# -*- coding: utf-8 -*- from __future__ import (absolute_import, division, print_function, unicode_literals) import errno import logging import os import random import signal import socket import sys import time import traceback import warnings from datetime import datetime, timedelta, timezone from distutils.version import StrictVersion from uuid import uuid4 try: from signal import SIGKILL except ImportError: from signal import SIGTERM as SIGKILL from redis import WatchError from . import worker_registration from .command import parse_payload, PUBSUB_CHANNEL_TEMPLATE, handle_command from .compat import as_text, string_types, text_type from .connections import get_current_connection, push_connection, pop_connection from .defaults import (DEFAULT_RESULT_TTL, DEFAULT_WORKER_TTL, DEFAULT_JOB_MONITORING_INTERVAL, DEFAULT_LOGGING_FORMAT, DEFAULT_LOGGING_DATE_FORMAT) from .exceptions import DequeueTimeout, ShutDownImminentException from .job import Job, JobStatus from .logutils import setup_loghandlers from .queue import Queue from .registry import FailedJobRegistry, StartedJobRegistry, clean_registries from .scheduler import RQScheduler from .suspension import is_suspended from .timeouts import JobTimeoutException, HorseMonitorTimeoutException, UnixSignalDeathPenalty from .utils import (backend_class, ensure_list, enum, get_version, make_colorizer, utcformat, utcnow, utcparse) from .version import VERSION from .worker_registration import clean_worker_registry, get_keys from .serializers import resolve_serializer try: from setproctitle import setproctitle as setprocname except ImportError: def setprocname(*args, **kwargs): # noqa pass green = make_colorizer('darkgreen') yellow = make_colorizer('darkyellow') blue = make_colorizer('darkblue') logger = logging.getLogger(__name__) class StopRequested(Exception): pass def compact(l): return [x for x in l if x is not None] _signames = dict((getattr(signal, signame), signame) for signame in dir(signal) if signame.startswith('SIG') and '_' not in signame) def signal_name(signum): try: if sys.version_info[:2] >= (3, 5): return signal.Signals(signum).name else: return _signames[signum] except KeyError: return 'SIG_UNKNOWN' except ValueError: return 'SIG_UNKNOWN' WorkerStatus = enum( 'WorkerStatus', STARTED='started', SUSPENDED='suspended', BUSY='busy', IDLE='idle' ) class Worker(object): redis_worker_namespace_prefix = 'rq:worker:' redis_workers_keys = worker_registration.REDIS_WORKER_KEYS death_penalty_class = UnixSignalDeathPenalty queue_class = Queue job_class = Job # `log_result_lifespan` controls whether "Result is kept for XXX seconds" # messages are logged after every job, by default they are. log_result_lifespan = True # `log_job_description` is used to toggle logging an entire jobs description. log_job_description = True @classmethod def all(cls, connection=None, job_class=None, queue_class=None, queue=None, serializer=None): """Returns an iterable of all Workers. """ if queue: connection = queue.connection elif connection is None: connection = get_current_connection() worker_keys = get_keys(queue=queue, connection=connection) workers = [cls.find_by_key(as_text(key), connection=connection, job_class=job_class, queue_class=queue_class, serializer=serializer) for key in worker_keys] return compact(workers) @classmethod def all_keys(cls, connection=None, queue=None): return [as_text(key) for key in get_keys(queue=queue, connection=connection)] @classmethod def count(cls, connection=None, queue=None): """Returns the number of workers by queue or connection""" return len(get_keys(queue=queue, connection=connection)) @classmethod def find_by_key(cls, worker_key, connection=None, job_class=None, queue_class=None, serializer=None): """Returns a Worker instance, based on the naming conventions for naming the internal Redis keys. Can be used to reverse-lookup Workers by their Redis keys. """ prefix = cls.redis_worker_namespace_prefix if not worker_key.startswith(prefix): raise ValueError('Not a valid RQ worker key: %s' % worker_key) if connection is None: connection = get_current_connection() if not connection.exists(worker_key): connection.srem(cls.redis_workers_keys, worker_key) return None name = worker_key[len(prefix):] worker = cls([], name, connection=connection, job_class=job_class, queue_class=queue_class, prepare_for_work=False, serializer=serializer) worker.refresh() return worker def __init__(self, queues, name=None, default_result_ttl=DEFAULT_RESULT_TTL, connection=None, exc_handler=None, exception_handlers=None, default_worker_ttl=DEFAULT_WORKER_TTL, job_class=None, queue_class=None, log_job_description=True, job_monitoring_interval=DEFAULT_JOB_MONITORING_INTERVAL, disable_default_exception_handler=False, prepare_for_work=True, serializer=None): # noqa if connection is None: connection = get_current_connection() self.connection = connection self.redis_server_version = None if prepare_for_work: self.hostname = socket.gethostname() self.pid = os.getpid() else: self.hostname = None self.pid = None self.job_class = backend_class(self, 'job_class', override=job_class) self.queue_class = backend_class(self, 'queue_class', override=queue_class) self.version = VERSION self.python_version = sys.version self.serializer = resolve_serializer(serializer) queues = [self.queue_class(name=q, connection=connection, job_class=self.job_class, serializer=self.serializer) if isinstance(q, string_types) else q for q in ensure_list(queues)] self.name = name or uuid4().hex self.queues = queues self.validate_queues() self._exc_handlers = [] self.default_result_ttl = default_result_ttl self.default_worker_ttl = default_worker_ttl self.job_monitoring_interval = job_monitoring_interval self._state = 'starting' self._is_horse = False self._horse_pid = 0 self._stop_requested = False self.log = logger self.log_job_description = log_job_description self.last_cleaned_at = None self.successful_job_count = 0 self.failed_job_count = 0 self.total_working_time = 0 self.birth_date = None self.scheduler = None self.pubsub = None self.pubsub_thread = None self.disable_default_exception_handler = disable_default_exception_handler if isinstance(exception_handlers, (list, tuple)): for handler in exception_handlers: self.push_exc_handler(handler) elif exception_handlers is not None: self.push_exc_handler(exception_handlers) def get_redis_server_version(self): """Return Redis server version of connection""" if not self.redis_server_version: self.redis_server_version = get_version(self.connection) return self.redis_server_version def validate_queues(self): """Sanity check for the given queues.""" for queue in self.queues: if not isinstance(queue, self.queue_class): raise TypeError('{0} is not of type {1} or string types'.format(queue, self.queue_class)) def queue_names(self): """Returns the queue names of this worker's queues.""" return [queue.name for queue in self.queues] def queue_keys(self): """Returns the Redis keys representing this worker's queues.""" return [queue.key for queue in self.queues] @property def key(self): """Returns the worker's Redis hash key.""" return self.redis_worker_namespace_prefix + self.name @property def pubsub_channel_name(self): """Returns the worker's Redis hash key.""" return PUBSUB_CHANNEL_TEMPLATE % self.name @property def horse_pid(self): """The horse's process ID. Only available in the worker. Will return 0 in the horse part of the fork. """ return self._horse_pid @property def is_horse(self): """Returns whether or not this is the worker or the work horse.""" return self._is_horse def procline(self, message): """Changes the current procname for the process. This can be used to make `ps -ef` output more readable. """ setprocname('rq: {0}'.format(message)) def register_birth(self): """Registers its own birth.""" self.log.debug('Registering birth of worker %s', self.name) if self.connection.exists(self.key) and \ not self.connection.hexists(self.key, 'death'): msg = 'There exists an active worker named {0!r} already' raise ValueError(msg.format(self.name)) key = self.key queues = ','.join(self.queue_names()) with self.connection.pipeline() as p: p.delete(key) now = utcnow() now_in_string = utcformat(now) self.birth_date = now mapping={ 'birth': now_in_string, 'last_heartbeat': now_in_string, 'queues': queues, 'pid': self.pid, 'hostname': self.hostname, 'version': self.version, 'python_version': self.python_version, } if self.get_redis_server_version() >= StrictVersion("4.0.0"): p.hset(key, mapping=mapping) else: p.hmset(key, mapping) worker_registration.register(self, p) p.expire(key, self.default_worker_ttl + 60) p.execute() def register_death(self): """Registers its own death.""" self.log.debug('Registering death') with self.connection.pipeline() as p: # We cannot use self.state = 'dead' here, because that would # rollback the pipeline worker_registration.unregister(self, p) p.hset(self.key, 'death', utcformat(utcnow())) p.expire(self.key, 60) p.execute() def set_shutdown_requested_date(self): """Sets the date on which the worker received a (warm) shutdown request""" self.connection.hset(self.key, 'shutdown_requested_date', utcformat(utcnow())) # @property # def birth_date(self): # """Fetches birth date from Redis.""" # birth_timestamp = self.connection.hget(self.key, 'birth') # if birth_timestamp is not None: # return utcparse(as_text(birth_timestamp)) @property def shutdown_requested_date(self): """Fetches shutdown_requested_date from Redis.""" shutdown_requested_timestamp = self.connection.hget(self.key, 'shutdown_requested_date') if shutdown_requested_timestamp is not None: return utcparse(as_text(shutdown_requested_timestamp)) @property def death_date(self): """Fetches death date from Redis.""" death_timestamp = self.connection.hget(self.key, 'death') if death_timestamp is not None: return utcparse(as_text(death_timestamp)) def set_state(self, state, pipeline=None): self._state = state connection = pipeline if pipeline is not None else self.connection connection.hset(self.key, 'state', state) def _set_state(self, state): """Raise a DeprecationWarning if ``worker.state = X`` is used""" warnings.warn( "worker.state is deprecated, use worker.set_state() instead.", DeprecationWarning ) self.set_state(state) def get_state(self): return self._state def _get_state(self): """Raise a DeprecationWarning if ``worker.state == X`` is used""" warnings.warn( "worker.state is deprecated, use worker.get_state() instead.", DeprecationWarning ) return self.get_state() state = property(_get_state, _set_state) def set_current_job_id(self, job_id, pipeline=None): connection = pipeline if pipeline is not None else self.connection if job_id is None: connection.hdel(self.key, 'current_job') else: connection.hset(self.key, 'current_job', job_id) def get_current_job_id(self, pipeline=None): connection = pipeline if pipeline is not None else self.connection return as_text(connection.hget(self.key, 'current_job')) def get_current_job(self): """Returns the job id of the currently executing job.""" job_id = self.get_current_job_id() if job_id is None: return None return self.job_class.fetch(job_id, self.connection, self.serializer) def _install_signal_handlers(self): """Installs signal handlers for handling SIGINT and SIGTERM gracefully. """ signal.signal(signal.SIGINT, self.request_stop) signal.signal(signal.SIGTERM, self.request_stop) def kill_horse(self, sig=SIGKILL): """ Kill the horse but catch "No such process" error has the horse could already be dead. """ try: os.killpg(os.getpgid(self.horse_pid), sig) self.log.info('Killed horse pid %s', self.horse_pid) except OSError as e: if e.errno == errno.ESRCH: # "No such process" is fine with us self.log.debug('Horse already dead') else: raise def wait_for_horse(self): """ A waiting the end of the horse process and recycling resources. """ pid = None stat = None try: pid, stat = os.waitpid(self.horse_pid, 0) except ChildProcessError as e: # ChildProcessError: [Errno 10] No child processes pass return pid, stat def request_force_stop(self, signum, frame): """Terminates the application (cold shutdown). """ self.log.warning('Cold shut down') # Take down the horse with the worker if self.horse_pid: self.log.debug('Taking down horse %s with me', self.horse_pid) self.kill_horse() self.wait_for_horse() raise SystemExit() def request_stop(self, signum, frame): """Stops the current worker loop but waits for child processes to end gracefully (warm shutdown). """ self.log.debug('Got signal %s', signal_name(signum)) signal.signal(signal.SIGINT, self.request_force_stop) signal.signal(signal.SIGTERM, self.request_force_stop) self.handle_warm_shutdown_request() self._shutdown() def _shutdown(self): """ If shutdown is