# Copyright 2016-2022 Swiss National Supercomputing Centre (CSCS/ETH Zurich)
# ReFrame Project Developers. See the top-level LICENSE file for details.
#
# SPDX-License-Identifier: BSD-3-Clause
#
# Scheduler implementations
#
import abc
import time
import reframe.core.fields as fields
import reframe.core.runtime as runtime
import reframe.core.shell as shell
import reframe.utility.jsonext as jsonext
import reframe.utility.typecheck as typ
from reframe.core.exceptions import JobError, JobNotStartedError
from reframe.core.launchers import JobLauncher
from reframe.core.logging import getlogger, DEBUG2
from reframe.core.meta import RegressionTestMeta
class JobScheduler(abc.ABC):
'''Abstract base class for job scheduler backends.
:meta private:
'''
@abc.abstractmethod
def make_job(self, *args, **kwargs):
'''Create a new job to be managed by this scheduler.
:meta private:
'''
@abc.abstractmethod
def emit_preamble(self, job):
'''Return the job script preamble as a list of lines.
:arg job: A job descriptor.
:returns: The job preamble as a list of lines.
:meta private:
'''
@abc.abstractmethod
def allnodes(self):
'''Return a list of all the available nodes.
:meta private:
'''
@abc.abstractmethod
def filternodes(self, job, nodes):
'''Filter nodes according to job information.
:arg job: A job descriptor.
:arg nodes: The initial set of nodes.
:returns: The filtered set of nodes.
:meta private:
'''
@abc.abstractmethod
def submit(self, job):
'''Submit a job.
:arg job: A job descriptor.
:meta private:
'''
@abc.abstractmethod
def wait(self, job):
'''Wait for a job to finish.
:arg job: A job descriptor.
:meta private:
'''
@abc.abstractmethod
def cancel(self, job):
'''Cancel a job.
:arg job: A job descriptor.
:meta private:
'''
@abc.abstractmethod
def finished(self, job):
'''Poll a job.
:arg job: A job descriptor.
:returns: :class:`True` if the job has finished, :class:`False`
otherwise.
:meta private:
'''
@abc.abstractmethod
def poll(self, *jobs):
'''Poll all the requested jobs.
:arg jobs: The job descriptors to poll.
:meta private:
'''
def log(self, message, level=DEBUG2):
'''Convenience method for logging debug messages from the scheduler
backends.
:meta private:
'''
getlogger().log(level, f'[S] {self.registered_name}: {message}')
[docs]class Job(jsonext.JSONSerializable, metaclass=JobMeta):
'''A job descriptor.
A job descriptor is created by the framework after the "setup" phase and
is associated with the test.
.. warning::
Users may not create a job descriptor directly.
'''
#: Number of tasks for this job.
#:
#: :type: integral
#: :default: ``1``
#:
#: .. note::
#: This attribute is set by the framework just before submitting the job
#: based on the test information.
#:
#: .. versionadded:: 3.11.0
num_tasks = variable(int, value=1)
#: Number of tasks per node for this job.
#:
#: :type: integral or :class:`NoneType`
#: :default: ``None``
#:
#: .. note::
#: This attribute is set by the framework just before submitting the job
#: based on the test information.
#:
#: .. versionadded:: 3.11.0
num_tasks_per_node = variable(int, type(None), value=None)
#: Number of tasks per core for this job.
#:
#: :type: integral or :class:`NoneType`
#: :default: ``None``
#:
#: .. note::
#: This attribute is set by the framework just before submitting the job
#: based on the test information.
#:
#: .. versionadded:: 3.11.0
num_tasks_per_core = variable(int, type(None), value=None)
#: Number of tasks per socket for this job.
#:
#: :type: integral or :class:`NoneType`
#: :default: ``None``
#:
#: .. note::
#: This attribute is set by the framework just before submitting the job
#: based on the test information.
#:
#: .. versionadded:: 3.11.0
num_tasks_per_socket = variable(int, type(None), value=None)
#: Number of processing elements associated with each task for this job.
#:
#: :type: integral or :class:`NoneType`
#: :default: ``None``
#:
#: .. note::
#: This attribute is set by the framework just before submitting the job
#: based on the test information.
#:
#: .. versionadded:: 3.11.0
num_cpus_per_task = variable(int, type(None), value=None)
#: Enable SMT for this job.
#:
#: :type: :class:`bool` or :class:`NoneType`
#: :default: ``None``
#:
#: .. note::
#: This attribute is set by the framework just before submitting the job
#: based on the test information.
#:
#: .. versionadded:: 3.11.0
use_smt = variable(bool, type(None), value=None)
#: Request exclusive access on the nodes for this job.
#:
#: :type: :class:`bool`
#: :default: ``false``
#:
#: .. note::
#: This attribute is set by the framework just before submitting the job
#: based on the test information.
