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scheduler.py
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scheduler.py
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# -*- coding: utf-8 -*-
#
# Copyright 2012-2015 Spotify AB
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
"""
The system for scheduling tasks and executing them in order.
Deals with dependencies, priorities, resources, etc.
The :py:class:`~luigi.worker.Worker` pulls tasks from the scheduler (usually over the REST interface) and executes them.
See :doc:`/central_scheduler` for more info.
"""
import collections
try:
import cPickle as pickle
except ImportError:
import pickle
import datetime
import functools
import itertools
import logging
import os
import time
from luigi import six
from luigi import configuration
from luigi import notifications
from luigi import parameter
from luigi import task_history as history
from luigi.task_status import DISABLED, DONE, FAILED, PENDING, RUNNING, SUSPENDED, UNKNOWN
from luigi.task import Config
logger = logging.getLogger("luigi.server")
class Scheduler(object):
"""
Abstract base class.
Note that the methods all take string arguments, not Task objects...
"""""
add_task = NotImplemented
get_work = NotImplemented
ping = NotImplemented
UPSTREAM_RUNNING = 'UPSTREAM_RUNNING'
UPSTREAM_MISSING_INPUT = 'UPSTREAM_MISSING_INPUT'
UPSTREAM_FAILED = 'UPSTREAM_FAILED'
UPSTREAM_DISABLED = 'UPSTREAM_DISABLED'
UPSTREAM_SEVERITY_ORDER = (
'',
UPSTREAM_RUNNING,
UPSTREAM_MISSING_INPUT,
UPSTREAM_FAILED,
UPSTREAM_DISABLED,
)
UPSTREAM_SEVERITY_KEY = UPSTREAM_SEVERITY_ORDER.index
STATUS_TO_UPSTREAM_MAP = {
FAILED: UPSTREAM_FAILED,
RUNNING: UPSTREAM_RUNNING,
PENDING: UPSTREAM_MISSING_INPUT,
DISABLED: UPSTREAM_DISABLED,
}
class scheduler(Config):
# TODO(erikbern): the config_path is needed for backwards compatilibity. We should drop the compatibility
# at some point (in particular this would force users to replace all dashes with underscores in the config)
retry_delay = parameter.FloatParameter(default=900.0)
remove_delay = parameter.FloatParameter(default=600.0)
worker_disconnect_delay = parameter.FloatParameter(default=60.0)
state_path = parameter.Parameter(default='/var/lib/luigi-server/state.pickle')
# Jobs are disabled if we see more than disable_failures failures in disable_window seconds.
# These disables last for disable_persist seconds.
disable_window = parameter.IntParameter(default=3600,
config_path=dict(section='scheduler', name='disable-window-seconds'))
disable_failures = parameter.IntParameter(default=None,
config_path=dict(section='scheduler', name='disable-num-failures'))
disable_hard_timeout = parameter.IntParameter(default=None,
config_path=dict(section='scheduler', name='disable-hard-timeout'))
disable_persist = parameter.IntParameter(default=86400,
config_path=dict(section='scheduler', name='disable-persist-seconds'))
max_shown_tasks = parameter.IntParameter(default=100000)
prune_done_tasks = parameter.BoolParameter(default=False)
record_task_history = parameter.BoolParameter(default=False)
prune_on_get_work = parameter.BoolParameter(default=False)
def fix_time(x):
# Backwards compatibility for a fix in Dec 2014. Prior to the fix, pickled state might store datetime objects
# Let's remove this function soon
if isinstance(x, datetime.datetime):
return time.mktime(x.timetuple())
else:
return x
class Failures(object):
"""
This class tracks the number of failures in a given time window.
Failures added are marked with the current timestamp, and this class counts
the number of failures in a sliding time window ending at the present.
"""
def __init__(self, window):
"""
Initialize with the given window.
:param window: how long to track failures for, as a float (number of seconds).
"""
self.window = window
self.failures = collections.deque()
self.first_failure_time = None
def add_failure(self):
"""
Add a failure event with the current timestamp.
"""
failure_time = time.time()
if not self.first_failure_time:
self.first_failure_time = failure_time
self.failures.append(failure_time)
def num_failures(self):
"""
Return the number of failures in the window.
"""
min_time = time.time() - self.window
while self.failures and fix_time(self.failures[0]) < min_time:
self.failures.popleft()
return len(self.failures)
def clear(self):
"""
Clear the failure queue.
