for systems with a uni-processor speed of more than 100 MIPS)
1000 (for systems with a uni-processor speed of 100 MIPS or less)

RTPIFACTOR=xxx

Specifies how much the server performance index (PI) should affect the server routing weights returned by WLM services IWM4SRSC and IWMSRSRS with FUNCTION=SPECIFIC.

When RTPIFACTOR is 0, the server weight is independent from the server PI.
When RTPIFACTOR is 100 and the server PI is bigger than 1, the server weight is divided by the server PI.
When RTPIFACTOR is between 1 and 99, it results in a corresponding intermediate influence of the server PI on the server weight returned by WLM.

Value Range: 0-100

Default Value: 100

STORAGENSWDP=option

Specifies if the system should select non-swappable address spaces to resolve a storage shortage.

STORAGENSWDP=YES specifies that the system should also select non-swappable address spaces to resolve the storage shortage. The system then sets non-swappable address spaces non-dispachable and issues message IRA210E or IRA410E.

Note: The system does not set address spaces in service class SYSTEM non-dispatchable.

Values: YES or NO

Default Value: YES

STORAGESERVERMGT=option

Specifies whether SRM should pass service class importance and goal information to the storage I/O priority manager in the IBM System Storage® DS8000® series. The passed information enables the storage I/O priority manager to provide favored processing for I/O requests of important z/OS workloads that are missing their goals.

STORAGESERVERMGT=YES specifies that SRM should pass service class importance and goal information to the storage I/O priority manager. Before specifying STORAGESERVERMGT=YES, verify that your IBM System Storage DS8000 model incorporates the storage I/O priority manager feature.

If STORAGESERVERMGT=YES is specified, the storage I/O priority manager may throttle I/O requests to facilitate a favored access to storage server resources for other I/O requests. The storage I/O priority manager considers the properties of the service class period associated with an I/O request to determine whether the I/O request should receive a favored processing or may be throttled:

For service class periods with a response time goal, the goal achievement and specified importance are considered.
For service class periods with a velocity goal, the specified velocity goal and importance are considered.
I/O requests associated with the system-provided service classes SYSTEM, SYSSTC, or SYSSTC1 - SYSSTC5 are not managed by the I/O priority manager.
I/O requests associated with service class periods that have a discretionary goal will always be throttled.

Throttle delays introduced by the storage IO priority manager are reflected in control unit queue delays. Therefore, if STORAGESERVERMGT=YES is specified, control unit queue delays are not considered when the achieved velocity and performance index are calculated for service class periods with a velocity goal.

If you have significant control unit queue delays in your installation, you may have to adjust the velocity goal of service class periods when you specify STORAGESERVERMGT=YES.

Values: YES or NO

Default Value: NO

STORAGEWTOR=option

Specifies how the system handles address spaces in a critical storage shortage.

STORAGEWTOR=YES specifies that the system presents a list of address spaces on the console. The operator can reply to a WTOR (IRA221D or IRA421D) request and select which address space to cancel. STORAGEWTOR=AUTO is similar to STORAGEWTOR=YES, except that the IRA210I or IRA420I message presents up to 20 address spaces at once. This option is useful, when an automation product needs to answer the WTOR request.

Values: YES, AUTO, or NO

Default Value: YES

TIMESLICES=option

Specifies the number of timeslices that a CPU-intensive address space or enclave with a discretionary goal should be given before a dispatchable unit of equal importance is dispatched.

Increasing this parameter might increase the processor delay for some CPU-intensive work, but decrease the number of context switches between equal priority work, and therefore increase the throughput of the system. This parameter only affects discretionary work that is CPU-intensive as determined by significant mean time to wait (MTTW) (see parameter CCCSIGUR).

Value Range: 1-255

Default Value: 1

VARYCPU=option

Specifies whether LPAR Vary CPU management is available or not available. Note that Vary CPU management is available only in a partition that is enabled for LPAR weight management. Also, Vary CPU management is automatically turned off no matter what is specified for VARYCPU, if HIPERDISPATCH is on.

VARYCPU=YES, the default, specifies that LPAR Vary CPU Management is available for this system. VARYCPU=NO specifies that LPAR Vary CPU Management is not available.

Value Range: YES or NO

Default Value: YES

VARYCPUMIN=nn

Specifies the minimum number of CPs (nn) that must stay online during WLM LPAR management. WLM LPAR management will not take CPs offline below this threshold.