requested in the middle of a job, wait until finish before shutting down and save the request in redis """ if self.get_state() == WorkerStatus.BUSY: self._stop_requested = True self.set_shutdown_requested_date() self.log.debug('Stopping after current horse is finished. ' 'Press Ctrl+C again for a cold shutdown.') if self.scheduler: self.stop_scheduler() else: if self.scheduler: self.stop_scheduler() raise StopRequested() def handle_warm_shutdown_request(self): self.log.info('Warm shut down requested') def check_for_suspension(self, burst): """Check to see if workers have been suspended by `rq suspend`""" before_state = None notified = False while not self._stop_requested and is_suspended(self.connection, self): if burst: self.log.info('Suspended in burst mode, exiting') self.log.info('Note: There could still be unfinished jobs on the queue') raise StopRequested if not notified: self.log.info('Worker suspended, run `rq resume` to resume') before_state = self.get_state() self.set_state(WorkerStatus.SUSPENDED) notified = True time.sleep(1) if before_state: self.set_state(before_state) def run_maintenance_tasks(self): """ Runs periodic maintenance tasks, these include: 1. Check if scheduler should be started. This check should not be run on first run since worker.work() already calls `scheduler.enqueue_scheduled_jobs()` on startup. 2. Cleaning registries """ # No need to try to start scheduler on first run if self.last_cleaned_at: if self.scheduler and not self.scheduler._process: self.scheduler.acquire_locks(auto_start=True) self.clean_registries() def subscribe(self): """Subscribe to this worker's channel""" self.log.info('Subscribing to channel %s', self.pubsub_channel_name) self.pubsub = self.connection.pubsub() self.pubsub.subscribe(**{self.pubsub_channel_name: self.handle_payload}) self.pubsub_thread = self.pubsub.run_in_thread(sleep_time=0.2) def unsubscribe(self): """Unsubscribe from pubsub channel""" if self.pubsub_thread: self.log.info('Unsubscribing from channel %s', self.pubsub_channel_name) self.pubsub_thread.stop() self.pubsub_thread.join() self.pubsub.unsubscribe() self.pubsub.close() def work(self, burst=False, logging_level="INFO", date_format=DEFAULT_LOGGING_DATE_FORMAT, log_format=DEFAULT_LOGGING_FORMAT, max_jobs=None, with_scheduler=False): """Starts the work loop. Pops and performs all jobs on the current list of queues. When all queues are empty, block and wait for new jobs to arrive on any of the queues, unless `burst` mode is enabled. The return value indicates whether any jobs were processed. """ setup_loghandlers(logging_level, date_format, log_format) completed_jobs = 0 self.register_birth() self.log.info("Worker %s: started, version %s", self.key, VERSION) self.subscribe() self.set_state(WorkerStatus.STARTED) qnames = self.queue_names() self.log.info('*** Listening on %s...', green(', '.join(qnames))) if with_scheduler: self.scheduler = RQScheduler( self.queues, connection=self.connection, logging_level=logging_level, date_format=date_format, log_format=log_format) self.scheduler.acquire_locks() # If lock is acquired, start scheduler if self.scheduler.acquired_locks: # If worker is run on burst mode, enqueue_scheduled_jobs() # before working. Otherwise, start scheduler in a separate process if burst: self.scheduler.enqueue_scheduled_jobs() self.scheduler.release_locks() else: self.scheduler.start() self._install_signal_handlers() try: while True: try: self.check_for_suspension(burst) if self.should_run_maintenance_tasks: self.run_maintenance_tasks() if self._stop_requested: self.log.info('Worker %s: stopping on request', self.key) break timeout = None if burst else max(1, self.default_worker_ttl - 15) result = self.dequeue_job_and_maintain_ttl(timeout) if result is None: if burst: self.log.info("Worker %s: done, quitting", self.key) break job, queue = result self.execute_job(job, queue) self.heartbeat() completed_jobs += 1 if max_jobs is not None: if completed_jobs >= max_jobs: self.log.info( "Worker %s: finished executing %d jobs, quitting", self.key, completed_jobs ) break except StopRequested: break except SystemExit: # Cold shutdown detected raise except: # noqa self.log.error( 'Worker %s: found an unhandled exception, quitting...', self.key, exc_info=True ) break finally: if not self.is_horse: if self.scheduler: self.stop_scheduler() self.register_death() self.unsubscribe() return bool(completed_jobs) def stop_scheduler(self): """Ensure scheduler process is stopped""" if self.scheduler._process and self.scheduler._process.pid: # Send the kill signal to scheduler process try: os.kill(self.scheduler._process.pid, signal.SIGTERM) except OSError: pass self.scheduler._process.join() def dequeue_job_and_maintain_ttl(self, timeout): result = None qnames = ','.join(self.queue_names()) self.set_state(WorkerStatus.IDLE) self.procline('Listening on ' + qnames) self.log.debug('*** Listening on %s...', green(qnames)) while True: self.heartbeat() if self.should_run_maintenance_tasks: self.run_maintenance_tasks() try: result = self.queue_class.dequeue_any(self.queues, timeout, connection=self.connection, job_class=self.job_class, serializer=self.serializer) if result is not None: job, queue = result job.redis_server_version = self.get_redis_server_version() if self.log_job_description: self.log.info( '%s: %s (%s)', green(queue.name), blue(job.description), job.id) else: self.log.info('%s: %s', green(queue.name), job.id) break except DequeueTimeout: pass self.heartbeat() return result def heartbeat(self, timeout=None, pipeline=None): """Specifies a new worker timeout, typically by extending the expiration time of the worker, effectively making this a "heartbeat" to not expire the worker until the timeout passes. The next heartbeat should come before this time, or the worker will die (at least from the monitoring dashboards). If no timeout is given, the default_worker_ttl will be used to update the expiration time of the worker. """ timeout = timeout or self.default_worker_ttl + 60 connection = pipeline if pipeline is not None else self.connection connection.expire(self.key, timeout) connection.hset(self.key, 'last_heartbeat', utcformat(utcnow())) self.log.debug('Sent heartbeat to prevent worker timeout. ' 'Next one should arrive within %s seconds.', timeout) def refresh(self): data = self.connection.hmget( self.key, 'queues', 'state', 'current_job', 'last_heartbeat', 'birth', 'failed_job_count', 'successful_job_count', 'total_working_time', 'hostname', 'pid', 'version', 'python_version', ) (queues, state, job_id, last_heartbeat, birth, failed_job_count, successful_job_count, total_working_time, hostname, pid, version, python_version) = data queues = as_text(queues) self.hostname = as_text(hostname) self.pid = int(pid) if pid else None self.version = as_text(version) self.python_version = as_text(python_version) self._state = as_text(state or '?') self._job_id = job_id or None if last_heartbeat: self.last_heartbeat = utcparse(as_text(last_heartbeat)) else: self.last_heartbeat = None if birth: self.birth_date = utcparse(as_text(birth)) else: self.birth_date = None if failed_job_count: self.failed_job_count = int(as_text(failed_job_count)) if successful_job_count: self.successful_job_count = int(as_text(successful_job_count)) if total_working_time: self.total_working_time = float(as_text(total_working_time)) if queues: self.queues = [self.queue_class(queue, connection=self.connection, job_class=self.job_class, serializer=self.serializer) for queue in queues.split(',')] def increment_failed_job_count(self, pipeline=None): connection = pipeline if pipeline is not None else self.connection connection.hincrby(self.key, 'failed_job_count', 1) def increment_successful_job_count(self, pipeline=None): connection = pipeline if pipeline is not None else self.connection connection.hincrby(self.key, 'successful_job_count', 1) def increment_total_working_time(self, job_execution_time, pipeline): pipeline.hincrbyfloat(self.key, 'total_working_time', job_execution_time.total_seconds()) def fork_work_horse(self, job, queue): """Spawns a work horse to perform the actual work and passes it a job. """ child_pid = os.fork() os.environ['RQ_WORKER_ID'] = self.name os.environ['RQ_JOB_ID'] = job.id if child_pid == 0: os.setsid() self.main_work_horse(job, queue) os._exit(0) # just in case else: self._horse_pid = child_pid self.procline('Forked {0} at {1}'.format(child_pid, time.time())) def monitor_work_horse(self, job, queue): """The