"""
self.failures.clear()
def _get_default(x, default):
if x is not None:
return x
else:
return default
class Task(object):
def __init__(self, task_id, status, deps, resources=None, priority=0, family='', module=None,
params=None, disable_failures=None, disable_window=None, disable_hard_timeout=None):
self.id = task_id
self.stakeholders = set() # workers ids that are somehow related to this task (i.e. don't prune while any of these workers are still active)
self.workers = set() # workers ids that can perform task - task is 'BROKEN' if none of these workers are active
if deps is None:
self.deps = set()
else:
self.deps = set(deps)
self.status = status # PENDING, RUNNING, FAILED or DONE
self.time = time.time() # Timestamp when task was first added
self.retry = None
self.remove = None
self.worker_running = None # the worker id that is currently running the task or None
self.time_running = None # Timestamp when picked up by worker
self.expl = None
self.priority = priority
self.resources = _get_default(resources, {})
self.family = family
self.module = module
self.params = _get_default(params, {})
self.disable_failures = disable_failures
self.disable_hard_timeout = disable_hard_timeout
self.failures = Failures(disable_window)
self.scheduler_disable_time = None
self.runnable = False
def __repr__(self):
return "Task(%r)" % vars(self)
def add_failure(self):
self.failures.add_failure()
def has_excessive_failures(self):
if (self.failures.first_failure_time is not None and
self.disable_hard_timeout):
if (time.time() >= self.failures.first_failure_time +
self.disable_hard_timeout):
return True
if self.failures.num_failures() >= self.disable_failures:
return True
return False
def can_disable(self):
return (self.disable_failures is not None or
self.disable_hard_timeout is not None)
class Worker(object):
"""
Structure for tracking worker activity and keeping their references.
"""
def __init__(self, worker_id, last_active=None):
self.id = worker_id
self.reference = None # reference to the worker in the real world. (Currently a dict containing just the host)
self.last_active = last_active or time.time() # seconds since epoch
self.started = time.time() # seconds since epoch
self.tasks = set() # task objects
self.info = {}
def add_info(self, info):
self.info.update(info)
def update(self, worker_reference):
if worker_reference:
self.reference = worker_reference
self.last_active = time.time()
def prune(self, config):
# Delete workers that haven't said anything for a while (probably killed)
if self.last_active + config.worker_disconnect_delay < time.time():
return True
def get_pending_tasks(self, state):
"""
Get PENDING (and RUNNING) tasks for this worker.
You have to pass in the state for optimization reasons.
"""
if len(self.tasks) < state.num_pending_tasks():
return six.moves.filter(lambda task: task.status in [PENDING, RUNNING],
self.tasks)
else:
return state.get_pending_tasks()
def is_trivial_worker(self, state):
"""
If it's not an assistant having only tasks that are without
requirements.
We have to pass the state parameter for optimization reasons.
"""
if self.assistant:
return False
return all(not task.resources for task in self.get_pending_tasks(state))
@property
def assistant(self):
return self.info.get('assistant', False)
def __str__(self):
return self.id
class SimpleTaskState(object):
"""
Keep track of the current state and handle persistance.
The point of this class is to enable other ways to keep state, eg. by using a database
These will be implemented by creating an abstract base class that this and other classes
inherit from.
"""
def __init__(self, state_path):
self._state_path = state_path
self._tasks = {} # map from id to a Task object
self._status_tasks = collections.defaultdict(dict)
self._active_workers = {} # map from id to a Worker object
def get_state(self):
return self._tasks, self._active_workers
def set_state(self, state):
self._tasks, self._active_workers = state
def dump(self):
try:
with open(self._state_path, 'wb') as fobj:
pickle.dump(self.get_state(), fobj)
except IOError:
logger.warning("Failed saving scheduler state", exc_info=1)
else:
logger.info("Saved state in %s", self._state_path)
# prone to lead to crashes when old state is unpickled with updated code. TODO some kind of version control?
def load(self):
if os.path.exists(self._state_path):
logger.info("Attempting to load state from %s", self._state_path)
try:
with open(self._state_path, 'rb') as fobj:
state = pickle.load(fobj)
except BaseException:
logger.exception("Error when loading state. Starting from clean slate.")