#:
#: .. versionadded:: 3.11.0
exclusive_access = variable(bool, value=False)
#: Time limit for this job.
#:
#: See :attr:`reframe.core.pipeline.RegressionTest.time_limit` for more
#: details.
#:
#: .. note::
#: This attribute is set by the framework just before submitting the job
#: based on the test information.
#:
#: .. versionadded:: 3.11.0
time_limit = variable(type(None), field=fields.TimerField, value=None)
#: Maximum pending time for this job.
#:
#: See :attr:`reframe.core.pipeline.RegressionTest.max_pending_time` for
#: more details.
#:
#: .. note::
#: This attribute is set by the framework just before submitting the job
#: based on the test information.
#:
#: .. versionadded:: 3.11.0
max_pending_time = variable(type(None),
field=fields.TimerField, value=None)
#: Arbitrary options to be passed to the backend job scheduler.
#:
#: :type: :class:`List[str]`
#: :default: ``[]``
options = variable(typ.List[str], value=[])
#: The (parallel) program launcher that will be used to launch the
#: (parallel) executable of this job.
#:
#: Users are allowed to explicitly set the current job launcher, but this
#: is only relevant in rare situations, such as when you want to wrap the
#: current launcher command. For this specific scenario, you may have a
#: look at the :class:`reframe.core.launchers.LauncherWrapper` class.
#:
#: The following example shows how you can replace the current partition's
#: launcher for this test with the "local" launcher:
#:
#: .. code-block:: python
#:
#: from reframe.core.backends import getlauncher
#:
#: @rfm.run_after('setup')
#: def set_launcher(self):
#: self.job.launcher = getlauncher('local')()
#:
#: :type: :class:`reframe.core.launchers.JobLauncher`
launcher = variable(JobLauncher)
#: Pin the jobs on the given nodes.
#:
#: The list of nodes will be transformed to a suitable string and be
#: passed to the scheduler's options. Currently it will have an effect
#: only for the Slurm scheduler.
#:
#: :type: :class:`List[str]`
#: :default: ``[]``
#:
#: .. versionadded:: 3.11.0
pin_nodes = variable(typ.List[str], value=[])
# The sched_* arguments are exposed also to the frontend
def __init__(self,
name,
workdir='.',
script_filename=None,
stdout=None,
stderr=None,
sched_flex_alloc_nodes=None,
sched_access=[],
sched_options=None):
self._cli_options = list(sched_options) if sched_options else []
self._name = name
self._workdir = workdir
self._script_filename = script_filename or '%s.sh' % name
self._stdout = stdout or '%s.out' % name
self._stderr = stderr or '%s.err' % name
# Backend scheduler related information
self._sched_flex_alloc_nodes = sched_flex_alloc_nodes
self._sched_access = sched_access
# Live job information; to be filled during job's lifetime by the
# scheduler
self._jobid = None
self._exitcode = None
self._state = None
self._nodelist = None
self._submit_time = None
self._completion_time = None
# Job errors discovered while polling; if not None this will be raised
# in finished()
self._exception = None
@classmethod
def create(cls, scheduler, launcher, *args, **kwargs):
ret = scheduler.make_job(*args, **kwargs)
ret._scheduler = scheduler
ret.launcher = launcher
return ret
@property
def name(self):
return self._name
@property
def workdir(self):
return self._workdir
@property
def cli_options(self):
return self._cli_options
@property
def script_filename(self):
return self._script_filename
@property
def stdout(self):
return self._stdout
@property
def stderr(self):
return self._stderr
@property
def sched_flex_alloc_nodes(self):
return self._sched_flex_alloc_nodes
@property
def sched_access(self):
return self._sched_access
@property
def completion_time(self):
'''The completion time of this job as a floating point number
expressed in seconds since the epoch, in UTC.
This attribute is :class:`None` if the job hasn't been finished yet,
or if ReFrame runtime hasn't perceived it yet.
The accuracy of this timestamp depends on the backend scheduler.
The ``slurm`` scheduler backend relies on job accounting and returns
the actual termination time of the job. The rest of the backends
report as completion time the moment when the framework realizes that
the spawned job has finished. In this case, the accuracy depends on
the execution policy used. If tests are executed with the serial
execution policy, this is close to the real completion time, but
if the asynchronous execution policy is used, it can differ
significantly.
:type: :class:`float` or :class:`None`
'''
return self._completion_time
@property
def scheduler(self):
return self._scheduler
@property
def exception(self):
return self._exception
@property
def jobid(self):
'''The ID of this job.
.. versionadded:: 2.21
.. versionchanged:: 3.2
Job ID type is now a string.
:type: :class:`str` or :class:`None`
'''
return self._jobid
@property
def exitcode(self):
'''The exit code of this job.