Value Range: 1 - 64

Default Value: 1

WASROUTINGLEVEL=0|1

Specifies the routing algorithm used by the WLM Websphere routing services.

0

WLM uses the most advanced routing algorithm that is supported by all systems in the sysplex.

If the release level of the lowest system is z/OS R9 (or above), routing decisions are based on available or dispatchable capacity of standard and assist processors.
If the release level of the lowest system is below z/OS R9, but has the APAR OA16486 installed, routing decisions are based on available or dispatchable capacity of standard processors only.
If the release level of the lowest system is below z/OS R9 and runs without the APAR OA16486 installed, the routing algorithm round robin is used.

1

WLM uses the routing algorithm round robin. If this option is used, set it on all systems of the sysplex so that all are using the same algorithm; otherwise, the WebSphere® routing service on each system uses the specific algorithm setting for the system, which can lead to inconsistent results.

Default Value: 0

ZAAPAWMT=xxxxxx

Specifies an Alternate Wait Management (AWM) value for IBM System z Application Assist Processors (zAAPs) to minimize SRM and LPAR low utilization effects and overhead. In an LPAR, some n-way environments with a small workload may appear to have little capacity remaining because of the time spent waking up idle zAAPs to compete for individual pieces of work. The ZAAPAWMT parameter allows you to reduce this time so that capacity planning is more accurate and CPU overhead is reduced, even though it might take longer until arriving work gets dispatched.

Value Range: For HIPERDISPATCH=NO, the valid range is 1 to 499999 microseconds. Any value between 1 and 499999 makes AWM active. To inactivate AWM, set CCCAWMT to any value between 500000 and 1000000.

For HIPERDISPATCH=YES, the valid range is 1600 to 499999 microseconds. Any other value will be reset to the default value of 3200. AWM is always active and cannot be turned off.

Default Value: AWM is active. For HIPERDISPATCH=NO, the default is 12000 (12 ms), and for HIPERDISPATCH=YES, the default is 3200 (3.2 ms).

ZIIPAWMT=xxxxxx

Specifies an Alternate Wait Management (AWM) value for the IBM System z9 Integrated Information Processor (zIIP) to minimize SRM and LPAR low utilization effects and overhead. In an LPAR, some n-way environments with a small workload may appear to have little capacity remaining because of the time spent waking up idle zIIPs to compete for individual pieces of work. The ZIIPAWMT parameter allows you to reduce this time so that capacity planning is more accurate and CPU overhead is reduced, even though it might take longer until arriving work gets dispatched.

Value Range: For HIPERDISPATCH=NO, the valid range is between 1 and 499999 microseconds. Any value between 1 to 499999 makes AWM active. To inactivate AWM, set CCCAWMT to any value between 500000 and 1000000.

For HIPERDISPATCH=YES, the valid range is 1600 to 499999 microseconds. Any other value will be reset to the default value of 3200. AWM is always active and cannot be turned off.

Default Value: AWM is active. For HIPERDISPATCH=NO, the default is 12000 (12 ms), and for HIPERDISPATCH=YES, the default is 3200 (3.2 ms).

Note:

The ZAAPAWMT and ZIIPAWMT parameters internally affect the frequency with which the specialty engines will check the need for help. If help is required, the zAAP or zIIP processor signals a waiting zAAP or zIIP to help. When all zAAP or zIIP processors are busy and IFAHONORPRIORITY/IIPHONORPRIORITY=YES, the zAAP or zIIP processors ask for help from the standard processors. All available speciality engines (that is, all zAAPs or all zIIPs) must be busy before help is asked of the standard processors. Even with IFAHONORPRORITY=YES or IIPHONORPRIORITY=YES parameters set, the general CP will not help the specialty engine for work in a discretionary service class.

Reducing the value specified for ZAAPAWMT or ZIIPAWMT causes the specialty engines to request help after being busy for a shorter period of time. If IFAHONORPRIORITY or IIPHONORPRIORITY is set to YES, help is provided to one CP at a time, in the priority order of zAAP or zIIP processor eligible work, non-zAAP or non-zIIP processor eligible work. Reducing the ZAAPAWMT or ZIIPAWMT value too low can cause the standard processors to run an excessive amount of zAAP or zIIP processor eligible workload, which might result in lower priority non-zAAP/zIIP processor eligible work to be delayed. Conversely, increasing the value specified for ZAAPAWMT or ZIIPAWMT causes the specialty engines to request help only after being busy for a longer period of time, which might delay the standard processors from providing help when it is necessary.