# Copyright (c) 2018 The Regents of the University of Michigan
# All rights reserved.
# This software is licensed under the BSD 3-Clause License.
"""Implementation of the scheduling system for SLURM schedulers.
This module implements the Scheduler and ClusterJob classes for SLURM.
"""
import errno
import getpass
import logging
import subprocess
from .base import ClusterJob, JobStatus, Scheduler, _call_submit
logger = logging.getLogger(__name__)
def _fetch(user=None):
"""Fetch the cluster job status information from the SLURM scheduler.
Parameters
----------
user : str
Limit the status information to cluster jobs submitted by user.
(Default value = None)
Yields
------
:class:`~.SlurmJob`
SLURM cluster job.
"""
def parse_status(s):
s = s.strip()
if s == "PD":
return JobStatus.queued
elif s == "R":
return JobStatus.active
elif s in ["CG", "CD", "CA", "TO"]:
return JobStatus.inactive
elif s in ["F", "NF"]:
return JobStatus.error
return JobStatus.registered
if user is None:
user = getpass.getuser()
cmd = ["squeue", "-u", user, "-h", "--format=%2t%100j"]
try:
result = subprocess.check_output(cmd).decode("utf-8", errors="backslashreplace")
except subprocess.CalledProcessError:
raise
except OSError as error:
if error.errno != errno.ENOENT:
raise
else:
raise RuntimeError("SLURM not available.")
lines = result.split("\n")
for line in lines:
if line:
status = line[:2]
name = line[2:].rstrip()
yield SlurmJob(name, parse_status(status))
class SlurmJob(ClusterJob):
"""A SlurmJob is a ClusterJob managed by a SLURM scheduler."""
pass
[docs]
class SlurmScheduler(Scheduler):
r"""Implementation of the abstract Scheduler class for SLURM schedulers.
This class can submit cluster jobs to a SLURM scheduler and query their
current status.
Parameters
----------
user : str
Limit the status information to cluster jobs submitted by user.
\*\*kwargs
Forwarded to the parent constructor.
"""
# The standard command used to submit jobs to the SLURM scheduler.
submit_cmd = ["sbatch"]
def __init__(self, user=None):
self.user = user
[docs]
def jobs(self):
"""Yield cluster jobs by querying the scheduler."""
self._prevent_dos()
yield from _fetch(user=self.user)
[docs]
def submit(
self, script, *, after=None, hold=False, pretend=False, flags=None, **kwargs
):
r"""Submit a job script for execution to the scheduler.
Parameters
----------
script : str
The job script submitted for execution.
after : str
Execute the submitted script after a job with this id has
completed. (Default value = None)
hold : bool
Whether to hold the job upon submission. (Default value = False)
pretend : bool
If True, do not actually submit the script, but only simulate the
submission. Can be used to test whether the submission would be
successful. Please note: A successful "pretend" submission is not
guaranteed to succeed. (Default value = False)
flags : list
Additional arguments to pass through to the scheduler submission
command. (Default value = None)
\*\*kwargs
Additional keyword arguments (ignored).
Returns
-------
bool
True if the submission command succeeds (or in pretend mode).
Raises
------
:class:`~flow.errors.SubmitError`
If the submission command fails.
"""
if flags is None:
flags = []
elif isinstance(flags, str):
flags = flags.split()
submit_cmd = self.submit_cmd + flags
if after is not None:
submit_cmd.extend(["-W", "-d", f"afterok:{after}"])
if hold:
submit_cmd += ["--hold"]
return _call_submit(submit_cmd, script, pretend)
[docs]
@classmethod
def is_present(cls):
"""Return True if a SLURM scheduler is detected."""
try:
subprocess.check_output(["sbatch", "--version"], stderr=subprocess.STDOUT)
except subprocess.CalledProcessError:
return True
except OSError:
return False
else:
return True