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This section describes how to do the following:
It contains the following sub-sections:
Sites can configure various QoSs each with its own set of priorities, policy exemptions, and special resource access settings. They can then configure user, group, account, and class access to these QoSs. A given job will have a default QoS and may have access to several additional QoSs. When the job is submitted, the submitter may request a specific QoS or just allow the default QoS to be used. Once a job is submitted, a user may adjust the QoS of the job at any time using the setqos command. The setqos command will only allow the user to modify the QoS of that user's jobs and only change the QoS to a QoS that this user has access to. Moab administrators may change the QOS of any job to any value.
Jobs can be granted access to QoS privileges if the QoS is listed in the system default configuration QDEF (QoS default) or QLIST (QoS access list), or if the QoS is specified in the QDEF or QLIST of a user, group, account, or class associated with that job. Alternatively, a user may access QoS privileges if that user is listed in the QoSs MEMBERULIST attribute.
The mdiag -q command can be used to obtain information about the current QoS configuration including specified credential access.
The privileges enabled via QoS settings may be broken into the following categories:
All privileges are managed via the QOSCFG parameter.
|FSTARGET||Specifies QoS fairshare target.|
|FSWEIGHT||Sets QoS fairshare weight offset affecting a job's fairshare priority component.|
|PRIORITY||Assigns priority to all jobs requesting particular QoS.|
|QTTARGET||Sets QoS queuetime target affecting a job's target priority component and QoS delivered.|
|QTWEIGHT||Sets QoS queuetime weight offset affecting a job's service priority component.|
|XFTARGET||Sets QoS XFactor target affecting a job's target priority component and QoS delivered.|
|XFWEIGHT||Sets QoS XFactor weight offset affecting a job's service priority component.|
# assign priority for all qos geo jobs QOSCFG[geo] PRIORITY=10000
The QoS facility can be used to enable special services and to disable default services. These services are enabled/disabled by setting the QoS QFLAGS attribute.
|DEADLINE||Job may request an absolute or relative completion deadline and Moab will reserve resources to meet that deadline. (An alternative priority based deadline behavior is discussed in the PRIORITY FACTORS section.)|
|DEDICATED||Moab dedicates all resources of an allocated node to the job meaning that the job will not share a node's compute resources with any other job.|
|ENABLEUSERRSV||Allow user or personal reservations to be created and managed.|
|IGNALL||Scheduler ignores all resource usage policies for jobs associated with this QoS.|
Specifies how Moab should track the dynamic aspects of a job's priority. The two valid values are ACCRUE and RESET.
JOBPRIOACCRUALPOLICY is a global parameter, but can be configured to work only in QOSCFG:
The following old JOBPRIOACCRUALPOLICY values have been deprecated and should be adjusted to the following values:
Specifies exceptions for calculating a job's dynamic priority (QUEUETIME, XFACTOR, TARGETQUEUETIME). Valid values are a comma delimited list of any of the following: DEFER, DEPENDS, SOFTPOLICY, HARDPOLICY, IDLEPOLICY, USERHOLD, BATCHHOLD, and SYSTEMHOLD (ALL or NONE can also be specified on their own).
Normally, when a job violates a policy, is placed on hold, or has an unsatisfied dependency, it will not accrue priority. Exceptions can be configured to allow a job to accrue priority in spite of any of these violations. With DEPENDS a job will increase in priority even if there exists an unsatisfied dependency. With SOFTPOLICY, HARDPOLICY, or IDLEPOLICY a job can accrue priority despite violating a specific limit. With DEFER, USERHOLD, BATCHHOLD, or SYSTEMHOLD a job can accrue priority despite being on hold.
JOBPRIOEXCEPTIONS is a global parameter, but can be configured to work only in QOSCFG:
|NOBF||Job is not considered for backfill.|
|NORESERVATION||Job should never reserve resources regardless of priority.|
Job is prioritized as next to run (NTR) and backfill is disabled to prevent other jobs from jumping in front of ones with the NTR flag.