worker will monitor the work horse and make sure that it either executes successfully or the status of the job is set to failed """ ret_val = None job.started_at = utcnow() while True: try: with UnixSignalDeathPenalty(self.job_monitoring_interval, HorseMonitorTimeoutException): retpid, ret_val = self.wait_for_horse() break except HorseMonitorTimeoutException: # Horse has not exited yet and is still running. # Send a heartbeat to keep the worker alive. # Kill the job from this side if something is really wrong (interpreter lock/etc). if job.timeout != -1 and (utcnow() - job.started_at).total_seconds() > (job.timeout + 60): self.heartbeat(self.job_monitoring_interval + 60) self.kill_horse() self.wait_for_horse() break with self.connection.pipeline() as pipeline: self.heartbeat(self.job_monitoring_interval + 60, pipeline=pipeline) job.heartbeat(utcnow(), pipeline=pipeline) pipeline.execute() except OSError as e: # In case we encountered an OSError due to EINTR (which is # caused by a SIGINT or SIGTERM signal during # os.waitpid()), we simply ignore it and enter the next # iteration of the loop, waiting for the child to end. In # any other case, this is some other unexpected OS error, # which we don't want to catch, so we re-raise those ones. if e.errno != errno.EINTR: raise # Send a heartbeat to keep the worker alive. self.heartbeat() self._horse_pid = 0 # Set horse PID to 0, horse has finished working if ret_val == os.EX_OK: # The process exited normally. return job_status = job.get_status() if job_status is None: # Job completed and its ttl has expired return if job_status not in [JobStatus.FINISHED, JobStatus.FAILED]: if not job.ended_at: job.ended_at = utcnow() # Unhandled failure: move the job to the failed queue self.log.warning(( 'Moving job to FailedJobRegistry ' '(work-horse terminated unexpectedly; waitpid returned {})' ).format(ret_val)) self.handle_job_failure( job, queue=queue, exc_string="Work-horse was terminated unexpectedly " "(waitpid returned %s)" % ret_val ) def execute_job(self, job, queue): """Spawns a work horse to perform the actual work and passes it a job. The worker will wait for the work horse and make sure it executes within the given timeout bounds, or will end the work horse with SIGALRM. """ self.set_state(WorkerStatus.BUSY) self.fork_work_horse(job, queue) self.monitor_work_horse(job, queue) self.set_state(WorkerStatus.IDLE) def main_work_horse(self, job, queue): """This is the entry point of the newly spawned work horse.""" # After fork()'ing, always assure we are generating random sequences # that are different from the worker. random.seed() self.setup_work_horse_signals() self._is_horse = True self.log = logger try: self.perform_job(job, queue) except: os._exit(1) # os._exit() is the way to exit from childs after a fork(), in # contrast to the regular sys.exit() os._exit(0) def setup_work_horse_signals(self): """Setup signal handing for the newly spawned work horse.""" # Always ignore Ctrl+C in the work horse, as it might abort the # currently running job. # The main worker catches the Ctrl+C and requests graceful shutdown # after the current work is done. When cold shutdown is requested, it # kills the current job anyway. signal.signal(signal.SIGINT, signal.SIG_IGN) signal.signal(signal.SIGTERM, signal.SIG_DFL) def prepare_job_execution(self, job, heartbeat_ttl=None): """Performs misc bookkeeping like updating states prior to job execution. """ if job.timeout == -1: timeout = -1 else: timeout = job.timeout or 180 if heartbeat_ttl is None: heartbeat_ttl = self.job_monitoring_interval + 60 with self.connection.pipeline() as pipeline: self.set_state(WorkerStatus.BUSY, pipeline=pipeline) self.set_current_job_id(job.id, pipeline=pipeline) self.heartbeat(heartbeat_ttl, pipeline=pipeline) registry = StartedJobRegistry(job.origin, self.connection, job_class=self.job_class) registry.add(job, timeout, pipeline=pipeline) job.prepare_for_execution(self.name, pipeline=pipeline) pipeline.execute() msg = 'Processing {0} from {1} since {2}' self.procline(msg.format(job.func_name, job.origin, time.time())) def handle_job_failure(self, job, queue, started_job_registry=None, exc_string=''): """Handles the failure or an executing job by: 