return
self.set_state(state)
self._status_tasks = collections.defaultdict(dict)
for task in six.itervalues(self._tasks):
self._status_tasks[task.status][task.id] = task
# Convert from old format
# TODO: this is really ugly, we need something more future-proof
# Every time we add an attribute to the Worker or Task class, this
# code needs to be updated
# Compatibility since 2014-06-02
for k, v in six.iteritems(self._active_workers):
if isinstance(v, float):
self._active_workers[k] = Worker(worker_id=k, last_active=v)
# Compatibility since 2015-05-28
if any(not hasattr(w, 'tasks') for k, w in six.iteritems(self._active_workers)):
# If you load from an old format where Workers don't contain tasks.
for k, worker in six.iteritems(self._active_workers):
worker.tasks = set()
for task in six.itervalues(self._tasks):
for worker_id in task.workers:
self._active_workers[worker_id].tasks.add(task)
# Compatibility since 2015-04-28
if any(not hasattr(t, 'disable_hard_timeout') for t in six.itervalues(self._tasks)):
for t in six.itervalues(self._tasks):
t.disable_hard_timeout = None
else:
logger.info("No prior state file exists at %s. Starting with clean slate", self._state_path)
def get_active_tasks(self, status=None):
if status:
for task in six.itervalues(self._status_tasks[status]):
yield task
else:
for task in six.itervalues(self._tasks):
yield task
def get_running_tasks(self):
return six.itervalues(self._status_tasks[RUNNING])
def get_pending_tasks(self):
return itertools.chain.from_iterable(six.itervalues(self._status_tasks[status])
for status in [PENDING, RUNNING])
def num_pending_tasks(self):
"""
Return how many tasks are PENDING + RUNNING. O(1).
"""
return len(self._status_tasks[PENDING]) + len(self._status_tasks[RUNNING])
def get_task(self, task_id, default=None, setdefault=None):
if setdefault:
task = self._tasks.setdefault(task_id, setdefault)
self._status_tasks[task.status][task.id] = task
return task
else:
return self._tasks.get(task_id, default)
def has_task(self, task_id):
return task_id in self._tasks
def re_enable(self, task, config=None):
task.scheduler_disable_time = None
task.failures.clear()
if config:
self.set_status(task, FAILED, config)
task.failures.clear()
def set_status(self, task, new_status, config=None):
if new_status == FAILED:
assert config is not None
# not sure why we have SUSPENDED, as it can never be set
if new_status == SUSPENDED:
new_status = PENDING
if new_status == DISABLED and task.status == RUNNING:
return
if task.status == DISABLED:
if new_status == DONE:
self.re_enable(task)
# don't allow workers to override a scheduler disable
elif task.scheduler_disable_time is not None:
return
if new_status == FAILED and task.can_disable():
task.add_failure()
if task.has_excessive_failures():
task.scheduler_disable_time = time.time()
new_status = DISABLED
notifications.send_error_email(
'Luigi Scheduler: DISABLED {task} due to excessive failures'.format(task=task.id),
'{task} failed {failures} times in the last {window} seconds, so it is being '
'disabled for {persist} seconds'.format(
failures=config.disable_failures,
task=task.id,
window=config.disable_window,
persist=config.disable_persist,
))
elif new_status == DISABLED:
task.scheduler_disable_time = None
self._status_tasks[task.status].pop(task.id)
self._status_tasks[new_status][task.id] = task
task.status = new_status
def fail_dead_worker_task(self, task, config, assistants):
# If a running worker disconnects, tag all its jobs as FAILED and subject it to the same retry logic
if task.status == RUNNING and task.worker_running and task.worker_running not in task.stakeholders | assistants:
logger.info("Task %r is marked as running by disconnected worker %r -> marking as "
"FAILED with retry delay of %rs", task.id, task.worker_running,
config.retry_delay)
task.worker_running = None
self.set_status(task, FAILED, config)
task.retry = time.time() + config.retry_delay
def prune(self, task, config):
remove = False
# Mark tasks with no remaining active stakeholders for deletion
if not task.stakeholders:
if task.remove is None:
logger.info("Task %r has stakeholders %r but none remain connected -> will remove "
"task in %s seconds", task.id, task.stakeholders, config.remove_delay)
task.remove = time.time() + config.remove_delay
# Re-enable task after the disable time expires
if task.status == DISABLED and task.scheduler_disable_time:
if time.time() - fix_time(task.scheduler_disable_time) > config.disable_persist:
self.re_enable(task, config)
# Remove tasks that have no stakeholders
if task.remove and time.time() > task.remove:
logger.info("Removing task %r (no connected stakeholders)", task.id)
remove = True
# Reset FAILED tasks to PENDING if max timeout is reached, and retry delay is >= 0
if task.status == FAILED and config.retry_delay >= 0 and task.retry < time.time():
self.set_status(task, PENDING, config)
return remove
def inactivate_tasks(self, delete_tasks):
# The terminology is a bit confusing: we used to "delete" tasks when they became inactive,
# but with a pluggable state storage, you might very well want to keep some history of
# older tasks as well. That's why we call it "inactivate" (as in the verb)
for task in delete_tasks:
task_obj = self._tasks.pop(task)
self._status_tasks[task_obj.status].pop(task)
def get_active_workers(self, last_active_lt=None):
for worker in six.itervalues(self._active_workers):
if last_active_lt is not None and worker.last_active >= last_active_lt:
continue
yield worker
def get_assistants(self, last_active_lt=None):
return filter(lambda w: w.assistant, self.get_active_workers(last_active_lt))
def get_worker_ids(self):
return self._active_workers.keys() # only used for unit tests
def get_worker(self, worker_id):
return self._active_workers.setdefault(worker_id, Worker(worker_id))
def inactivate_workers(self, delete_workers):
# Mark workers as inactive
for worker in delete_workers:
self._active_workers.pop(worker)
# remove workers from tasks
for task in self.get_active_tasks():
task.stakeholders.difference_update(delete_workers)
task.workers.difference_update(delete_workers)
def get_necessary_tasks(self):
necessary_tasks = set()
for task in self.get_active_tasks():
if task.status not in (DONE, DISABLED) or \
getattr(task, 'scheduler_disable_time', None) is not None:
necessary_tasks.update(task.deps)
necessary_tasks.add(task.id)
return necessary_tasks
class CentralPlannerScheduler(Scheduler):
"""
Async scheduler that can handle multiple workers, etc.
Can be run locally or on a server (using RemoteScheduler + server.Server).
"""
def __init__(self, config=None, resources=None, task_history_impl=None, **kwargs):
"""
Keyword Arguments:
:param config: an object of class "scheduler" or None (in which the global instance will be used)
:param resources: a dict of str->int constraints
:param task_history_override: ignore config and use this object as the task history
"""
self._config = config or scheduler(**kwargs)
self._state = SimpleTaskState(self._config.state_path)
if task_history_impl:
self._task_history = task_history_impl
elif self._config.record_task_history:
from luigi import db_task_history # Needs sqlalchemy, thus imported here
self._task_history = db_task_history.DbTaskHistory()
else:
self._task_history = history.NopHistory()
self._resources = resources or configuration.get_config().getintdict('resources') # TODO: Can we make this a Parameter?
self._make_task = functools.partial(
Task, disable_failures=self._config.disable_failures,
disable_hard_timeout=self._config.disable_hard_timeout,
disable_window=self._config.disable_window)
def load(self):
self._state.load()
def dump(self):
self._state.dump()
def prune(self):
logger.info("Starting pruning of task graph")
remove_workers = []
for worker in self._state.get_active_workers():
if worker.prune(self._config):
logger.info("Worker %s timed out (no contact for >=%ss)", worker, self._config.worker_disconnect_delay)
remove_workers.append(worker.id)
self._state.inactivate_workers(remove_workers)
assistant_ids = set(w.id for w in self._state.get_assistants())
remove_tasks = []
if assistant_ids:
necessary_tasks = self._state.get_necessary_tasks()
else:
necessary_tasks = ()
for task in self._state.get_active_tasks():
self._state.fail_dead_worker_task(task, self._config, assistant_ids)
if task.id not in necessary_tasks and self._state.prune(task, self._config):
remove_tasks.append(task.id)
self._state.inactivate_tasks(remove_tasks)
logger.info("Done pruning task graph")
def update(self, worker_id, worker_reference=None):
"""
Keep track of whenever the worker was last active.
"""
worker = self._state.get_worker(worker_id)
worker.update(worker_reference)
def _update_priority(self, task, prio, worker):
"""
Update priority of the given task.
Priority can only be increased.
If the task doesn't exist, a placeholder task is created to preserve priority when the task is later scheduled.