It is important to note that jobs marked with this flag should not be blocked. If they are, Moab will stop scheduling because if a job is marked with this flag, no other jobs will be run until the flagged NTR (Next to Run) job starts. Consider using the PRIORITY attribute of the QOSCFG[<QOSID>] parameter instead, when possible. Or, as you may encounter a scheduling delay for NTR-flagged jobs to start, consider using the RESERVATIONDEPTH and RESERVATIONQOSLIST parameters to provide better scheduling flow. See Reservation Policies (especially the section on Assigning Per-QoS Reservation Creation Rules) for more information.
|PREEMPTCONFIG||User jobs may specify options to alter how preemption impacts the job such as minpreempttime.|
|PREEMPTEE||Job may be preempted by higher priority PREEMPTOR jobs.|
|PREEMPTFSV||Job may be preempted by higher priority PREEMPTOR jobs if it exceeds its fairshare target when started.|
|PREEMPTOR||Job may preempt lower priority PREEMPTEE jobs.|
|PREEMPTSPV||Job may be preempted by higher priority PREEMPTOR jobs if it currently violates a soft usage policy limit.|
|PROVISION||If the job cannot locate available resources with the needed OS or software, the scheduler may provision a number of nodes to meet the needed OS or software requirements.|
|RESERVEALWAYS||Job should create resource reservation regardless of job priority.|
|RUNNOW||Boosts a job's system priority and makes the job a preemptor.
RUNNOW overrides resource restrictions such as MAXJOB or MAXPROC.
|TRIGGER||The job is able to directly specify triggers.|
|USERESERVED[:<RSVID>]||Job may only use resources within accessible reservations. If <RSVID> is specified, job may only use resources within the specified reservation.|
Example 6-32: For lowprio QoS job, disable backfill and make job preemptible
Example 6-33: Bind all jobs to chemistry reservation
Other QoS Attributes
In addition to the flags, there are attributes that alter service access.
Sets the system priority on jobs associated with this QoS.
Example: All jobs submitted under a QoS sample receive a system priority of 1
Once a system priority has been added to a job, either manually or through configuration, it can only be removed manually.
Defines the size that is requested when Elastic Computing occurs. Potential values are "PRIORITYJOBSIZE" or "<NODECOUNT>@<DURATION>". If PRIORITYJOBSIZE is set, then the nodecount and duration for Elastic Computing is set in realtime to whatever is the size of the highest priority idle job.
If desired, jobs associated with a particular QoS can be locked into a reservation or reservation group using the REQRID attribute. For example, to force jobs using QoS jasper to only use the resources within the failsafe standing reservation, use the following:
QOSCFG[jasper] REQRID=failsafe ...
All credentials, including QoS, allow specification of job usage limits as described in the Basic Fairness Policies overview. In such cases, jobs are constrained by the most limiting of all applicable policies. With QoSs, an override limit may also be specified and with this limit, jobs are constrained by the override, regardless of other limits specified. The following parameters can override the throttling policies from other credentials:
OMAXJOB, OMAXNODE, OMAXPE, OMAXPROC, OMAXPS, OMAXJPROC, OMAXJPS, OMAXJWC, and OMAXJNODE.
# staff QoS should have a limit of 48 jobs, ignoring the user limit USERCFG[DEFAULT] MAXJOB=10 QOSCFG[staff] OMAXJOB=48
Jobs can be granted access to services such as preemption and reservation creation, and they can be granted access to resource reservations. However, with QoS thresholds, this access can be made conditional on the current queuetime and XFactor metrics of an idle job. The following table lists the available QoS service thresholds:
|PREEMPTQTTHRESHOLD||A job with this QoS becomes a preemptor if the specified queuetime threshold is reached.|
|PREEMPTXFTHRESHOLD||A job with this QoS becomes a preemptor if the specified XFactor threshold is reached.|
|RSVQTTHRESHOLD||A job with this QoS can create a job reservation to guarantee resource access if the specified queuetime threshold is reached.|
|RSVXFTHRESHOLD||A job with this QoS can create a job reservation to guarantee resource access if the specified XFactor threshold is reached.|
|ACLQTTHRESHOLD||A job with this QoS can access reservations with a corresponding QoS ACL only if the specified queuetime threshold is reached.|
|ACLXFTHRESHOLD||A job with this QoS can access reservations with a corresponding QoS ACL only if the specified XFactor threshold is reached.|
|TRIGGERQTTHRESHOLD||If a job with this QoS fails to run before this threshold is reached, any failure triggers associated with this QoS will fire.|
The estimated run-time to all idle jobs for a certain QoS. More specifically, it is the processor second count of all the idle jobs in the QOS, divided by the total processors on the system.