1. Setting the job status to failed 2. Removing the job from StartedJobRegistry 3. Setting the workers current job to None 4. Add the job to FailedJobRegistry """ self.log.debug('Handling failed execution of job %s', job.id) with self.connection.pipeline() as pipeline: if started_job_registry is None: started_job_registry = StartedJobRegistry( job.origin, self.connection, job_class=self.job_class ) job.worker_name = None # Requeue/reschedule if retry is configured if job.retries_left and job.retries_left > 0: retry = True retry_interval = job.get_retry_interval() job.retries_left = job.retries_left - 1 else: retry = False job.set_status(JobStatus.FAILED, pipeline=pipeline) started_job_registry.remove(job, pipeline=pipeline) if not self.disable_default_exception_handler and not retry: failed_job_registry = FailedJobRegistry(job.origin, job.connection, job_class=self.job_class) failed_job_registry.add(job, ttl=job.failure_ttl, exc_string=exc_string, pipeline=pipeline) self.set_current_job_id(None, pipeline=pipeline) self.increment_failed_job_count(pipeline) if job.started_at and job.ended_at: self.increment_total_working_time( job.ended_at - job.started_at, pipeline ) if retry: if retry_interval: scheduled_datetime = datetime.now(timezone.utc) + timedelta(seconds=retry_interval) job.set_status(JobStatus.SCHEDULED) queue.schedule_job(job, scheduled_datetime, pipeline=pipeline) else: queue.enqueue_job(job, pipeline=pipeline) try: pipeline.execute() except Exception: # Ensure that custom exception handlers are called # even if Redis is down pass def handle_job_success(self, job, queue, started_job_registry): self.log.debug('Handling successful execution of job %s', job.id) with self.connection.pipeline() as pipeline: while True: try: # if dependencies are inserted after enqueue_dependents # a WatchError is thrown by execute() pipeline.watch(job.dependents_key) # enqueue_dependents calls multi() on the pipeline! queue.enqueue_dependents(job, pipeline=pipeline) self.set_current_job_id(None, pipeline=pipeline) self.increment_successful_job_count(pipeline=pipeline) self.increment_total_working_time( job.ended_at - job.started_at, pipeline ) result_ttl = job.get_result_ttl(self.default_result_ttl) if result_ttl != 0: job.set_status(JobStatus.FINISHED, pipeline=pipeline) job.worker_name = None # Don't clobber the user's meta dictionary! job.save(pipeline=pipeline, include_meta=False) finished_job_registry = queue.finished_job_registry finished_job_registry.add(job, result_ttl, pipeline) job.cleanup(result_ttl, pipeline=pipeline, remove_from_queue=False) started_job_registry.remove(job, pipeline=pipeline) pipeline.execute() break except WatchError: continue def perform_job(self, job, queue, heartbeat_ttl=None): """Performs the actual work of a job. Will/should only be called inside the work horse's process. """ push_connection(self.connection) started_job_registry = queue.started_job_registry try: self.prepare_job_execution(job, heartbeat_ttl) job.started_at = utcnow() timeout = job.timeout or self.queue_class.DEFAULT_TIMEOUT with self.death_penalty_class(timeout, JobTimeoutException, job_id=job.id): rv = job.perform() job.ended_at = utcnow() # Pickle the result in the same try-except block since we need # to use the same exc handling when pickling fails job._result = rv self.handle_job_success(job=job, queue=queue, started_job_registry=started_job_registry) except: # NOQA job.ended_at = utcnow() exc_info = sys.exc_info() exc_string = ''.join(traceback.format_exception(*exc_info)) self.handle_job_failure(job=job, exc_string=exc_string, queue=queue, started_job_registry=started_job_registry) self.handle_exception(job, *exc_info) return False finally: pop_connection() self.log.info('%s: %s (%s)', green(job.origin), blue('Job OK'), job.id) if rv is not None: log_result = "{0!r}".format(as_text(text_type(rv))) self.log.debug('Result: %s', yellow(log_result)) if self.log_result_lifespan: result_ttl = job.get_result_ttl(self.default_result_ttl) if result_ttl == 0: self.log.info('Result discarded immediately') elif result_ttl > 0: self.log.info('Result is kept for %s seconds', result_ttl) else: self.log.info('Result will never expire, clean up result key manually') return True def