"""
task.priority = prio = max(prio, task.priority)
for dep in task.deps or []:
t = self._state.get_task(dep)
if t is not None and prio > t.priority:
self._update_priority(t, prio, worker)
def add_task(self, task_id=None, status=PENDING, runnable=True,
deps=None, new_deps=None, expl=None, resources=None,
priority=0, family='', module=None, params=None,
assistant=False, **kwargs):
"""
* add task identified by task_id if it doesn't exist
* if deps is not None, update dependency list
* update status of task
* add additional workers/stakeholders
* update priority when needed
"""
worker_id = kwargs['worker']
self.update(worker_id)
task = self._state.get_task(task_id, setdefault=self._make_task(
task_id=task_id, status=PENDING, deps=deps, resources=resources,
priority=priority, family=family, module=module, params=params))
# for setting priority, we'll sometimes create tasks with unset family and params
if not task.family:
task.family = family
if not getattr(task, 'module', None):
task.module = module
if not task.params:
task.params = _get_default(params, {})
if task.remove is not None:
task.remove = None # unmark task for removal so it isn't removed after being added
if expl is not None:
task.expl = expl
if not (task.status == RUNNING and status == PENDING):
# don't allow re-scheduling of task while it is running, it must either fail or succeed first
if status == PENDING or status != task.status:
# Update the DB only if there was a acctual change, to prevent noise.
# We also check for status == PENDING b/c that's the default value
# (so checking for status != task.status woule lie)
self._update_task_history(task_id, status)
self._state.set_status(task, PENDING if status == SUSPENDED else status, self._config)
if status == FAILED:
task.retry = self._retry_time(task, self._config)
if deps is not None:
task.deps = set(deps)
if new_deps is not None:
task.deps.update(new_deps)
if resources is not None:
task.resources = resources
if not assistant:
task.stakeholders.add(worker_id)
# Task dependencies might not exist yet. Let's create dummy tasks for them for now.
# Otherwise the task dependencies might end up being pruned if scheduling takes a long time
for dep in task.deps or []:
t = self._state.get_task(dep, setdefault=self._make_task(task_id=dep, status=UNKNOWN, deps=None, priority=priority))
t.stakeholders.add(worker_id)
self._update_priority(task, priority, worker_id)
if runnable:
task.workers.add(worker_id)
self._state.get_worker(worker_id).tasks.add(task)
task.runnable = runnable
def add_worker(self, worker, info, **kwargs):
self._state.get_worker(worker).add_info(info)
def update_resources(self, **resources):
if self._resources is None:
self._resources = {}
self._resources.update(resources)
def _has_resources(self, needed_resources, used_resources):
if needed_resources is None:
return True
available_resources = self._resources or {}
for resource, amount in six.iteritems(needed_resources):
if amount + used_resources[resource] > available_resources.get(resource, 1):
return False
return True
def _used_resources(self):
used_resources = collections.defaultdict(int)
if self._resources is not None:
for task in self._state.get_active_tasks():
if task.status == RUNNING and task.resources:
for resource, amount in six.iteritems(task.resources):
used_resources[resource] += amount
return used_resources
def _rank(self, task):
"""
Return worker's rank function for task scheduling.
:return:
"""
return task.priority, -task.time
def _schedulable(self, task):
if task.status != PENDING:
return False
for dep in task.deps:
dep_task = self._state.get_task(dep, default=None)
if dep_task is None or dep_task.status != DONE:
return False
return True
def _retry_time(self, task, config):
return time.time() + config.retry_delay
def get_work(self, host=None, assistant=False, **kwargs):