QQOSCFG[HIGH TRIGGER=EType=threshold,AType=exec,TType=elastic,threshold=BACKLOGCOMPLETIONTIME>1,Action="$HOME/geometry.pl blah",timeout=5:00
In order to calculate the BacklogCompletionTime, the QoS must have ENABLEPROFILING=TRUE, either on the QoS itself or on the DEFAULT QoS.
Job preemption facilities can be controlled on a per-QoS basis using the PREEMPTEE and PREEMPTOR flags. Jobs that are preemptible can optionally be constrained to only be preempted in a particular manner by specifying the QoS PREEMPTPOLICY attribute as in the following example:
QOSCFG[special] QFLAGS=PREEMPTEE PREEMPTPOLICY=CHECKPOINT
For preemption to be effective, a job must be marked as a preemptee and must be enabled for the requested preemption type. For example, if the PREEMPTPOLICY is set to suspend, a potential target job must be both a preemptee and marked with the job flag SUSPENDABLE. (See suspension for more information.) If the target job is not suspendable, it will be either requeued or canceled. Likewise, if the PREEMPTPOLICY is set to requeue, the job will be requeued if it is marked restartable. Otherwise, it will be canceled.
The minimum time a job must run before being considered eligible for preemption can also be configured on a per-QoS basis using the PREEMPTMINTIME parameter, which is analogous to the JOBPREEMPTMINACTIVETIME. Conversely, PREEMPTMAXTIME sets a threshold for which a job is no longer eligible for preemption; see JOBPREEMPTMAXACTIVETIME for analogous details.
The PREEMPTEES attribute allows you to specify which QoSs that a job in a specific QoS is allowed to preempt. The PREEMPTEES list is a comma-delimited list of QoS IDs. When a PREEMPTEES attribute is specified, a job using that QoS can only preempt jobs using QoSs listed in the PREEMPTEES list. In turn, those QoSs must be flagged as PREEMPTEE as in the following example:
QOSCFG[a] QFLAGS=PREEMPTOR PREEMPTEES=b,c QOSCFG[b] QFLAGS=PREEMPTEE QOSCFG[c] QFLAGS=PREEMPTEE
In the example, jobs in the 'a' QoS can only preempt jobs in the b and c QoSs.
6.9.3.A Specifying Credential Based QoS Access
You can define the privileges allowed within a QoS by using the QOSCFG parameter; however, in most cases access to the QoS is enabled via credential specific *CFG parameters, specifically the USERCFG, GROUPCFG, ACCOUNTCFG, and CLASSCFG parameters, which allow defining QoS access lists and QoS defaults. Specify credential specific QoS access by using the QLIST and/or QDEF attributes of the associated credential parameter.
6.9.3.B QOS Access via Logical OR
To enable QoS access, the QLIST and/or QDEF attributes of the appropriate user, group, account, or class/queue should be specified as in the following example:
# user john's jobs can access QOS geo, chem, or staff with geo as default USERCFG[john] QDEF=geo QLIST=geo,chem,staff # group system jobs can access the development qos GROUPCFG[systems] QDEF=development # class batch jobs can access the normal qos CLASSCFG[batch] QDEF=normal
By default, jobs may request a QoS if access to that QoS is allowed by any of the job's credentials. (In the previous example, a job from user john submitted to the class batch could request QoSs geo, chem, staff, or normal).
6.9.3.C QOS Access via Logical AND
If desired, QoS access can be masked or logically AND'd if the QoS access list is specified with a terminating ampersand (&) as in the following example:
# user john's jobs can access QOS geo, chem, or staff with geo as default USERCFG[john] QDEF=geo QLIST=geo,chem,staff # group system jobs can access the development qos GROUPCFG[systems] QDEF=development # class batch jobs can access the normal qos CLASSCFG[batch] QDEF=normal # class debug jobs can only access the development or lowpri QoSs regardless of other credentials CLASSCFG[debug] QLIST=development,lowpri&
QoS access may also be specified from within the QoS object using the QoS MEMBERULIST attribute as in the following example:
By default, if a job requests a QoS that it cannot access, Moab places a hold on that job. The QOSREJECTPOLICY can be used to modify this behavior.
By default, jobs inherit a default QoS based on the user, group, class, and account associated with the job. If a job has access to multiple QoS levels, the submitter can explicitly request a particular QoS using the QoS resource manager extension as in the following example:
> msub -l nodes=1,walltime=100,qos=special3 job.cmd
This feature is removed for Moab 9.0 and later. You can achieve the same results using job templates.