handle_exception(self, job, *exc_info): """Walks the exception handler stack to delegate exception handling.""" exc_string = ''.join(traceback.format_exception(*exc_info)) self.log.error(exc_string, exc_info=True, extra={ 'func': job.func_name, 'arguments': job.args, 'kwargs': job.kwargs, 'queue': job.origin, 'job_id': job.id, }) for handler in self._exc_handlers: self.log.debug('Invoking exception handler %s', handler) fallthrough = handler(job, *exc_info) # Only handlers with explicit return values should disable further # exc handling, so interpret a None return value as True. if fallthrough is None: fallthrough = True if not fallthrough: break def push_exc_handler(self, handler_func): """Pushes an exception handler onto the exc handler stack.""" self._exc_handlers.append(handler_func) def pop_exc_handler(self): """Pops the latest exception handler off of the exc handler stack.""" return self._exc_handlers.pop() def __eq__(self, other): """Equality does not take the database/connection into account""" if not isinstance(other, self.__class__): raise TypeError('Cannot compare workers to other types (of workers)') return self.name == other.name def __hash__(self): """The hash does not take the database/connection into account""" return hash(self.name) def clean_registries(self): """Runs maintenance jobs on each Queue's registries.""" for queue in self.queues: # If there are multiple workers running, we only want 1 worker # to run clean_registries(). if queue.acquire_cleaning_lock(): self.log.info('Cleaning registries for queue: %s', queue.name) clean_registries(queue) clean_worker_registry(queue) self.last_cleaned_at = utcnow() @property def should_run_maintenance_tasks(self): """Maintenance tasks should run on first startup or every 10 minutes.""" if self.last_cleaned_at is None: return True if (utcnow() - self.last_cleaned_at) > timedelta(minutes=10): return True return False def handle_payload(self, message): """Handle external commands""" self.log.debug('Received message: %s', message) payload = parse_payload(message) handle_command(self, payload) class SimpleWorker(Worker): def execute_job(self, job, queue): """Execute job in same thread/process, do not fork()""" # "-1" means that jobs never timeout. In this case, we should _not_ do -1 + 60 = 59. We should just stick to DEFAULT_WORKER_TTL. if job.timeout == -1: timeout = DEFAULT_WORKER_TTL else: timeout = (job.timeout or DEFAULT_WORKER_TTL) + 60 return self.perform_job(job, queue, heartbeat_ttl=timeout) class HerokuWorker(Worker): """ Modified version of rq worker which: * stops work horses getting killed with SIGTERM * sends SIGRTMIN to work horses on SIGTERM to the main process which in turn causes the horse to crash `imminent_shutdown_delay` seconds later """ imminent_shutdown_delay = 6 frame_properties = ['f_code', 'f_lasti', 'f_lineno', 'f_locals', 'f_trace'] def setup_work_horse_signals(self): """Modified to ignore SIGINT and SIGTERM and only handle SIGRTMIN""" signal.signal(signal.SIGRTMIN, self.request_stop_sigrtmin) signal.signal(signal.SIGINT, signal.SIG_IGN) signal.signal(signal.SIGTERM, signal.SIG_IGN) def handle_warm_shutdown_request(self): """If horse is alive send it SIGRTMIN""" if self.horse_pid != 0: self.log.info( 'Worker %s: warm shut down requested, sending horse SIGRTMIN signal', self.key ) self.kill_horse(sig=signal.SIGRTMIN) else: self.log.warning('Warm shut down requested, no horse found') def request_stop_sigrtmin(self, signum, frame): if self.imminent_shutdown_delay == 0: self.log.warning('Imminent shutdown, raising ShutDownImminentException immediately') self.request_force_stop_sigrtmin(signum, frame) else: self.log.warning('Imminent shutdown, raising ShutDownImminentException in %d seconds', self.imminent_shutdown_delay) signal.signal(signal.SIGRTMIN, self.request_force_stop_sigrtmin) signal.signal(signal.SIGALRM, self.request_force_stop_sigrtmin) signal.alarm(self.imminent_shutdown_delay) def request_force_stop_sigrtmin(self, signum, frame): info = dict((attr, getattr(frame, attr)) for attr in self.frame_properties) self.log.warning('raising ShutDownImminentException to cancel job...') raise ShutDownImminentException('shut down imminent (signal: %s)' % signal_name(signum), info)