scancel - Man Page

Used to signal jobs or job steps that are under the control of Slurm.

Examples (TL;DR)

Synopsis

scancel [Options...] [job_id[_array_id][.step_id]] [job_id[_array_id][.step_id]...]

Description

scancel is used to signal or cancel jobs, job arrays or job steps. An arbitrary number of jobs or job steps may be signaled using job specification filters or a space separated list of specific job and/or job step IDs. If the job ID of a job array is specified with an array ID value and the job associated with the array ID value has been split from the array, then only that job array element will be cancelled. If the job ID of a job array is specified without an array ID value or the array ID value corresponds to a job that has not been split from the array, then all job array elements will be cancelled. While a heterogeneous job is in a PENDING state, only the entire job can be cancelled rather than its individual components. A request to cancel an individual component of a heterogeneous job while in a PENDING state will return an error. After the job has begun execution, an individual component can be cancelled except for component zero. If component zero is cancelled, the whole het job is cancelled. A job or job step can only be signaled by the owner of that job or user root. If an attempt is made by an unauthorized user to signal a job or job step, an error message will be printed and the job will not be signaled.

Options

-A,  --account=account

Restrict the scancel operation to jobs under this charge account.

-b,  --batch

By default, signals other than SIGKILL are not sent to the batch step (the shell script). With this option scancel signals only the batch step, but not any other steps. This is useful when the shell script has to trap the signal and take some application defined action. Most shells cannot handle signals while a command is running (i.e. is a child process of the batch step), so the shell needs to wait until the command ends to then handle the signal. Children of the batch step are not signaled with this option. If this is desired, use -f, --full instead. NOTE: If used with -f, --full, this option ignored. NOTE: This option is not applicable if step_id is specified. NOTE: The shell itself may exit upon receipt of many signals. You may avoid this by explicitly trap signals within the shell script (e.g. "trap <arg> <signals>"). See the shell documentation for details.

-M,  --clusters=<string>

Cluster to issue commands to. Implies --ctld. Note that the slurmdbd must be up for this option to work properly, unless running in a federation with FederationParameters=fed_display configured.

--ctld

If this option is not used with --interactive, --sibling, or specific step ids, then this issues a single request to the slurmctld to signal all jobs matching the specified filters. This greatly improves the performance of slurmctld and scancel. Otherwise, this option causes scancel to send each job signal request to the slurmctld daemon rather than directly to the slurmd daemons, which increases overhead, but offers better fault tolerance. --ctld is the default behavior on architectures using front end nodes, or when the --clusters option is used.

-c,  --cron

Confirm request to cancel a job submitted by scrontab. This option only has effect with the "explicit_scancel" option is set in ScronParameters.

-f,  --full

By default, signals other than SIGKILL are not sent to the batch step (the shell script). With this option scancel also signals the batch script and its children processes. Most shells cannot handle signals while a command is running (i.e. is a child process of the batch step), so the shell needs to wait until the command ends to then handle the signal. Unlike -b, --batch, children of the batch step are also signaled with this option. NOTE: srun steps are also children of the batch step, so steps are also signaled with this option.

--help

Print a help message describing all scancel options.

-H,  --hurry

Do not stage out any burst buffer data.

-i,  --interactive

Interactive mode. Confirm each job_id.step_id before performing the cancel operation.

-n,  --jobname=job_name, --name=job_name

Restrict the scancel operation to jobs with this job name.

--me

Restrict the scancel operation to jobs owned by the current user.

-w,  --nodelist=host1,host2,...

Cancel any jobs using any of the given hosts. The list may be specified as a comma-separated list of hosts, a range of hosts (host[1-5,7,...] for example), or a filename. The host list will be assumed to be a filename only if it contains a "/" character.

-p,  --partition=partition_name

Restrict the scancel operation to jobs in this partition.

-q,  --qos=qos

Restrict the scancel operation to jobs with this quality of service.

-Q,  --quiet

Do not report an error if the specified job is already completed. This option is incompatible with the --verbose option.

-R,  --reservation=reservation_name

Restrict the scancel operation to jobs with this reservation name.

--sibling=cluster_name

Remove an active sibling job from a federated job.

-s,  --signal=signal_name

The name or number of the signal to send. If this option is not used the specified job or step will be terminated.

-t,  --state=job_state_name

Restrict the scancel operation to jobs in this state. job_state_name may have a value of either "PENDING", "RUNNING" or "SUSPENDED".

--usage

Print a brief help message listing the scancel options.

-u,  --user=user_name

Restrict the scancel operation to jobs owned by the given user.

-v,  --verbose

Print additional logging. Multiple v's increase logging detail. This option is incompatible with the --quiet option.

-V,  --version

Print the version number of the scancel command.

--wckey=wckey

Restrict the scancel operation to jobs using this workload characterization key.

Arguments

job_id

The Slurm job ID to be signaled.

step_id

The step ID of the job step to be signaled. If not specified, the operation is performed at the level of a job.

If neither --batch nor --signal are used, the entire job will be terminated.

When --batch is used, the batch shell processes will be signaled. The child processes of the shell will not be signaled by Slurm, but the shell may forward the signal.

When --batch is not used but --signal is used, then all job steps will be signaled, but the batch script itself will not be signaled.

Performance

When executing scancel without the --ctld option; or with the --ctld option and --interactive, --sibling, or specific step ids; a remote procedure call is sent to slurmctld to get all the jobs. scancel then sends a signal job remote procedure call for each job that matches the requested filters.

When executing scancel with the --ctld option and without --interactive, --sibling, or specific step ids, a single remote procedure call is sent to slurmctld to signal all jobs matching the requested filters. It is therefore recommended to use the --ctld option in order to reduce the number of remote procedure calls sent to the slurmctld.

If enough calls from scancel or other Slurm client commands that send remote procedure calls to the slurmctld daemon come in at once, it can result in a degradation of performance of the slurmctld daemon, possibly resulting in a denial of service.

Do not run scancel or other Slurm client commands that send remote procedure calls to slurmctld from loops in shell scripts or other programs. Ensure that programs limit calls to scancel to the minimum necessary for the information you are trying to gather.

Environment Variables

Some scancel options may be set via environment variables. These environment variables, along with their corresponding options, are listed below. (Note: Command line options will always override these settings.)

SCANCEL_ACCOUNT

-A, --account=account

SCANCEL_BATCH

-b, --batch

SCANCEL_CTLD

--ctld

SCANCEL_CRON

-c, --cron

SCANCEL_FULL

-f, --full

SCANCEL_HURRY

-H, --hurry

SCANCEL_INTERACTIVE

-i, --interactive

SCANCEL_NAME

-n, --name=job_name

SCANCEL_PARTITION

-p, --partition=partition_name

SCANCEL_QOS

-q, --qos=qos

SCANCEL_STATE

-t, --state=job_state_name

SCANCEL_USER

-u, --user=user_name

SCANCEL_VERBOSE

-v, --verbose

SCANCEL_WCKEY

--wckey=wckey

SLURM_CONF

The location of the Slurm configuration file.

SLURM_CLUSTERS

-M, --clusters

SLURM_DEBUG_FLAGS

Specify debug flags for scancel to use. See DebugFlags in the slurm.conf(5) man page for a full list of flags. The environment variable takes precedence over the setting in the slurm.conf.

Notes

If multiple filters are supplied (e.g. --partition and --name) only the jobs satisfying all of the filtering options will be signaled.

Cancelling a job step will not result in the job being terminated. The job must be cancelled to release a resource allocation.

To cancel a job, invoke scancel without --signal option. This will send first a SIGCONT to all steps to eventually wake them up followed by a SIGTERM, then wait the KillWait duration defined in the slurm.conf file and finally if they have not terminated send a SIGKILL. This gives time for the running job/step(s) to clean up.

If a signal value of "KILL" is sent to an entire job, this will cancel the active job steps but not cancel the job itself.

Authorization

When using SlurmDBD, users who have an AdminLevel defined (Operator or Admin) and users who are account coordinators are given the authority to invoke scancel on other users jobs.

Examples

Send SIGTERM to steps 1 and 3 of job 1234:
$ scancel --signal=TERM 1234.1 1234.3
Cancel job 1234 along with all of its steps:
$ scancel 1234
Send SIGKILL to all steps of job 1235, but do not cancel the job itself:
$ scancel --signal=KILL 1235
Send SIGUSR1 to the batch shell processes of job 1236:
$ scancel --signal=USR1 --batch 1236
Cancel all pending jobs belonging to user "bob" in partition "debug":
$ scancel --state=PENDING --user=bob --partition=debug
Cancel only array ID 4 of job array 1237
$ scancel 1237_4

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Copyright (C) 2002-2007 The Regents of the University of California. Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
Copyright (C) 2008-2011 Lawrence Livermore National Security.
Copyright (C) 2010-2022 SchedMD LLC.

This file is part of Slurm, a resource management program. For details, see <https://slurm.schedmd.com/>.

Slurm is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

Slurm is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

See Also

slurm_kill_job (3), slurm_kill_job_step (3)

Referenced By

salloc(1), sattach(1), sbatch(1), scontrol(1), slurm(1), squeue(1), srun(1).

January 2024 Slurm Commands