def _handle_success(ns, q, lock):
qb.set_state(app_name=ns.app_name, job_id=ns.job_id, completed=True)
q.consume()
lock.release()
log.info("successfully completed job",
extra=dict(app_name=ns.app_name, job_id=ns.job_id,
completed=True))
def _handle_success(ns, q, lock):
qb.set_state(
app_name=ns.app_name, job_id=ns.job_id, completed=True)
q.consume()
lock.release()
log.info(
"successfully completed job",
extra=dict(app_name=ns.app_name, job_id=ns.job_id, completed=True))
def _send_to_back_of_queue(q, app_name, job_id):
# this exists so un-runnable tasks don't hog the front of the queue
# and soak up resources
try:
qb.readd_subtask(app_name, job_id, _force=True)
q.consume()
log.info("Job sent to back of queue",
extra=dict(app_name=app_name, job_id=job_id))
except exceptions.JobAlreadyQueued:
log.info("Job already queued. Cannot send to back of queue.",
extra=dict(app_name=app_name, job_id=job_id))
def _send_to_back_of_queue(q, app_name, job_id):
# this exists so un-runnable tasks don't hog the front of the queue
# and soak up resources
try:
qb.readd_subtask(app_name, job_id, _force=True)
q.consume()
log.info(
"Job sent to back of queue",
extra=dict(app_name=app_name, job_id=job_id))
except exceptions.JobAlreadyQueued:
log.info(
"Job already queued. Cannot send to back of queue.",
extra=dict(app_name=app_name, job_id=job_id))
def validate_job_id(app_name, job_id, q, timeout):
"""Return True if valid job_id.
If invalid, do whatever cleanup for this job is necessary and return False.
--> necessary cleanup may include removing this job_id from queue
"""
if job_id is None:
log.info('No jobs found in %d seconds...' % timeout,
extra=dict(app_name=app_name))
return False
try:
dt.parse_job_id(app_name, job_id)
except exceptions.InvalidJobId as err:
log.error(
("Stolos found an invalid job_id. Removing it from queue"
" and marking that job_id as failed. Error details: %s") % err,
extra=dict(app_name=app_name, job_id=job_id))
q.consume()
qb._set_state_unsafe(app_name, job_id, failed=True)
return False
return True
def validate_job_id(app_name, job_id, q, timeout):
"""Return True if valid job_id.
If invalid, do whatever cleanup for this job is necessary and return False.
--> necessary cleanup may include removing this job_id from queue
"""
if job_id is None:
log.info('No jobs found in %d seconds...' % timeout, extra=dict(
app_name=app_name))
return False
try:
dt.parse_job_id(app_name, job_id)
except exceptions.InvalidJobId as err:
log.error((
"Stolos found an invalid job_id. Removing it from queue"
" and marking that job_id as failed. Error details: %s") % err,
extra=dict(app_name=app_name, job_id=job_id))
q.consume()
qb._set_state_unsafe(
app_name, job_id, failed=True)
return False
return True
def main(ns):
"""
Fetch a job_id from the `app_name` queue and figure out what to with it.
If the job is runnable, execute it and then queue its children into their
respective queues. If it's not runnable, queue its parents into respective
parent queues and remove the job from its own queue.
If the job fails, either requeue it or mark it as permanently failed
"""
assert ns.app_name in dt.get_task_names()
if ns.bypass_scheduler:
log.info(
"Running a task without scheduling anything"
" or fetching from a queue", extra=dict(
app_name=ns.app_name, job_id=ns.job_id))
assert ns.job_id
ns.job_type_func(ns=ns)
return
log.info("Beginning Stolos", extra=dict(**ns.__dict__))
q = qb.get_qbclient().LockingQueue(ns.app_name)
if ns.job_id:
lock = _handle_manually_given_job_id(ns)
q.consume = object # do nothing
else:
ns.job_id = q.get(timeout=ns.timeout)
if not validate_job_id(app_name=ns.app_name, job_id=ns.job_id,
q=q, timeout=ns.timeout):
return
try:
lock = get_lock_if_job_is_runnable(
app_name=ns.app_name, job_id=ns.job_id)
except exceptions.NoNodeError:
q.consume()
log.exception(
"Job failed. The job is queued, so why does its state not"
" exist? The Queue backend may be in an inconsistent state."
" Consuming this job",
extra=dict(app_name=ns.app_name, job_id=ns.job_id))
return
log.debug(
"Stolos got a job_id.", extra=dict(
app_name=ns.app_name, job_id=ns.job_id, acquired_lock=bool(lock)))
if lock is False:
# infinite loop: some jobs will always requeue if lock is unobtainable
log.info("Could not obtain a lock. Will requeue and try again later",
extra=dict(app_name=ns.app_name, job_id=ns.job_id))
_send_to_back_of_queue(
q=q, app_name=ns.app_name, job_id=ns.job_id)
return
if not parents_completed(ns.app_name, ns.job_id, q=q, lock=lock):
return
log.info(
"Job starting!", extra=dict(app_name=ns.app_name, job_id=ns.job_id))
try:
ns.job_type_func(ns=ns)
except exceptions.CodeError: # assume error is previously logged
_handle_failure(ns, q, lock)
return
except Exception as err:
log.exception(
("Job failed! Unhandled exception in an application!"
" Fix ASAP because"
" it is unclear how to handle this failure. %s: %s")
% (err.__class__.__name__, err), extra=dict(
app_name=ns.app_name, job_id=ns.job_id, failed=True))
return
_handle_success(ns, q, lock)
def main(ns):
"""
Fetch a job_id from the `app_name` queue and figure out what to with it.
If the job is runnable, execute it and then queue its children into their
respective queues. If it's not runnable, queue its parents into respective
parent queues and remove the job from its own queue.
If the job fails, either requeue it or mark it as permanently failed
"""
assert ns.app_name in dt.get_task_names()
if ns.bypass_scheduler:
log.info(
"Running a task without scheduling anything"
" or fetching from a queue",
extra=dict(app_name=ns.app_name, job_id=ns.job_id))
assert ns.job_id
ns.job_type_func(ns=ns)
return
log.info("Beginning Stolos", extra=dict(**ns.__dict__))
q = qb.get_qbclient().LockingQueue(ns.app_name)
if ns.job_id:
lock = _handle_manually_given_job_id(ns)
q.consume = object # do nothing
else:
ns.job_id = q.get(timeout=ns.timeout)
if not validate_job_id(
app_name=ns.app_name, job_id=ns.job_id, q=q,
timeout=ns.timeout):
return
try:
lock = get_lock_if_job_is_runnable(app_name=ns.app_name,
job_id=ns.job_id)
except exceptions.NoNodeError:
q.consume()
log.exception(
"Job failed. The job is queued, so why does its state not"
" exist? The Queue backend may be in an inconsistent state."
" Consuming this job",
extra=dict(app_name=ns.app_name, job_id=ns.job_id))
return
log.debug("Stolos got a job_id.",
extra=dict(app_name=ns.app_name,
job_id=ns.job_id,
acquired_lock=bool(lock)))
if lock is False:
# infinite loop: some jobs will always requeue if lock is unobtainable
log.info("Could not obtain a lock. Will requeue and try again later",
extra=dict(app_name=ns.app_name, job_id=ns.job_id))
_send_to_back_of_queue(q=q, app_name=ns.app_name, job_id=ns.job_id)
return
if not parents_completed(ns.app_name, ns.job_id, q=q, lock=lock):
return
log.info("Job starting!",
extra=dict(app_name=ns.app_name, job_id=ns.job_id))
try:
ns.job_type_func(ns=ns)
except exceptions.CodeError: # assume error is previously logged
_handle_failure(ns, q, lock)
return
except Exception as err:
log.exception(("Job failed! Unhandled exception in an application!"
" Fix ASAP because"
" it is unclear how to handle this failure. %s: %s") %
(err.__class__.__name__, err),
extra=dict(app_name=ns.app_name,
job_id=ns.job_id,
failed=True))
return
_handle_success(ns, q, lock)