# TODO: remove any expired nodes
# Algo: iterate over all nodes, find the highest priority node no dependencies and available
# resources.
# Resource checking looks both at currently available resources and at which resources would
# be available if all running tasks died and we rescheduled all workers greedily. We do both
# checks in order to prevent a worker with many low-priority tasks from starving other
# workers with higher priority tasks that share the same resources.
# TODO: remove tasks that can't be done, figure out if the worker has absolutely
# nothing it can wait for
if self._config.prune_on_get_work:
self.prune()
worker_id = kwargs['worker']
# Return remaining tasks that have no FAILED descendants
self.update(worker_id, {'host': host})
if assistant:
self.add_worker(worker_id, [('assistant', assistant)])
best_task = None
locally_pending_tasks = 0
running_tasks = []
upstream_table = {}
greedy_resources = collections.defaultdict(int)
n_unique_pending = 0
worker = self._state.get_worker(worker_id)
if worker.is_trivial_worker(self._state):
relevant_tasks = worker.get_pending_tasks(self._state)
used_resources = collections.defaultdict(int)
greedy_workers = dict() # If there's no resources, then they can grab any task
else:
relevant_tasks = self._state.get_pending_tasks()
used_resources = self._used_resources()
greedy_workers = dict((worker.id, worker.info.get('workers', 1))
for worker in self._state.get_active_workers())
tasks = list(relevant_tasks)
tasks.sort(key=self._rank, reverse=True)
for task in tasks:
upstream_status = self._upstream_status(task.id, upstream_table)
in_workers = (assistant and getattr(task, 'runnable', bool(task.workers))) or worker_id in task.workers
if task.status == RUNNING and in_workers:
# Return a list of currently running tasks to the client,
# makes it easier to troubleshoot
other_worker = self._state.get_worker(task.worker_running)
more_info = {'task_id': task.id, 'worker': str(other_worker)}
if other_worker is not None:
more_info.update(other_worker.info)
running_tasks.append(more_info)
if task.status == PENDING and in_workers and upstream_status != UPSTREAM_DISABLED:
locally_pending_tasks += 1
if len(task.workers) == 1 and not assistant:
n_unique_pending += 1
if best_task:
continue
if task.status == RUNNING and (task.worker_running in greedy_workers):
greedy_workers[task.worker_running] -= 1
for resource, amount in six.iteritems((task.resources or {})):
greedy_resources[resource] += amount
if self._schedulable(task) and self._has_resources(task.resources, greedy_resources):
if in_workers and self._has_resources(task.resources, used_resources):
best_task = task
else:
workers = itertools.chain(task.workers, [worker_id]) if assistant else task.workers
for task_worker in workers:
if greedy_workers.get(task_worker, 0) > 0:
# use up a worker
greedy_workers[task_worker] -= 1
# keep track of the resources used in greedy scheduling
for resource, amount in six.iteritems((task.resources or {})):
greedy_resources[resource] += amount
break
reply = {'n_pending_tasks': locally_pending_tasks,
'running_tasks': running_tasks,
'task_id': None,
'n_unique_pending': n_unique_pending}
if best_task:
self._state.set_status(best_task, RUNNING, self._config)
best_task.worker_running = worker_id
best_task.time_running = time.time()
self._update_task_history(best_task.id, RUNNING, host=host)
reply['task_id'] = best_task.id
reply['task_family'] = best_task.family
reply['task_module'] = getattr(best_task, 'module', None)
reply['task_params'] = best_task.params
return reply
def ping(self, **kwargs):
worker_id = kwargs['worker']
self.update(worker_id)
def _upstream_status(self, task_id, upstream_status_table):
if task_id in upstream_status_table:
return upstream_status_table[task_id]
elif self._state.has_task(task_id):
task_stack = [task_id]
while task_stack:
dep_id = task_stack.pop()
if self._state.has_task(dep_id):
dep = self._state.get_task(dep_id)
if dep.status == DONE:
continue
if dep_id not in upstream_status_table:
if dep.status == PENDING and dep.deps:
task_stack = task_stack + [dep_id] + list(dep.deps)
upstream_status_table[dep_id] = '' # will be updated postorder
else:
dep_status = STATUS_TO_UPSTREAM_MAP.get(dep.status, '')
upstream_status_table[dep_id] = dep_status
elif upstream_status_table[dep_id] == '' and dep.deps:
# This is the postorder update step when we set the
# status based on the previously calculated child elements
upstream_status = [upstream_status_table.get(a_task_id, '') for a_task_id in dep.deps]
upstream_status.append('') # to handle empty list
status = max(upstream_status, key=UPSTREAM_SEVERITY_KEY)
upstream_status_table[dep_id] = status
return upstream_status_table[dep_id]
def _serialize_task(self, task_id, include_deps=True):
task = self._state.get_task(task_id)
ret = {
'status': task.status,
'workers': list(task.workers),
'worker_running': task.worker_running,
'time_running': getattr(task, "time_running", None),
'start_time': task.time,
'params': task.params,
'name': task.family,
'priority': task.priority,
'resources': task.resources,
}
if task.status == DISABLED:
ret['re_enable_able'] = task.scheduler_disable_time is not None
if include_deps:
ret['deps'] = list(task.deps)
return ret
def graph(self, **kwargs):
self.prune()
serialized = {}
for task in self._state.get_active_tasks():
serialized[task.id] = self._serialize_task(task.id)
return serialized
def _recurse_deps(self, task_id, serialized):
if task_id not in serialized:
task = self._state.get_task(task_id)
if task is None or not task.family:
logger.warn('Missing task for id [%s]', task_id)
# try to infer family and params from task_id
try:
family, _, param_str = task_id.rstrip(')').partition('(')
params = dict(param.split('=') for param in param_str.split(', '))
except BaseException:
family, params = '', {}
serialized[task_id] = {
'deps': [],
'status': UNKNOWN,
'workers': [],
'start_time': UNKNOWN,
'params': params,
'name': family,
'priority': 0,
}
else:
serialized[task_id] = self._serialize_task(task_id)
for dep in task.deps:
self._recurse_deps(dep, serialized)
def dep_graph(self, task_id, **kwargs):
self.prune()
serialized = {}
if self._state.has_task(task_id):
self._recurse_deps(task_id, serialized)
return serialized
def task_list(self, status, upstream_status, limit=True, search=None, **kwargs):
"""
Query for a subset of tasks by status.