This may or may not be set depending on the scheduler backend.
.. versionadded:: 2.21
:type: :class:`int` or :class:`None`
'''
return self._exitcode
@property
def state(self):
'''The state of this job.
The value of this field is scheduler-specific.
.. versionadded:: 2.21
:type: :class`str` or :class:`None`
'''
return self._state
@property
def nodelist(self):
'''The list of node names assigned to this job.
This attribute is :class:`None` if no nodes are assigned to the job
yet.
This attribute is set reliably only for the ``slurm`` backend, i.e.,
Slurm *with* accounting enabled.
The ``squeue`` scheduler backend, i.e., Slurm *without* accounting,
might not set this attribute for jobs that finish very quickly.
For the ``local`` scheduler backend, this returns an one-element list
containing the hostname of the current host.
This attribute might be useful in a flexible regression test for
determining the actual nodes that were assigned to the test.
For more information on flexible node allocation, see the
|--flex-alloc-nodes|_ command-line option
This attribute is *not* supported by the ``pbs`` scheduler backend.
.. versionadded:: 2.17
:type: :class:`List[str]` or :class:`None`
'''
return self._nodelist
@property
def submit_time(self):
'''The submission time of this job as a floating point number
expressed in seconds since the epoch, in UTC.
This attribute is :class:`None` if the job hasn't been submitted yet.
This attribute is set right after the job is submitted and can vary
significantly from the time the jobs starts running, depending on the
scheduler.
:type: :class:`float` or :class:`None`
'''
return self._submit_time
def prepare(self, commands, environs=None, prepare_cmds=None, **gen_opts):
environs = environs or []
if self.num_tasks <= 0:
getlogger().debug(f'[F] Flexible node allocation requested')
num_tasks_per_node = self.num_tasks_per_node or 1
min_num_tasks = (-self.num_tasks if self.num_tasks else
num_tasks_per_node)
try:
guessed_num_tasks = self.guess_num_tasks()
except NotImplementedError as e:
raise JobError('flexible node allocation is not supported by '
'this scheduler backend') from e
if guessed_num_tasks < min_num_tasks:
raise JobError(
'could not satisfy the minimum task requirement: '
'required %s, found %s' %
(min_num_tasks, guessed_num_tasks)
)
self.num_tasks = guessed_num_tasks
getlogger().debug(f'[F] Setting num_tasks to {self.num_tasks}')
with shell.generate_script(self.script_filename,
**gen_opts) as builder:
builder.write_prolog(self.scheduler.emit_preamble(self))
prepare_cmds = prepare_cmds or []
for c in prepare_cmds:
builder.write_body(c)
builder.write(runtime.emit_loadenv_commands(*environs))
for c in commands:
builder.write_body(c)
def guess_num_tasks(self):
num_tasks_per_node = self.num_tasks_per_node or 1
if isinstance(self.sched_flex_alloc_nodes, int):
if self.sched_flex_alloc_nodes <= 0:
raise JobError('invalid number of flex_alloc_nodes: %s' %
self.sched_flex_alloc_nodes)
return self.sched_flex_alloc_nodes * num_tasks_per_node
available_nodes = self.scheduler.allnodes()
getlogger().debug(
f'[F] Total available nodes: {len(available_nodes)}'
)
# Try to guess the number of tasks now
available_nodes = self.scheduler.filternodes(self, available_nodes)
if self.sched_flex_alloc_nodes.casefold() != 'all':
available_nodes = {n for n in available_nodes
if n.in_state(self.sched_flex_alloc_nodes)}
getlogger().debug(
f'[F] Selecting nodes in state '
f'{self.sched_flex_alloc_nodes!r}: '
f'available nodes now: {len(available_nodes)}'
)
return len(available_nodes) * num_tasks_per_node
def submit(self):
return self.scheduler.submit(self)
def wait(self):
if self.jobid is None:
raise JobNotStartedError('cannot wait an unstarted job')
self.scheduler.wait(self)
self._completion_time = self._completion_time or time.time()
def cancel(self):
if self.jobid is None:
raise JobNotStartedError('cannot cancel an unstarted job')
return self.scheduler.cancel(self)
def finished(self):
if self.jobid is None:
raise JobNotStartedError('cannot poll an unstarted job')
done = self.scheduler.finished(self)
if done:
self._completion_time = self._completion_time or time.time()
return done
def __eq__(self, other):
return type(self) == type(other) and self.jobid == other.jobid
def __hash__(self):
return hash(self.jobid)
class Node(abc.ABC):
'''Abstract base class for representing system nodes.
:meta private:
'''
@abc.abstractmethod
def in_state(self, state):
'''Returns whether the node is in the given state.
:arg state: The node state.
:returns: :class:`True` if the nodes's state matches the given one,
:class:`False` otherwise.
'''