sched_conf.5
NAME
sched_conf - Grid Engine default scheduler configuration file
DESCRIPTION
sched_conf defines the configuration file format for Grid Engine's
scheduler. In order to modify the configuration, use the graphical
user's interface qmon(1) or the -msconf option of the qconf(1) command.
A default configuration is provided with the Grid Engine distribution
package.
Note, Grid Engine allows backslashes (\) be used to escape newline
characters. The backslash and the newline are replaced with a space
character before any interpretation.
FORMAT
The following parameters are recognized by the Grid Engine scheduler if
present in sched_conf:
algorithm
Note: Deprecated, may be removed in future release.
Allows for the selection of alternative scheduling algorithms.
Currently default is the only allowed setting.
load_formula
A simple algebraic expression used to derive a single weighted load
value from all or part of the load parameters reported by sge_execd(8)
for each host and from all or part of the consumable resources (see
complex(5)) being maintained for each host. The load formula
expression syntax is that of a sum of weighted load values, that is:
{w1|load_val1[*w1]}[{+|-}{w2|load_val2[*w2]}[{+|-}...]]
Note, no blanks are allowed in the load formula.
The load values and consumable resources (load_val1, ...) are
specified by the name defined in the complex (see complex(5)).
Note: Administrator-defined load values (see the load_sensor parameter
in sge_conf(5) for details) and consumable resources available for all
hosts (see complex(5)) may be used as well as Grid Engine default load
parameters.
The weighting factors (w1, ...) are positive integers. After the
expression is evaluated for each host the results are assigned to the
hosts and are used to sort the hosts corresponding to the weighted
load. The sorted host list is used to sort queues subsequently.
The default load formula is np_load_avg.
job_load_adjustments
The load which is imposed by the Grid Engine jobs running on a system
varies in time, and often, e.g. for the CPU load, requires some amount
of time to be reported in the appropriate quantity by the operating
system. Consequently, if a job was started very recently, the reported
load may not provide a sufficient representation of the load which is
already imposed on that host by the job. The reported load will adapt
to the real load over time, but the period of time in which the
reported load is too low may already lead to an oversubscription of
that host. Grid Engine allows the administrator to specify
job_load_adjustments which are used in the Grid Engine scheduler to
compensate for this problem.
The job_load_adjustments are specified as a comma-separated list of
arbitrary load parameters or consumable resources and (separated by an
equal sign) an associated load correction value. Whenever a job is
dispatched to a host by the scheduler, the load parameter and
consumable value set of that host is increased by the values provided
in the job_load_adjustments list. These correction values are decayed
linearly over time until after load_adjustment_decay_time from the
start the corrections reach the value 0. If the job_load_adjustments
list is assigned the special denominator NONE, no load corrections are
performed.
The adjusted load and consumable values are used to compute the
combined and weighted load of the hosts with the load_formula (see
above) and to compare the load and consumable values against the load
threshold lists defined in the queue configurations (see
queue_conf(5)). If the load_formula consists simply of the default CPU
load average parameter np_load_avg, and if the jobs are very compute
intensive, one might want to set the job_load_adjustments list to
np_load_avg=1.00, which means that every new job dispatched to a host
will require 100% CPU time, and thus the machine's load is instantly
increased by 1.00.
load_adjustment_decay_time
The load corrections in the "job_load_adjustments" list above are
decayed linearly over time from the point of the job start, where the
corresponding load or consumable parameter is raised by the full
correction value, until after a time period of
"load_adjustment_decay_time" the correction becomes 0. Proper values
for "load_adjustment_decay_time" greatly depend upon the load or
consumable parameters used and the specific operating system(s).
Therefore, they can only be determined on-site and experimentally. For
the default np_load_avg load parameter a "load_adjustment_decay_time"
of 7 minutes has proven to yield reasonable results.
maxujobs
The maximum number of jobs any user may have running in a Grid Engine
cluster at the same time. If set to 0 (default) the users may run an
arbitrary number of jobs.
schedule_interval
At the time the scheduler thread initially registers with the event
master thread in the sge_qmaster(8) process schedule_interval is used
to set the time interval in which the event master thread sends
scheduling event updates to the scheduler thread. A scheduling event
is a status change that has occurred within sge_qmaster(8) which may
trigger or affect scheduler decisions (e.g. a job has finished and thus
the allocated resources are available again).
In the Grid Engine default scheduler the arrival of a scheduling event
report triggers a scheduler run. The scheduler waits for event reports
otherwise.
Schedule_interval is a time value (see sge_types(5) for a definition of
the syntax of time values). Setting it to 0 disables scheduling.
queue_sort_method
This parameter determines in which order several criteria are taken
into account to produce a sorted queue instance list which determines
the preferred order for scheduling tasks to them (typically determining
the order in which hosts are used). Currently, two settings are valid:
seqno and load. However in both cases, Grid Engine attempts to maximize
the number of soft requests (see qsub(1) -s option) being fulfilled by
the queues for a particular job as the primary criterion.
Then, if the queue_sort_method parameter is set to seqno, Grid Engine
will use the seq_no parameter as configured in the current queue
configurations (see queue_conf(5)) as the next criterion to sort the
queue list. The load_formula (see above) is only used as the next
criterion if two queues have equal sequence numbers. If
queue_sort_method is set to load the load according the load_formula is
the criterion after maximizing a job's soft requests, and the sequence
number is only used if two hosts have the same load. The sequence
number sorting is most useful if you want to define a fixed order in
which queues are to be filled (e.g. the cheapest resource first).
The default for this parameter is load.
halftime
When executing under a share based policy, the scheduler "ages" (i.e.
decreases) usage to implement a sliding window for achieving the share
entitlements as defined by the share tree. The halftime defines the
time interval in which accumulated usage will have been decayed to half
its value at the start of the interval. (This is a radioactive-type
exponential decay, where the parameter is usually called "half-life".)
Valid values are specified in hours, default 168.
If the value is set to 0, the usage is not decayed.
usage_weight_list
Grid Engine accounts for the consumption of the resources CPU-time,
memory and IO to determine the usage which is imposed on a system by a
job. A single usage value is computed from these three input parameters
by multiplying the individual values by weights and adding them up. The
weights are defined in the usage_weight_list. The format of the list is
cpu=wcpu,mem=wmem,io=wio
where wcpu, wmem and wio are the configurable weights. The weights are
real numbers. The sum of all three weights should be 1. The default is
cpu=1,mem=0,io=0.
compensation_factor
Determines how fast Grid Engine should compensate for past usage below
or above the share entitlement defined in the share tree. Recommended
values are between 2 and 10, where 10 means faster compensation. The
default is 5.
weight_user
The relative importance of the user shares in the functional policy.
Values are of type real.
weight_project
The relative importance of the project shares in the functional policy.
Values are of type real.
weight_department
The relative importance of the department shares in the functional
policy. Values are of type real.
weight_job
The relative importance of the job shares in the functional policy.
Values are of type real.
weight_tickets_functional
The maximum number of functional tickets available for distribution by
Grid Engine. Determines the relative importance of the functional
policy. See under sge_priority(5) for an overview on job priorities.
weight_tickets_share
The maximum number of share based tickets available for distribution by
Grid Engine. Determines the relative importance of the share tree
policy. See under sge_priority(5) for an overview on job priorities.
weight_deadline
The weight applied on the remaining time until a job's latest start
time. Determines the relative importance of the deadline. See under
sge_priority(5) for an overview on job priorities.
weight_waiting_time
The weight applied on the job's waiting time since submission.
Determines the relative importance of the waiting time. See under
sge_priority(5) for an overview on job priorities.
weight_urgency
The weight applied on jobs' normalized urgency when determining the
priority finally used. Determines the relative importance of urgency.
See under sge_priority(5) for an overview on job priorities.
weight_priority
The weight applied on jobs' normalized POSIX priority when determining
the priority finally used. Determines the relative importance of POSIX
priority. See under sge_priority(5) for an overview on job priorities.
weight_ticket
The weight applied on the normalized ticket amount when determining the
priority finally used. Determines the relative importance of the
ticket policies. See under sge_priority(5) for an overview on job
priorities.
flush_finish_sec
This parameter is provided for tuning the system's scheduling behavior.
By default, a scheduler run is triggered in the scheduler interval.
When this parameter is set to 1 or larger, the scheduler will be
triggered that number of seconds after a job has finished. Setting this
parameter to 0 disables the flush after a job has finished.
flush_submit_sec
This parameter is provided for tuning the system's scheduling behavior.
By default, a scheduler run is triggered in the scheduler interval.
When this parameter is set to 1 or larger, the scheduler will be
triggered that number of seconds after a job was submitted to the
system. Setting this parameter to 0 disables the flush after a job was
submitted.
schedd_job_info
The default scheduler can keep track of why jobs could not be scheduled
during the last scheduler run. This parameter enables or disables the
observation. The value true enables the monitoring false turns it off.
It is also possible to activate the observation only for certain jobs.
This will be done if the parameter is set to job_list followed by a
comma-separated list of job ids.
The user can obtain the collected information with the command qstat
-j.
params
This is for passing additional parameters to the Grid Engine scheduler.
The following values are recognized:
DURATION_OFFSET
If set, overrides the default of value 60 seconds. This
parameter is used by the Grid Engine scheduler when planning
resource utilization as the delta between net job runtimes and
total time until resources become available again. Net job
runtime as specified with -l h_rt=... or -l s_rt=... or
default_duration always differs from total job runtime due to
delays before and after actual job start and finish. Among the
delays before job start is the time until the end of a
schedule_interval, the time it takes to deliver a job to
sge_execd(8), and the delays caused by prolog in queue_conf(5),
start_proc_args in sge_pe(5) and starter_method in
queue_conf(5). The delays after job finish include those due to
a forced job termination (notify, terminate_method or
checkpointing), procedures run after actual job finish, such as
stop_proc_args in sge_pe(5) or epilog in queue_conf(5), and the
delay until a new schedule_interval.
If the offset is too low, resource reservations (see
max_reservation) can be delayed repeatedly due to an overly
optimistic job circulation time.
JC_FILTER
Note: Deprecated, may be removed in future release.
If set to true, the scheduler limits the number of jobs it looks
at during a scheduling run. At the beginning of the scheduling
run it assigns each job a specific category, which is based on
the job's requests, priority settings, and the job owner. All
scheduling policies will assign the same importance to each job
in one category. Therefore the number of jobs per category has a
FIFO order and can be limited to the number of free slots in the
system.
An exception is jobs which request a resource reservation. They
are included regardless of the number of jobs in a category.
This setting is turned off by default, because in very rare
cases, the scheduler can make a wrong decision. It is also
advised to turn report_pjob_tickets off. Otherwise qstat -ext
can report outdated ticket amounts. The information shown with a
qstat -j for a job that was excluded in a scheduling run is very
limited.
PROFILE
If set equal to 1, the scheduler logs profiling information
summarizing each scheduling run.
MONITOR
If set equal to 1, the scheduler records information for each
scheduling run, enabling reproduction of job resource
utilization in the file <sge_root>/<cell>/common/schedule.
PE_RANGE_ALG
This parameter sets the algorithm for the PE range computation.
The default is automatic, which means that the scheduler will
select the best one, and it should not be necessary to change it
to a different setting in normal operation. If a custom setting
is needed, the following values are available:
auto: the scheduler selects the best algorithm
least: starts the resource matching with the lowest slot amount
first
bin: starts the resource matching in the middle of the pe slot
range
highest: starts the resource matching with the highest slot
amount first.
Changing params will take immediate effect. The default for params is
none.
reprioritize_interval
Interval (HH:MM:SS) to reprioritize jobs on the execution hosts based
on the current ticket amount for the running jobs. If the interval is
set to 00:00:00 the reprioritization is turned off. The default value
is 00:00:00. The reprioritization tickets are calculated by the
scheduler and update events for running jobs are only sent after the
scheduler calculated new values. How often the scheduler should
calculate the tickets is defined by the reprioritize_interval. Because
the scheduler is only triggered in a specific interval
(scheduler_interval) this means the reprioritize_interval only has a
meaning if set greater than the scheduler_interval. For example, if
the scheduler_interval is 2 minutes and reprioritize_interval is set to
10 seconds, this means the jobs get re-prioritized every 2 minutes.
report_pjob_tickets
This parameter allows tuning the system's scheduling run time. It is
used to enable/disable the reporting of pending job tickets to the
qmaster. It does not influence the tickets calculation. The sort order
of jobs in qstat and qmon is only based on the submit time when the
reporting is turned off.
The reporting should be turned off in a system with a very large amount
of jobs by setting this parameter to "false".
halflife_decay_list
The halflife_decay_list allows configuring different decay rates for
the finished_jobs usage types, which is used in the pending job ticket
calculation to account for jobs which have just ended. This allows the
user the pending jobs algorithm to count finished jobs against a user
or project for a configurable decayed time period. This feature is
turned off by default, and the halftime is used instead.
The halflife_decay_list also allows one to configure different decay
rates for each usage type being tracked (cpu, io, and mem). The list is
specified in the following format:
usage_type=time[:usage_type=time[:usage_type=time]]
usage_type can be one of cpu, io, or mem. time can be -1, 0 or a
timespan specified in minutes. If time is -1, only the usage of
currently running jobs is used. 0 means that the usage is not decayed.
policy_hierarchy
This parameter sets up a dependency chain of ticket-based policies.
Each ticket-based policy in the dependency chain is influenced by the
previous policies and influences the following policies. A typical
scenario is to assign precedence for the override policy over the
share-based policy. The override policy determines in such a case how
share-based tickets are assigned among jobs of the same user or
project. Note that all policies contribute to the ticket amount
assigned to a particular job regardless of the policy hierarchy
definition. Yet the tickets calculated in each of the policies can be
different, depending on "POLICY_HIERARCHY".
The "POLICY_HIERARCHY" parameter can be an up to 3 letter combination
of the first letters of the 3 ticket based policies S(hare-based),
F(unctional) and O(verride). So a value "OFS" means that the override
policy takes precedence over the functional policy, which finally
influences the share-based policy. Less than 3 letters means that some
of the policies do not influence other policies and also are not
influenced by other policies. So a value of "FS" means that the
functional policy influences the share-based policy and that there is
no interference with the other policies.
The special value "NONE" switches off policy hierarchies.
share_override_tickets
If set to "true" or "1", override tickets of any override object
instance are shared equally among all running jobs associated with the
object. The pending jobs will get as many override tickets, as they
would have, when they were running. If set to "false" or "0", each job
gets the full value of the override tickets associated with the object.
The default value is "true".
share_functional_shares
If set to "true" or "1", functional shares of any functional object
instance are shared among all the jobs associated with the object. If
set to "false" or "0", each job associated with a functional object,
gets the full functional shares of that object. The default value is
"true".
max_functional_jobs_to_schedule
The maximum number of pending jobs to schedule in the functional
policy. The default value is 200.
max_pending_tasks_per_job
The maximum number of subtasks per pending array job to schedule. This
parameter exists in order to reduce scheduling overhead. The default
value is 50.
max_reservation
The maximum number of reservations scheduled within a schedule
interval.
When a runnable job can not be started due to a shortage of resources a
reservation can be scheduled instead. A reservation can cover
consumable resources with the global host, any execution host, and any
queue. For parallel jobs reservations are done also for the slots
resource as specified in sge_pe(5). The top max_reservation jobs (in
priority order) are considered, not individual resources. The job
runtime assumed is the maximum of the time specified with -l h_rt=...
or -l s_rt=... For jobs that have neither of them, the
default_duration (see below) is assumed.
Reservations prevent jobs of lower priority as specified in
sge_priority(5) from utilizing the reserved resource quota during the
time of reservation. Jobs of lower priority are allowed to utilize
those reserved resources only if their prospective job end is before
the start of the reservation ("backfilling"). Reservation is done only
for non-immediate jobs (-now no) that request reservation (-R y). If
max_reservation is set to "0" no job reservation is done.
max_reservation actually has a more general effect on scheduler look-
ahead, and it is necessary to turn it on for correct backfilling into
calendar windows (see calendar_conf(5)).
Note that reservation scheduling can be performance consuming and hence
reservation scheduling is switched off by default. Since reservation
scheduling performance consumption is known to grow with the number of
pending jobs, the use of the -R y option is recommended only for those
jobs actually queuing for bottleneck resources. Together with the
max_reservation parameter, this technique can be used to narrow down
performance impacts. A JSV can be used to add reservation requests for
particular resources, such as large parallel jobs.
default_duration
When job reservation is enabled through the max_reservation
sched_conf(5) parameter, the default_duration is assumed as runtime for
jobs that have neither -l h_rt=... nor -l s_rt=... specified. In
contrast to an h_rt/s_rt time limit, the default_duration is not
enforced. The default value is INFINITY, and reservation is not
effective for jobs which get that value, i.e. the value must be finite,
or jobs must specify a run time.
FILES
<sge_root>/<cell>/common/sched_configuration
scheduler thread configuration
SEE ALSO
sge_intro(1), qalter(1), qconf(1), qstat(1), qsub(1), complex(5),
queue_conf(5), sge_execd(8), sge_qmaster(8)
COPYRIGHT
See sge_intro(1) for a full statement of rights and permissions.
SGE 8.1.3pre 2011-05-17 SCHED_CONF(5)
Man(1) output converted with
man2html