"""
self.prune()
result = {}
upstream_status_table = {} # used to memoize upstream status
if search is None:
filter_func = lambda _: True
else:
terms = search.split()
filter_func = lambda t: all(term in t.id for term in terms)
for task in filter(filter_func, self._state.get_active_tasks(status)):
if (task.status != PENDING or not upstream_status or
upstream_status == self._upstream_status(task.id, upstream_status_table)):
serialized = self._serialize_task(task.id, False)
result[task.id] = serialized
if limit and len(result) > self._config.max_shown_tasks:
return {'num_tasks': len(result)}
return result
def worker_list(self, include_running=True, **kwargs):
self.prune()
workers = [
dict(
name=worker.id,
last_active=worker.last_active,
started=getattr(worker, 'started', None),
**worker.info
) for worker in self._state.get_active_workers()]
workers.sort(key=lambda worker: worker['started'], reverse=True)
if include_running:
running = collections.defaultdict(dict)
num_pending = collections.defaultdict(int)
num_uniques = collections.defaultdict(int)
for task in self._state.get_pending_tasks():
if task.status == RUNNING and task.worker_running:
running[task.worker_running][task.id] = self._serialize_task(task.id, False)
elif task.status == PENDING:
for worker in task.workers:
num_pending[worker] += 1
if len(task.workers) == 1:
num_uniques[list(task.workers)[0]] += 1
for worker in workers:
tasks = running[worker['name']]
worker['num_running'] = len(tasks)
worker['num_pending'] = num_pending[worker['name']]
worker['num_uniques'] = num_uniques[worker['name']]
worker['running'] = tasks
return workers
def inverse_dep_graph(self, task_id, **kwargs):
self.prune()
serialized = {}
if self._state.has_task(task_id):
self._traverse_inverse_deps(task_id, serialized)
return serialized
def _traverse_inverse_deps(self, task_id, serialized):
stack = [task_id]
serialized[task_id] = self._serialize_task(task_id)
while len(stack) > 0:
curr_id = stack.pop()
for task in self._state.get_active_tasks():
if curr_id in task.deps:
serialized[curr_id]["deps"].append(task.id)
if task.id not in serialized:
serialized[task.id] = self._serialize_task(task.id)
serialized[task.id]["deps"] = []
stack.append(task.id)
def task_search(self, task_str, **kwargs):
"""
Query for a subset of tasks by task_id.
:param task_str:
:return:
"""
self.prune()
result = collections.defaultdict(dict)
for task in self._state.get_active_tasks():
if task.id.find(task_str) != -1:
serialized = self._serialize_task(task.id, False)
result[task.status][task.id] = serialized
return result
def re_enable_task(self, task_id):
serialized = {}
task = self._state.get_task(task_id)
if task and task.status == DISABLED and task.scheduler_disable_time:
self._state.re_enable(task, self._config)
serialized = self._serialize_task(task_id)
return serialized
def fetch_error(self, task_id, **kwargs):
if self._state.has_task(task_id):
return {"taskId": task_id, "error": self._state.get_task(task_id).expl}
else:
return {"taskId": task_id, "error": ""}
def _update_task_history(self, task_id, status, host=None):
try: