#
#
# Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Google Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.
"""Module implementing the job queue handling.
Locking: there's a single, large lock in the L{JobQueue} class. It's
used by all other classes in this module.
@var JOBQUEUE_THREADS: the number of worker threads we start for
processing jobs
"""
import logging
import errno
import time
import weakref
import threading
import itertools
try:
# pylint: disable=E0611
from pyinotify import pyinotify
except ImportError:
import pyinotify
from ganeti import asyncnotifier
from ganeti import constants
from ganeti import serializer
from ganeti import workerpool
from ganeti import locking
from ganeti import opcodes
from ganeti import errors
from ganeti import mcpu
from ganeti import utils
from ganeti import jstore
from ganeti import rpc
from ganeti import runtime
from ganeti import netutils
from ganeti import compat
from ganeti import ht
from ganeti import query
from ganeti import qlang
JOBQUEUE_THREADS = 25
JOBS_PER_ARCHIVE_DIRECTORY = 10000
# member lock names to be passed to @ssynchronized decorator
_LOCK = "_lock"
_QUEUE = "_queue"
class CancelJob(Exception):
"""Special exception to cancel a job.
"""
def TimeStampNow():
"""Returns the current timestamp.
@rtype: tuple
@return: the current time in the (seconds, microseconds) format
"""
return utils.SplitTime(time.time())
class _SimpleJobQuery:
"""Wrapper for job queries.
Instance keeps list of fields cached, useful e.g. in L{_JobChangesChecker}.
"""
def __init__(self, fields):
"""Initializes this class.
"""
self._query = query.Query(query.JOB_FIELDS, fields)
def __call__(self, job):
"""Executes a job query using cached field list.
"""
return self._query.OldStyleQuery([(job.id, job)], sort_by_name=False)[0]
class _QueuedOpCode(object):
"""Encapsulates an opcode object.
@ivar log: holds the execution log and consists of tuples
of the form C{(log_serial, timestamp, level, message)}
@ivar input: the OpCode we encapsulate
@ivar status: the current status
@ivar result: the result of the LU execution
@ivar start_timestamp: timestamp for the start of the execution
@ivar exec_timestamp: timestamp for the actual LU Exec() function invocation
@ivar stop_timestamp: timestamp for the end of the execution
"""
__slots__ = ["input", "status", "result", "log", "priority",
"start_timestamp", "exec_timestamp", "end_timestamp",
"__weakref__"]
def __init__(self, op):
"""Initializes instances of this class.
@type op: L{opcodes.OpCode}
@param op: the opcode we encapsulate
"""
self.input = op
self.status = constants.OP_STATUS_QUEUED
self.result = None
self.log = []
self.start_timestamp = None
self.exec_timestamp = None
self.end_timestamp = None
# Get initial priority (it might change during the lifetime of this opcode)
self.priority = getattr(op, "priority", constants.OP_PRIO_DEFAULT)
@classmethod
def Restore(cls, state):
"""Restore the _QueuedOpCode from the serialized form.
@type state: dict
@param state: the serialized state
@rtype: _QueuedOpCode
@return: a new _QueuedOpCode instance
"""
obj = _QueuedOpCode.__new__(cls)
obj.input = opcodes.OpCode.LoadOpCode(state["input"])
obj.status = state["status"]
obj.result = state["result"]
obj.log = state["log"]
obj.start_timestamp = state.get("start_timestamp", None)
obj.exec_timestamp = state.get("exec_timestamp", None)
obj.end_timestamp = state.get("end_timestamp", None)
obj.priority = state.get("priority", constants.OP_PRIO_DEFAULT)
return obj
def Serialize(self):
"""Serializes this _QueuedOpCode.
@rtype: dict
@return: the dictionary holding the serialized state
"""
return {
"input": self.input.__getstate__(),
"status": self.status,
"result": self.result,
"log": self.log,
"start_timestamp": self.start_timestamp,
"exec_timestamp": self.exec_timestamp,
"end_timestamp": self.end_timestamp,
"priority": self.priority,
}
class _QueuedJob(object):
"""In-memory job representation.
This is what we use to track the user-submitted jobs. Locking must
be taken care of by users of this class.
@type queue: L{JobQueue}
@ivar queue: the parent queue
@ivar id: the job ID
@type ops: list
@ivar ops: the list of _QueuedOpCode that constitute the job
@type log_serial: int
@ivar log_serial: holds the index for the next log entry
@ivar received_timestamp: the timestamp for when the job was received
@ivar start_timestmap: the timestamp for start of execution
@ivar end_timestamp: the timestamp for end of execution
@ivar writable: Whether the job is allowed to be modified
"""
# pylint: disable=W0212
__slots__ = ["queue", "id", "ops", "log_serial", "ops_iter", "cur_opctx",
"received_timestamp", "start_timestamp", "end_timestamp",
"__weakref__", "processor_lock", "writable"]
def __init__(self, queue, job_id, ops, writable):
"""Constructor for the _QueuedJob.
@type queue: L{JobQueue}
@param queue: our parent queue
@type job_id: job_id
@param job_id: our job id
@type ops: list
@param ops: the list of opcodes we hold, which will be encapsulated
in _QueuedOpCodes
@type writable: bool
@param writable: Whether job can be modified
"""
if not ops:
raise errors.GenericError("A job needs at least one opcode")
self.queue = queue
self.id = job_id
self.ops = [_QueuedOpCode(op) for op in ops]
self.log_serial = 0
self.received_timestamp = TimeStampNow()
self.start_timestamp = None
self.end_timestamp = None
self._InitInMemory(self, writable)
@staticmethod
def _InitInMemory(obj, writable):
"""Initializes in-memory variables.
"""
obj.writable = writable
obj.ops_iter = None
obj.cur_opctx = None
# Read-only jobs are not processed and therefore don't need a lock
if writable:
obj.processor_lock = threading.Lock()
else:
obj.processor_lock = None
def __repr__(self):
status = ["%s.%s" % (self.__class__.__module__, self.__class__.__name__),
"id=%s" % self.id,
"ops=%s" % ",".join([op.input.Summary() for op in self.ops])]
return "<%s at %#x>" % (" ".join(status), id(self))
@classmethod
def Restore(cls, queue, state, writable):
"""Restore a _QueuedJob from serialized state:
@type queue: L{JobQueue}
@param queue: to which queue the restored job belongs
@type state: dict
@param state: the serialized state
@type writable: bool
@param writable: Whether job can be modified
@rtype: _JobQueue
@return: the restored _JobQueue instance
"""
obj = _QueuedJob.__new__(cls)
obj.queue = queue
obj.id = state["id"]
obj.received_timestamp = state.get("received_timestamp", None)
obj.start_timestamp = state.get("start_timestamp", None)
obj.end_timestamp = state.get("end_timestamp", None)
obj.ops = []
obj.log_serial = 0
for op_state in state["ops"]:
op = _QueuedOpCode.Restore(op_state)
for log_entry in op.log:
obj.log_serial = max(obj.log_serial, log_entry[0])
obj.ops.append(op)
cls._InitInMemory(obj, writable)
return obj
def Serialize(self):
"""Serialize the _JobQueue instance.
@rtype: dict
@return: the serialized state
"""
return {
"id": self.id,
"ops": [op.Serialize() for op in self.ops],
"start_timestamp": self.start_timestamp,
"end_timestamp": self.end_timestamp,
"received_timestamp": self.received_timestamp,
}
def CalcStatus(self):
"""Compute the status of this job.
This function iterates over all the _QueuedOpCodes in the job and
based on their status, computes the job status.
The algorithm is:
- if we find a cancelled, or finished with error, the job
status will be the same
- otherwise, the last opcode with the status one of:
- waitlock
- canceling
- running
will determine the job status
- otherwise, it means either all opcodes are queued, or success,
and the job status will be the same
@return: the job status
"""
status = constants.JOB_STATUS_QUEUED
all_success = True
for op in self.ops:
if op.status == constants.OP_STATUS_SUCCESS:
continue
all_success = False
if op.status == constants.OP_STATUS_QUEUED:
pass
elif op.status == constants.OP_STATUS_WAITING:
status = constants.JOB_STATUS_WAITING
elif op.status == constants.OP_STATUS_RUNNING:
status = constants.JOB_STATUS_RUNNING
elif op.status == constants.OP_STATUS_CANCELING:
status = constants.JOB_STATUS_CANCELING
break
elif op.status == constants.OP_STATUS_ERROR:
status = constants.JOB_STATUS_ERROR
# The whole job fails if one opcode failed
break
elif op.status == constants.OP_STATUS_CANCELED:
status = constants.OP_STATUS_CANCELED
break
if all_success:
status = constants.JOB_STATUS_SUCCESS
return status
def CalcPriority(self):
"""Gets the current priority for this job.
Only unfinished opcodes are considered. When all are done, the default
priority is used.
@rtype: int
"""
priorities = [op.priority for op in self.ops
if op.status not in constants.OPS_FINALIZED]
if not priorities:
# All opcodes are done, assume default priority
return constants.OP_PRIO_DEFAULT
return min(priorities)
def GetLogEntries(self, newer_than):
"""Selectively returns the log entries.
@type newer_than: None or int
@param newer_than: if this is None, return all log entries,
otherwise return only the log entries with serial higher
than this value
@rtype: list
@return: the list of the log entries selected
"""
if newer_than is None:
serial = -1
else:
serial = newer_than
entries = []
for op in self.ops:
entries.extend(filter(lambda entry: entry[0] > serial, op.log))
return entries
def GetInfo(self, fields):
"""Returns information about a job.
@type fields: list
@param fields: names of fields to return
@rtype: list
@return: list with one element for each field
@raise errors.OpExecError: when an invalid field
has been passed
"""
return _SimpleJobQuery(fields)(self)
def MarkUnfinishedOps(self, status, result):
"""Mark unfinished opcodes with a given status and result.
This is an utility function for marking all running or waiting to
be run opcodes with a given status. Opcodes which are already
finalised are not changed.
@param status: a given opcode status
@param result: the opcode result
"""
not_marked = True
for op in self.ops:
if op.status in constants.OPS_FINALIZED:
assert not_marked, "Finalized opcodes found after non-finalized ones"
continue
op.status = status
op.result = result
not_marked = False
def Finalize(self):
"""Marks the job as finalized.
"""
self.end_timestamp = TimeStampNow()
def Cancel(self):
"""Marks job as canceled/-ing if possible.
@rtype: tuple; (bool, string)
@return: Boolean describing whether job was successfully canceled or marked
as canceling and a text message
"""
status = self.CalcStatus()
if status == constants.JOB_STATUS_QUEUED:
self.MarkUnfinishedOps(constants.OP_STATUS_CANCELED,
"Job canceled by request")
self.Finalize()
return (True, "Job %s canceled" % self.id)
elif status == constants.JOB_STATUS_WAITING:
# The worker will notice the new status and cancel the job
self.MarkUnfinishedOps(constants.OP_STATUS_CANCELING, None)
return (True, "Job %s will be canceled" % self.id)
else:
logging.debug("Job %s is no longer waiting in the queue", self.id)
return (False, "Job %s is no longer waiting in the queue" % self.id)
class _OpExecCallbacks(mcpu.OpExecCbBase):
def __init__(self, queue, job, op):
"""Initializes this class.
@type queue: L{JobQueue}
@param queue: Job queue
@type job: L{_QueuedJob}
@param job: Job object
@type op: L{_QueuedOpCode}
@param op: OpCode
"""
assert queue, "Queue is missing"
assert job, "Job is missing"
assert op, "Opcode is missing"
self._queue = queue
self._job = job
self._op = op
def _CheckCancel(self):
"""Raises an exception to cancel the job if asked to.
"""
# Cancel here if we were asked to
if self._op.status == constants.OP_STATUS_CANCELING:
logging.debug("Canceling opcode")
raise CancelJob()
@locking.ssynchronized(_QUEUE, shared=1)
def NotifyStart(self):
"""Mark the opcode as running, not lock-waiting.
This is called from the mcpu code as a notifier function, when the LU is
finally about to start the Exec() method. Of course, to have end-user
visible results, the opcode must be initially (before calling into
Processor.ExecOpCode) set to OP_STATUS_WAITING.
"""
assert self._op in self._job.ops
assert self._op.status in (constants.OP_STATUS_WAITING,
constants.OP_STATUS_CANCELING)
# Cancel here if we were asked to
self._CheckCancel()
logging.debug("Opcode is now running")
self._op.status = constants.OP_STATUS_RUNNING
self._op.exec_timestamp = TimeStampNow()
# And finally replicate the job status
self._queue.UpdateJobUnlocked(self._job)
@locking.ssynchronized(_QUEUE, shared=1)
def _AppendFeedback(self, timestamp, log_type, log_msg):
"""Internal feedback append function, with locks
"""
self._job.log_serial += 1
self._op.log.append((self._job.log_serial, timestamp, log_type, log_msg))
self._queue.UpdateJobUnlocked(self._job, replicate=False)
def Feedback(self, *args):
"""Append a log entry.
"""
assert len(args) < 3
if len(args) == 1:
log_type = constants.ELOG_MESSAGE
log_msg = args[0]
else:
(log_type, log_msg) = args
# The time is split to make serialization easier and not lose
# precision.
timestamp = utils.SplitTime(time.time())
self._AppendFeedback(timestamp, log_type, log_msg)
def CheckCancel(self):
"""Check whether job has been cancelled.
"""
assert self._op.status in (constants.OP_STATUS_WAITING,
constants.OP_STATUS_CANCELING)
# Cancel here if we were asked to
self._CheckCancel()
def SubmitManyJobs(self, jobs):
"""Submits jobs for processing.
See L{JobQueue.SubmitManyJobs}.
"""
# Locking is done in job queue
return self._queue.SubmitManyJobs(jobs)
class _JobChangesChecker(object):
def __init__(self, fields, prev_job_info, prev_log_serial):
"""Initializes this class.
@type fields: list of strings
@param fields: Fields requested by LUXI client
@type prev_job_info: string
@param prev_job_info: previous job info, as passed by the LUXI client
@type prev_log_serial: string
@param prev_log_serial: previous job serial, as passed by the LUXI client
"""
self._squery = _SimpleJobQuery(fields)
self._prev_job_info = prev_job_info
self._prev_log_serial = prev_log_serial
def __call__(self, job):
"""Checks whether job has changed.
@type job: L{_QueuedJob}
@param job: Job object
"""
assert not job.writable, "Expected read-only job"
status = job.CalcStatus()
job_info = self._squery(job)
log_entries = job.GetLogEntries(self._prev_log_serial)
# Serializing and deserializing data can cause type changes (e.g. from
# tuple to list) or precision loss. We're doing it here so that we get
# the same modifications as the data received from the client. Without
# this, the comparison afterwards might fail without the data being
# significantly different.
# TODO: we just deserialized from disk, investigate how to make sure that
# the job info and log entries are compatible to avoid this further step.
# TODO: Doing something like in testutils.py:UnifyValueType might be more
# efficient, though floats will be tricky
job_info = serializer.LoadJson(serializer.DumpJson(job_info))
log_entries = serializer.LoadJson(serializer.DumpJson(log_entries))
# Don't even try to wait if the job is no longer running, there will be
# no changes.
if (status not in (constants.JOB_STATUS_QUEUED,
constants.JOB_STATUS_RUNNING,
constants.JOB_STATUS_WAITING) or
job_info != self._prev_job_info or
(log_entries and self._prev_log_serial != log_entries[0][0])):
logging.debug("Job %s changed", job.id)
return (job_info, log_entries)
return None
class _JobFileChangesWaiter(object):
def __init__(self, filename):
"""Initializes this class.
@type filename: string
@param filename: Path to job file
@raises errors.InotifyError: if the notifier cannot be setup
"""
self._wm = pyinotify.WatchManager()
self._inotify_handler = \
asyncnotifier.SingleFileEventHandler(self._wm, self._OnInotify, filename)
self._notifier = \
pyinotify.Notifier(self._wm, default_proc_fun=self._inotify_handler)
try:
self._inotify_handler.enable()
except Exception:
# pyinotify doesn't close file descriptors automatically
self._notifier.stop()
raise
def _OnInotify(self, notifier_enabled):
"""Callback for inotify.
"""
if not notifier_enabled:
self._inotify_handler.enable()
def Wait(self, timeout):
"""Waits for the job file to change.
@type timeout: float
@param timeout: Timeout in seconds
@return: Whether there have been events
"""
assert timeout >= 0
have_events = self._notifier.check_events(timeout * 1000)
if have_events:
self._notifier.read_events()
self._notifier.process_events()
return have_events
def Close(self):
"""Closes underlying notifier and its file descriptor.
"""
self._notifier.stop()
class _JobChangesWaiter(object):
def __init__(self, filename):
"""Initializes this class.
@type filename: string
@param filename: Path to job file
"""
self._filewaiter = None
self._filename = filename
def Wait(self, timeout):
"""Waits for a job to change.
@type timeout: float
@param timeout: Timeout in seconds
@return: Whether there have been events
"""
if self._filewaiter:
return self._filewaiter.Wait(timeout)
# Lazy setup: Avoid inotify setup cost when job file has already changed.
# If this point is reached, return immediately and let caller check the job
# file again in case there were changes since the last check. This avoids a
# race condition.
self._filewaiter = _JobFileChangesWaiter(self._filename)
return True
def Close(self):
"""Closes underlying waiter.
"""
if self._filewaiter:
self._filewaiter.Close()
class _WaitForJobChangesHelper(object):
"""Helper class using inotify to wait for changes in a job file.
This class takes a previous job status and serial, and alerts the client when
the current job status has changed.
"""
@staticmethod
def _CheckForChanges(counter, job_load_fn, check_fn):
if counter.next() > 0:
# If this isn't the first check the job is given some more time to change
# again. This gives better performance for jobs generating many
# changes/messages.
time.sleep(0.1)
job = job_load_fn()
if not job:
raise errors.JobLost()
result = check_fn(job)
if result is None:
raise utils.RetryAgain()
return result
def __call__(self, filename, job_load_fn,
fields, prev_job_info, prev_log_serial, timeout):
"""Waits for changes on a job.
@type filename: string
@param filename: File on which to wait for changes
@type job_load_fn: callable
@param job_load_fn: Function to load job
@type fields: list of strings
@param fields: Which fields to check for changes
@type prev_job_info: list or None
@param prev_job_info: Last job information returned
@type prev_log_serial: int
@param prev_log_serial: Last job message serial number
@type timeout: float
@param timeout: maximum time to wait in seconds
"""
counter = itertools.count()
try:
check_fn = _JobChangesChecker(fields, prev_job_info, prev_log_serial)
waiter = _JobChangesWaiter(filename)
try:
return utils.Retry(compat.partial(self._CheckForChanges,
counter, job_load_fn, check_fn),
utils.RETRY_REMAINING_TIME, timeout,
wait_fn=waiter.Wait)
finally:
waiter.Close()
except (errors.InotifyError, errors.JobLost):
return None
except utils.RetryTimeout:
return constants.JOB_NOTCHANGED
def _EncodeOpError(err):
"""Encodes an error which occurred while processing an opcode.
"""
if isinstance(err, errors.GenericError):
to_encode = err
else:
to_encode = errors.OpExecError(str(err))
return errors.EncodeException(to_encode)
class _TimeoutStrategyWrapper:
def __init__(self, fn):
"""Initializes this class.
"""
self._fn = fn
self._next = None
def _Advance(self):
"""Gets the next timeout if necessary.
"""
if self._next is None:
self._next = self._fn()
def Peek(self):
"""Returns the next timeout.
"""
self._Advance()
return self._next
def Next(self):
"""Returns the current timeout and advances the internal state.
"""
self._Advance()
result = self._next
self._next = None
return result
class _OpExecContext:
def __init__(self, op, index, log_prefix, timeout_strategy_factory):
"""Initializes this class.
"""
self.op = op
self.index = index
self.log_prefix = log_prefix
self.summary = op.input.Summary()
# Create local copy to modify
if getattr(op.input, opcodes.DEPEND_ATTR, None):
self.jobdeps = op.input.depends[:]
else:
self.jobdeps = None
self._timeout_strategy_factory = timeout_strategy_factory
self._ResetTimeoutStrategy()
def _ResetTimeoutStrategy(self):
"""Creates a new timeout strategy.
"""
self._timeout_strategy = \
_TimeoutStrategyWrapper(self._timeout_strategy_factory().NextAttempt)
def CheckPriorityIncrease(self):
"""Checks whether priority can and should be increased.
Called when locks couldn't be acquired.
"""
op = self.op
# Exhausted all retries and next round should not use blocking acquire
# for locks?
if (self._timeout_strategy.Peek() is None and
op.priority > constants.OP_PRIO_HIGHEST):
logging.debug("Increasing priority")
op.priority -= 1
self._ResetTimeoutStrategy()
return True
return False
def GetNextLockTimeout(self):
"""Returns the next lock acquire timeout.
"""
return self._timeout_strategy.Next()
class _JobProcessor(object):
(DEFER,
WAITDEP,
FINISHED) = range(1, 4)
def __init__(self, queue, opexec_fn, job,
_timeout_strategy_factory=mcpu.LockAttemptTimeoutStrategy):
"""Initializes this class.
"""
self.queue = queue
self.opexec_fn = opexec_fn
self.job = job
self._timeout_strategy_factory = _timeout_strategy_factory
@staticmethod
def _FindNextOpcode(job, timeout_strategy_factory):
"""Locates the next opcode to run.
@type job: L{_QueuedJob}
@param job: Job object
@param timeout_strategy_factory: Callable to create new timeout strategy
"""
# Create some sort of a cache to speed up locating next opcode for future
# lookups
# TODO: Consider splitting _QueuedJob.ops into two separate lists, one for
# pending and one for processed ops.
if job.ops_iter is None:
job.ops_iter = enumerate(job.ops)
# Find next opcode to run
while True:
try:
(idx, op) = job.ops_iter.next()
except StopIteration:
raise errors.ProgrammerError("Called for a finished job")
if op.status == constants.OP_STATUS_RUNNING:
# Found an opcode already marked as running
raise errors.ProgrammerError("Called for job marked as running")
opctx = _OpExecContext(op, idx, "Op %s/%s" % (idx + 1, len(job.ops)),
timeout_strategy_factory)
if op.status not in constants.OPS_FINALIZED:
return opctx
# This is a job that was partially completed before master daemon
# shutdown, so it can be expected that some opcodes are already
# completed successfully (if any did error out, then the whole job
# should have been aborted and not resubmitted for processing).
logging.info("%s: opcode %s already processed, skipping",
opctx.log_prefix, opctx.summary)
@staticmethod
def _MarkWaitlock(job, op):
"""Marks an opcode as waiting for locks.
The job's start timestamp is also set if necessary.
@type job: L{_QueuedJob}
@param job: Job object
@type op: L{_QueuedOpCode}
@param op: Opcode object
"""
assert op in job.ops
assert op.status in (constants.OP_STATUS_QUEUED,
constants.OP_STATUS_WAITING)
update = False
op.result = None
if op.status == constants.OP_STATUS_QUEUED:
op.status = constants.OP_STATUS_WAITING
update = True
if op.start_timestamp is None:
op.start_timestamp = TimeStampNow()
update = True
if job.start_timestamp is None:
job.start_timestamp = op.start_timestamp
update = True
assert op.status == constants.OP_STATUS_WAITING
return update
@staticmethod
def _CheckDependencies(queue, job, opctx):
"""Checks if an opcode has dependencies and if so, processes them.
@type queue: L{JobQueue}
@param queue: Queue object
@type job: L{_QueuedJob}
@param job: Job object
@type opctx: L{_OpExecContext}
@param opctx: Opcode execution context
@rtype: bool
@return: Whether opcode will be re-scheduled by dependency tracker
"""
op = opctx.op
result = False
while opctx.jobdeps:
(dep_job_id, dep_status) = opctx.jobdeps[0]
(depresult, depmsg) = queue.depmgr.CheckAndRegister(job, dep_job_id,
dep_status)
assert ht.TNonEmptyString(depmsg), "No dependency message"
logging.info("%s: %s", opctx.log_prefix, depmsg)
if depresult == _JobDependencyManager.CONTINUE:
# Remove dependency and continue
opctx.jobdeps.pop(0)
elif depresult == _JobDependencyManager.WAIT:
# Need to wait for notification, dependency tracker will re-add job
# to workerpool
result = True
break
elif depresult == _JobDependencyManager.CANCEL:
# Job was cancelled, cancel this job as well
job.Cancel()
assert op.status == constants.OP_STATUS_CANCELING
break
elif depresult in (_JobDependencyManager.WRONGSTATUS,
_JobDependencyManager.ERROR):
# Job failed or there was an error, this job must fail
op.status = constants.OP_STATUS_ERROR
op.result = _EncodeOpError(errors.OpExecError(depmsg))
break
else:
raise errors.ProgrammerError("Unknown dependency result '%s'" %
depresult)
return result
def _ExecOpCodeUnlocked(self, opctx):
"""Processes one opcode and returns the result.
"""
op = opctx.op
assert op.status == constants.OP_STATUS_WAITING
timeout = opctx.GetNextLockTimeout()
try:
# Make sure not to hold queue lock while calling ExecOpCode
result = self.opexec_fn(op.input,
_OpExecCallbacks(self.queue, self.job, op),
timeout=timeout, priority=op.priority)
except mcpu.LockAcquireTimeout:
assert timeout is not None, "Received timeout for blocking acquire"
logging.debug("Couldn't acquire locks in %0.6fs", timeout)
assert op.status in (constants.OP_STATUS_WAITING,
constants.OP_STATUS_CANCELING)
# Was job cancelled while we were waiting for the lock?
if op.status == constants.OP_STATUS_CANCELING:
return (constants.OP_STATUS_CANCELING, None)
# Stay in waitlock while trying to re-acquire lock
return (constants.OP_STATUS_WAITING, None)
except CancelJob:
logging.exception("%s: Canceling job", opctx.log_prefix)
assert op.status == constants.OP_STATUS_CANCELING
return (constants.OP_STATUS_CANCELING, None)
except Exception, err: # pylint: disable=W0703
logging.exception("%s: Caught exception in %s",
opctx.log_prefix, opctx.summary)
return (constants.OP_STATUS_ERROR, _EncodeOpError(err))
else:
logging.debug("%s: %s successful",
opctx.log_prefix, opctx.summary)
return (constants.OP_STATUS_SUCCESS, result)
def __call__(self, _nextop_fn=None):
"""Continues execution of a job.
@param _nextop_fn: Callback function for tests
@return: C{FINISHED} if job is fully processed, C{DEFER} if the job should
be deferred and C{WAITDEP} if the dependency manager
(L{_JobDependencyManager}) will re-schedule the job when appropriate
"""
queue = self.queue
job = self.job
logging.debug("Processing job %s", job.id)
queue.acquire(shared=1)
try:
opcount = len(job.ops)
assert job.writable, "Expected writable job"
# Don't do anything for finalized jobs
if job.CalcStatus() in constants.JOBS_FINALIZED:
return self.FINISHED
# Is a previous opcode still pending?
if job.cur_opctx:
opctx = job.cur_opctx
job.cur_opctx = None
else:
if __debug__ and _nextop_fn:
_nextop_fn()
opctx = self._FindNextOpcode(job, self._timeout_strategy_factory)
op = opctx.op
# Consistency check
assert compat.all(i.status in (constants.OP_STATUS_QUEUED,
constants.OP_STATUS_CANCELING)
for i in job.ops[opctx.index + 1:])
assert op.status in (constants.OP_STATUS_QUEUED,
constants.OP_STATUS_WAITING,
constants.OP_STATUS_CANCELING)
assert (op.priority <= constants.OP_PRIO_LOWEST and
op.priority >= constants.OP_PRIO_HIGHEST)
waitjob = None
if op.status != constants.OP_STATUS_CANCELING:
assert op.status in (constants.OP_STATUS_QUEUED,
constants.OP_STATUS_WAITING)
# Prepare to start opcode
if self._MarkWaitlock(job, op):
# Write to disk
queue.UpdateJobUnlocked(job)
assert op.status == constants.OP_STATUS_WAITING
assert job.CalcStatus() == constants.JOB_STATUS_WAITING
assert job.start_timestamp and op.start_timestamp
assert waitjob is None
# Check if waiting for a job is necessary
waitjob = self._CheckDependencies(queue, job, opctx)
assert op.status in (constants.OP_STATUS_WAITING,
constants.OP_STATUS_CANCELING,
constants.OP_STATUS_ERROR)
if not (waitjob or op.status in (constants.OP_STATUS_CANCELING,
constants.OP_STATUS_ERROR)):
logging.info("%s: opcode %s waiting for locks",
opctx.log_prefix, opctx.summary)
assert not opctx.jobdeps, "Not all dependencies were removed"
queue.release()
try:
(op_status, op_result) = self._ExecOpCodeUnlocked(opctx)
finally:
queue.acquire(shared=1)
op.status = op_status
op.result = op_result
assert not waitjob
if op.status == constants.OP_STATUS_WAITING:
# Couldn't get locks in time
assert not op.end_timestamp
else:
# Finalize opcode
op.end_timestamp = TimeStampNow()
if op.status == constants.OP_STATUS_CANCELING:
assert not compat.any(i.status != constants.OP_STATUS_CANCELING
for i in job.ops[opctx.index:])
else:
assert op.status in constants.OPS_FINALIZED
if op.status == constants.OP_STATUS_WAITING or waitjob:
finalize = False
if not waitjob and opctx.CheckPriorityIncrease():
# Priority was changed, need to update on-disk file
queue.UpdateJobUnlocked(job)
# Keep around for another round
job.cur_opctx = opctx
assert (op.priority <= constants.OP_PRIO_LOWEST and
op.priority >= constants.OP_PRIO_HIGHEST)
# In no case must the status be finalized here
assert job.CalcStatus() == constants.JOB_STATUS_WAITING
else:
# Ensure all opcodes so far have been successful
assert (opctx.index == 0 or
compat.all(i.status == constants.OP_STATUS_SUCCESS
for i in job.ops[:opctx.index]))
# Reset context
job.cur_opctx = None
if op.status == constants.OP_STATUS_SUCCESS:
finalize = False
elif op.status == constants.OP_STATUS_ERROR:
# Ensure failed opcode has an exception as its result
assert errors.GetEncodedError(job.ops[opctx.index].result)
to_encode = errors.OpExecError("Preceding opcode failed")
job.MarkUnfinishedOps(constants.OP_STATUS_ERROR,
_EncodeOpError(to_encode))
finalize = True
# Consistency check
assert compat.all(i.status == constants.OP_STATUS_ERROR and
errors.GetEncodedError(i.result)
for i in job.ops[opctx.index:])
elif op.status == constants.OP_STATUS_CANCELING:
job.MarkUnfinishedOps(constants.OP_STATUS_CANCELED,
"Job canceled by request")
finalize = True
else:
raise errors.ProgrammerError("Unknown status '%s'" % op.status)
if opctx.index == (opcount - 1):
# Finalize on last opcode
finalize = True
if finalize:
# All opcodes have been run, finalize job
job.Finalize()
# Write to disk. If the job status is final, this is the final write
# allowed. Once the file has been written, it can be archived anytime.
queue.UpdateJobUnlocked(job)
assert not waitjob
if finalize:
logging.info("Finished job %s, status = %s", job.id, job.CalcStatus())
return self.FINISHED
assert not waitjob or queue.depmgr.JobWaiting(job)
if waitjob:
return self.WAITDEP
else:
return self.DEFER
finally:
assert job.writable, "Job became read-only while being processed"
queue.release()
def _EvaluateJobProcessorResult(depmgr, job, result):
"""Looks at a result from L{_JobProcessor} for a job.
To be used in a L{_JobQueueWorker}.
"""
if result == _JobProcessor.FINISHED:
# Notify waiting jobs
depmgr.NotifyWaiters(job.id)
elif result == _JobProcessor.DEFER:
# Schedule again
raise workerpool.DeferTask(priority=job.CalcPriority())
elif result == _JobProcessor.WAITDEP:
# No-op, dependency manager will re-schedule
pass
else:
raise errors.ProgrammerError("Job processor returned unknown status %s" %
(result, ))
class _JobQueueWorker(workerpool.BaseWorker):
"""The actual job workers.
"""
def RunTask(self, job): # pylint: disable=W0221
"""Job executor.
@type job: L{_QueuedJob}
@param job: the job to be processed
"""
assert job.writable, "Expected writable job"
# Ensure only one worker is active on a single job. If a job registers for
# a dependency job, and the other job notifies before the first worker is
# done, the job can end up in the tasklist more than once.
job.processor_lock.acquire()
try:
return self._RunTaskInner(job)
finally:
job.processor_lock.release()
def _RunTaskInner(self, job):
"""Executes a job.
Must be called with per-job lock acquired.
"""
queue = job.queue
assert queue == self.pool.queue
setname_fn = lambda op: self.SetTaskName(self._GetWorkerName(job, op))
setname_fn(None)
proc = mcpu.Processor(queue.context, job.id)
# Create wrapper for setting thread name
wrap_execop_fn = compat.partial(self._WrapExecOpCode, setname_fn,
proc.ExecOpCode)
_EvaluateJobProcessorResult(queue.depmgr, job,
_JobProcessor(queue, wrap_execop_fn, job)())
@staticmethod
def _WrapExecOpCode(setname_fn, execop_fn, op, *args, **kwargs):
"""Updates the worker thread name to include a short summary of the opcode.
@param setname_fn: Callable setting worker thread name
@param execop_fn: Callable for executing opcode (usually
L{mcpu.Processor.ExecOpCode})
"""
setname_fn(op)
try:
return execop_fn(op, *args, **kwargs)
finally:
setname_fn(None)
@staticmethod
def _GetWorkerName(job, op):
"""Sets the worker thread name.
@type job: L{_QueuedJob}
@type op: L{opcodes.OpCode}
"""
parts = ["Job%s" % job.id]
if op:
parts.append(op.TinySummary())
return "/".join(parts)
class _JobQueueWorkerPool(workerpool.WorkerPool):
"""Simple class implementing a job-processing workerpool.
"""
def __init__(self, queue):
super(_JobQueueWorkerPool, self).__init__("Jq",
JOBQUEUE_THREADS,
_JobQueueWorker)
self.queue = queue
class _JobDependencyManager:
"""Keeps track of job dependencies.
"""
(WAIT,
ERROR,
CANCEL,
CONTINUE,
WRONGSTATUS) = range(1, 6)
def __init__(self, getstatus_fn, enqueue_fn):
"""Initializes this class.
"""
self._getstatus_fn = getstatus_fn
self._enqueue_fn = enqueue_fn
self._waiters = {}
self._lock = locking.SharedLock("JobDepMgr")
@locking.ssynchronized(_LOCK, shared=1)
def GetLockInfo(self, requested): # pylint: disable=W0613
"""Retrieves information about waiting jobs.
@type requested: set
@param requested: Requested information, see C{query.LQ_*}
"""
# No need to sort here, that's being done by the lock manager and query
# library. There are no priorities for notifying jobs, hence all show up as
# one item under "pending".
return [("job/%s" % job_id, None, None,
[("job", [job.id for job in waiters])])
for job_id, waiters in self._waiters.items()
if waiters]
@locking.ssynchronized(_LOCK, shared=1)
def JobWaiting(self, job):
"""Checks if a job is waiting.
"""
return compat.any(job in jobs
for jobs in self._waiters.values())
@locking.ssynchronized(_LOCK)
def CheckAndRegister(self, job, dep_job_id, dep_status):
"""Checks if a dependency job has the requested status.
If the other job is not yet in a finalized status, the calling job will be
notified (re-added to the workerpool) at a later point.
@type job: L{_QueuedJob}
@param job: Job object
@type dep_job_id: string
@param dep_job_id: ID of dependency job
@type dep_status: list
@param dep_status: Required status
"""
assert ht.TString(job.id)
assert ht.TString(dep_job_id)
assert ht.TListOf(ht.TElemOf(constants.JOBS_FINALIZED))(dep_status)
if job.id == dep_job_id:
return (self.ERROR, "Job can't depend on itself")
# Get status of dependency job
try:
status = self._getstatus_fn(dep_job_id)
except errors.JobLost, err:
return (self.ERROR, "Dependency error: %s" % err)
assert status in constants.JOB_STATUS_ALL
job_id_waiters = self._waiters.setdefault(dep_job_id, set())
if status not in constants.JOBS_FINALIZED:
# Register for notification and wait for job to finish
job_id_waiters.add(job)
return (self.WAIT,
"Need to wait for job %s, wanted status '%s'" %
(dep_job_id, dep_status))
# Remove from waiters list
if job in job_id_waiters:
job_id_waiters.remove(job)
if (status == constants.JOB_STATUS_CANCELED and
constants.JOB_STATUS_CANCELED not in dep_status):
return (self.CANCEL, "Dependency job %s was cancelled" % dep_job_id)
elif not dep_status or status in dep_status:
return (self.CONTINUE,
"Dependency job %s finished with status '%s'" %
(dep_job_id, status))
else:
return (self.WRONGSTATUS,
"Dependency job %s finished with status '%s',"
" not one of '%s' as required" %
(dep_job_id, status, utils.CommaJoin(dep_status)))
def _RemoveEmptyWaitersUnlocked(self):
"""Remove all jobs without actual waiters.
"""
for job_id in [job_id for (job_id, waiters) in self._waiters.items()
if not waiters]:
del self._waiters[job_id]
def NotifyWaiters(self, job_id):
"""Notifies all jobs waiting for a certain job ID.
@attention: Do not call until L{CheckAndRegister} returned a status other
than C{WAITDEP} for C{job_id}, or behaviour is undefined
@type job_id: string
@param job_id: Job ID
"""
assert ht.TString(job_id)
self._lock.acquire()
try:
self._RemoveEmptyWaitersUnlocked()
jobs = self._waiters.pop(job_id, None)
finally:
self._lock.release()
if jobs:
# Re-add jobs to workerpool
logging.debug("Re-adding %s jobs which were waiting for job %s",
len(jobs), job_id)
self._enqueue_fn(jobs)
def _RequireOpenQueue(fn):
"""Decorator for "public" functions.
This function should be used for all 'public' functions. That is,
functions usually called from other classes. Note that this should
be applied only to methods (not plain functions), since it expects
that the decorated function is called with a first argument that has
a '_queue_filelock' argument.
@warning: Use this decorator only after locking.ssynchronized
Example::
@locking.ssynchronized(_LOCK)
@_RequireOpenQueue
def Example(self):
pass
"""
def wrapper(self, *args, **kwargs):
# pylint: disable=W0212
assert self._queue_filelock is not None, "Queue should be open"
return fn(self, *args, **kwargs)
return wrapper
def _RequireNonDrainedQueue(fn):
"""Decorator checking for a non-drained queue.
To be used with functions submitting new jobs.
"""
def wrapper(self, *args, **kwargs):
"""Wrapper function.
@raise errors.JobQueueDrainError: if the job queue is marked for draining
"""
# Ok when sharing the big job queue lock, as the drain file is created when
# the lock is exclusive.
# Needs access to protected member, pylint: disable=W0212
if self._drained:
raise errors.JobQueueDrainError("Job queue is drained, refusing job")
if not self._accepting_jobs:
raise errors.JobQueueError("Job queue is shutting down, refusing job")
return fn(self, *args, **kwargs)
return wrapper
class JobQueue(object):
"""Queue used to manage the jobs.
"""
def __init__(self, context):
"""Constructor for JobQueue.
The constructor will initialize the job queue object and then
start loading the current jobs from disk, either for starting them
(if they were queue) or for aborting them (if they were already
running).
@type context: GanetiContext
@param context: the context object for access to the configuration
data and other ganeti objects
"""
self.context = context
self._memcache = weakref.WeakValueDictionary()
self._my_hostname = netutils.Hostname.GetSysName()
# The Big JobQueue lock. If a code block or method acquires it in shared
# mode safe it must guarantee concurrency with all the code acquiring it in
# shared mode, including itself. In order not to acquire it at all
# concurrency must be guaranteed with all code acquiring it in shared mode
# and all code acquiring it exclusively.
self._lock = locking.SharedLock("JobQueue")
self.acquire = self._lock.acquire
self.release = self._lock.release
# Accept jobs by default
self._accepting_jobs = True
# Initialize the queue, and acquire the filelock.
# This ensures no other process is working on the job queue.
self._queue_filelock = jstore.InitAndVerifyQueue(must_lock=True)
# Read serial file
self._last_serial = jstore.ReadSerial()
assert self._last_serial is not None, ("Serial file was modified between"
" check in jstore and here")
# Get initial list of nodes
self._nodes = dict((n.name, n.primary_ip)
for n in self.context.cfg.GetAllNodesInfo().values()
if n.master_candidate)
# Remove master node
self._nodes.pop(self._my_hostname, None)
# TODO: Check consistency across nodes
self._queue_size = None
self._UpdateQueueSizeUnlocked()
assert ht.TInt(self._queue_size)
self._drained = jstore.CheckDrainFlag()
# Job dependencies
self.depmgr = _JobDependencyManager(self._GetJobStatusForDependencies,
self._EnqueueJobs)
self.context.glm.AddToLockMonitor(self.depmgr)
# Setup worker pool
self._wpool = _JobQueueWorkerPool(self)
try:
self._InspectQueue()
except:
self._wpool.TerminateWorkers()
raise
@locking.ssynchronized(_LOCK)
@_RequireOpenQueue
def _InspectQueue(self):
"""Loads the whole job queue and resumes unfinished jobs.
This function needs the lock here because WorkerPool.AddTask() may start a
job while we're still doing our work.
"""
logging.info("Inspecting job queue")
restartjobs = []
all_job_ids = self._GetJobIDsUnlocked()
jobs_count = len(all_job_ids)
lastinfo = time.time()
for idx, job_id in enumerate(all_job_ids):
# Give an update every 1000 jobs or 10 seconds
if (idx % 1000 == 0 or time.time() >= (lastinfo + 10.0) or
idx == (jobs_count - 1)):
logging.info("Job queue inspection: %d/%d (%0.1f %%)",
idx, jobs_count - 1, 100.0 * (idx + 1) / jobs_count)
lastinfo = time.time()
job = self._LoadJobUnlocked(job_id)
# a failure in loading the job can cause 'None' to be returned
if job is None:
continue
status = job.CalcStatus()
if status == constants.JOB_STATUS_QUEUED:
restartjobs.append(job)
elif status in (constants.JOB_STATUS_RUNNING,
constants.JOB_STATUS_WAITING,
constants.JOB_STATUS_CANCELING):
logging.warning("Unfinished job %s found: %s", job.id, job)
if status == constants.JOB_STATUS_WAITING:
# Restart job
job.MarkUnfinishedOps(constants.OP_STATUS_QUEUED, None)
restartjobs.append(job)
else:
job.MarkUnfinishedOps(constants.OP_STATUS_ERROR,
"Unclean master daemon shutdown")
job.Finalize()
self.UpdateJobUnlocked(job)
if restartjobs:
logging.info("Restarting %s jobs", len(restartjobs))
self._EnqueueJobsUnlocked(restartjobs)
logging.info("Job queue inspection finished")
def _GetRpc(self, address_list):
"""Gets RPC runner with context.
"""
return rpc.JobQueueRunner(self.context, address_list)
@locking.ssynchronized(_LOCK)
@_RequireOpenQueue
def AddNode(self, node):
"""Register a new node with the queue.
@type node: L{objects.Node}
@param node: the node object to be added
"""
node_name = node.name
assert node_name != self._my_hostname
# Clean queue directory on added node
result = self._GetRpc(None).call_jobqueue_purge(node_name)
msg = result.fail_msg
if msg:
logging.warning("Cannot cleanup queue directory on node %s: %s",
node_name, msg)
if not node.master_candidate:
# remove if existing, ignoring errors
self._nodes.pop(node_name, None)
# and skip the replication of the job ids
return
# Upload the whole queue excluding archived jobs
files = [self._GetJobPath(job_id) for job_id in self._GetJobIDsUnlocked()]
# Upload current serial file
files.append(constants.JOB_QUEUE_SERIAL_FILE)
# Static address list
addrs = [node.primary_ip]
for file_name in files:
# Read file content
content = utils.ReadFile(file_name)
result = self._GetRpc(addrs).call_jobqueue_update([node_name], file_name,
content)
msg = result[node_name].fail_msg
if msg:
logging.error("Failed to upload file %s to node %s: %s",
file_name, node_name, msg)
self._nodes[node_name] = node.primary_ip
@locking.ssynchronized(_LOCK)
@_RequireOpenQueue
def RemoveNode(self, node_name):
"""Callback called when removing nodes from the cluster.
@type node_name: str
@param node_name: the name of the node to remove
"""
self._nodes.pop(node_name, None)
@staticmethod
def _CheckRpcResult(result, nodes, failmsg):
"""Verifies the status of an RPC call.
Since we aim to keep consistency should this node (the current
master) fail, we will log errors if our rpc fail, and especially
log the case when more than half of the nodes fails.
@param result: the data as returned from the rpc call
@type nodes: list
@param nodes: the list of nodes we made the call to
@type failmsg: str
@param failmsg: the identifier to be used for logging
"""
failed = []
success = []
for node in nodes:
msg = result[node].fail_msg
if msg:
failed.append(node)
logging.error("RPC call %s (%s) failed on node %s: %s",
result[node].call, failmsg, node, msg)
else:
success.append(node)
# +1 for the master node
if (len(success) + 1) < len(failed):
# TODO: Handle failing nodes
logging.error("More than half of the nodes failed")
def _GetNodeIp(self):
"""Helper for returning the node name/ip list.
@rtype: (list, list)
@return: a tuple of two lists, the first one with the node
names and the second one with the node addresses
"""
# TODO: Change to "tuple(map(list, zip(*self._nodes.items())))"?
name_list = self._nodes.keys()
addr_list = [self._nodes[name] for name in name_list]
return name_list, addr_list
def _UpdateJobQueueFile(self, file_name, data, replicate):
"""Writes a file locally and then replicates it to all nodes.
This function will replace the contents of a file on the local
node and then replicate it to all the other nodes we have.
@type file_name: str
@param file_name: the path of the file to be replicated
@type data: str
@param data: the new contents of the file
@type replicate: boolean
@param replicate: whether to spread the changes to the remote nodes
"""
getents = runtime.GetEnts()
utils.WriteFile(file_name, data=data, uid=getents.masterd_uid,
gid=getents.masterd_gid)
if replicate:
names, addrs = self._GetNodeIp()
result = self._GetRpc(addrs).call_jobqueue_update(names, file_name, data)
self._CheckRpcResult(result, self._nodes, "Updating %s" % file_name)
def _RenameFilesUnlocked(self, rename):
"""Renames a file locally and then replicate the change.
This function will rename a file in the local queue directory
and then replicate this rename to all the other nodes we have.
@type rename: list of (old, new)
@param rename: List containing tuples mapping old to new names
"""
# Rename them locally
for old, new in rename:
utils.RenameFile(old, new, mkdir=True)
# ... and on all nodes
names, addrs = self._GetNodeIp()
result = self._GetRpc(addrs).call_jobqueue_rename(names, rename)
self._CheckRpcResult(result, self._nodes, "Renaming files (%r)" % rename)
@staticmethod
def _FormatJobID(job_id):
"""Convert a job ID to string format.
Currently this just does C{str(job_id)} after performing some
checks, but if we want to change the job id format this will
abstract this change.
@type job_id: int or long
@param job_id: the numeric job id
@rtype: str
@return: the formatted job id
"""
if not isinstance(job_id, (int, long)):
raise errors.ProgrammerError("Job ID '%s' not numeric" % job_id)
if job_id < 0:
raise errors.ProgrammerError("Job ID %s is negative" % job_id)
return str(job_id)
@classmethod
def _GetArchiveDirectory(cls, job_id):
"""Returns the archive directory for a job.
@type job_id: str
@param job_id: Job identifier
@rtype: str
@return: Directory name
"""
return str(int(job_id) / JOBS_PER_ARCHIVE_DIRECTORY)
def _NewSerialsUnlocked(self, count):
"""Generates a new job identifier.
Job identifiers are unique during the lifetime of a cluster.
@type count: integer
@param count: how many serials to return
@rtype: str
@return: a string representing the job identifier.
"""
assert ht.TPositiveInt(count)
# New number
serial = self._last_serial + count
# Write to file
self._UpdateJobQueueFile(constants.JOB_QUEUE_SERIAL_FILE,
"%s\n" % serial, True)
result = [self._FormatJobID(v)
for v in range(self._last_serial + 1, serial + 1)]
# Keep it only if we were able to write the file
self._last_serial = serial
assert len(result) == count
return result
@staticmethod
def _GetJobPath(job_id):
"""Returns the job file for a given job id.
@type job_id: str
@param job_id: the job identifier
@rtype: str
@return: the path to the job file
"""
return utils.PathJoin(constants.QUEUE_DIR, "job-%s" % job_id)
@classmethod
def _GetArchivedJobPath(cls, job_id):
"""Returns the archived job file for a give job id.
@type job_id: str
@param job_id: the job identifier
@rtype: str
@return: the path to the archived job file
"""
return utils.PathJoin(constants.JOB_QUEUE_ARCHIVE_DIR,
cls._GetArchiveDirectory(job_id), "job-%s" % job_id)
@staticmethod
def _GetJobIDsUnlocked(sort=True):
"""Return all known job IDs.
The method only looks at disk because it's a requirement that all
jobs are present on disk (so in the _memcache we don't have any
extra IDs).
@type sort: boolean
@param sort: perform sorting on the returned job ids
@rtype: list
@return: the list of job IDs
"""
jlist = []
for filename in utils.ListVisibleFiles(constants.QUEUE_DIR):
m = constants.JOB_FILE_RE.match(filename)
if m:
jlist.append(m.group(1))
if sort:
jlist = utils.NiceSort(jlist)
return jlist
def _LoadJobUnlocked(self, job_id):
"""Loads a job from the disk or memory.
Given a job id, this will return the cached job object if
existing, or try to load the job from the disk. If loading from
disk, it will also add the job to the cache.
@param job_id: the job id
@rtype: L{_QueuedJob} or None
@return: either None or the job object
"""
job = self._memcache.get(job_id, None)
if job:
logging.debug("Found job %s in memcache", job_id)
assert job.writable, "Found read-only job in memcache"
return job
try:
job = self._LoadJobFromDisk(job_id, False)
if job is None:
return job
except errors.JobFileCorrupted:
old_path = self._GetJobPath(job_id)
new_path = self._GetArchivedJobPath(job_id)
if old_path == new_path:
# job already archived (future case)
logging.exception("Can't parse job %s", job_id)
else:
# non-archived case
logging.exception("Can't parse job %s, will archive.", job_id)
self._RenameFilesUnlocked([(old_path, new_path)])
return None
assert job.writable, "Job just loaded is not writable"
self._memcache[job_id] = job
logging.debug("Added job %s to the cache", job_id)
return job
def _LoadJobFromDisk(self, job_id, try_archived, writable=None):
"""Load the given job file from disk.
Given a job file, read, load and restore it in a _QueuedJob format.
@type job_id: string
@param job_id: job identifier
@type try_archived: bool
@param try_archived: Whether to try loading an archived job
@rtype: L{_QueuedJob} or None
@return: either None or the job object
"""
path_functions = [(self._GetJobPath, True)]
if try_archived:
path_functions.append((self._GetArchivedJobPath, False))
raw_data = None
writable_default = None
for (fn, writable_default) in path_functions:
filepath = fn(job_id)
logging.debug("Loading job from %s", filepath)
try:
raw_data = utils.ReadFile(filepath)
except EnvironmentError, err:
if err.errno != errno.ENOENT:
raise
else:
break
if not raw_data:
return None
if writable is None:
writable = writable_default
try:
data = serializer.LoadJson(raw_data)
job = _QueuedJob.Restore(self, data, writable)
except Exception, err: # pylint: disable=W0703
raise errors.JobFileCorrupted(err)
return job
def SafeLoadJobFromDisk(self, job_id, try_archived, writable=None):
"""Load the given job file from disk.
Given a job file, read, load and restore it in a _QueuedJob format.
In case of error reading the job, it gets returned as None, and the
exception is logged.
@type job_id: string
@param job_id: job identifier
@type try_archived: bool
@param try_archived: Whether to try loading an archived job
@rtype: L{_QueuedJob} or None
@return: either None or the job object
"""
try:
return self._LoadJobFromDisk(job_id, try_archived, writable=writable)
except (errors.JobFileCorrupted, EnvironmentError):
logging.exception("Can't load/parse job %s", job_id)
return None
def _UpdateQueueSizeUnlocked(self):
"""Update the queue size.
"""
self._queue_size = len(self._GetJobIDsUnlocked(sort=False))
@locking.ssynchronized(_LOCK)
@_RequireOpenQueue
def SetDrainFlag(self, drain_flag):
"""Sets the drain flag for the queue.
@type drain_flag: boolean
@param drain_flag: Whether to set or unset the drain flag
"""
jstore.SetDrainFlag(drain_flag)
self._drained = drain_flag
return True
@_RequireOpenQueue
def _SubmitJobUnlocked(self, job_id, ops):
"""Create and store a new job.
This enters the job into our job queue and also puts it on the new
queue, in order for it to be picked up by the queue processors.
@type job_id: job ID
@param job_id: the job ID for the new job
@type ops: list
@param ops: The list of OpCodes that will become the new job.
@rtype: L{_QueuedJob}
@return: the job object to be queued
@raise errors.JobQueueFull: if the job queue has too many jobs in it
@raise errors.GenericError: If an opcode is not valid
"""
if self._queue_size >= constants.JOB_QUEUE_SIZE_HARD_LIMIT:
raise errors.JobQueueFull()
job = _QueuedJob(self, job_id, ops, True)
# Check priority
for idx, op in enumerate(job.ops):
if op.priority not in constants.OP_PRIO_SUBMIT_VALID:
allowed = utils.CommaJoin(constants.OP_PRIO_SUBMIT_VALID)
raise errors.GenericError("Opcode %s has invalid priority %s, allowed"
" are %s" % (idx, op.priority, allowed))
dependencies = getattr(op.input, opcodes.DEPEND_ATTR, None)
if not opcodes.TNoRelativeJobDependencies(dependencies):
raise errors.GenericError("Opcode %s has invalid dependencies, must"
" match %s: %s" %
(idx, opcodes.TNoRelativeJobDependencies,
dependencies))
# Write to disk
self.UpdateJobUnlocked(job)
self._queue_size += 1
logging.debug("Adding new job %s to the cache", job_id)
self._memcache[job_id] = job
return job
@locking.ssynchronized(_LOCK)
@_RequireOpenQueue
@_RequireNonDrainedQueue
def SubmitJob(self, ops):
"""Create and store a new job.
@see: L{_SubmitJobUnlocked}
"""
(job_id, ) = self._NewSerialsUnlocked(1)
self._EnqueueJobsUnlocked([self._SubmitJobUnlocked(job_id, ops)])
return job_id
@locking.ssynchronized(_LOCK)
@_RequireOpenQueue
@_RequireNonDrainedQueue
def SubmitManyJobs(self, jobs):
"""Create and store multiple jobs.
@see: L{_SubmitJobUnlocked}
"""
all_job_ids = self._NewSerialsUnlocked(len(jobs))
(results, added_jobs) = \
self._SubmitManyJobsUnlocked(jobs, all_job_ids, [])
self._EnqueueJobsUnlocked(added_jobs)
return results
@staticmethod
def _FormatSubmitError(msg, ops):
"""Formats errors which occurred while submitting a job.
"""
return ("%s; opcodes %s" %
(msg, utils.CommaJoin(op.Summary() for op in ops)))
@staticmethod
def _ResolveJobDependencies(resolve_fn, deps):
"""Resolves relative job IDs in dependencies.
@type resolve_fn: callable
@param resolve_fn: Function to resolve a relative job ID
@type deps: list
@param deps: Dependencies
@rtype: list
@return: Resolved dependencies
"""
result = []
for (dep_job_id, dep_status) in deps:
if ht.TRelativeJobId(dep_job_id):
assert ht.TInt(dep_job_id) and dep_job_id < 0
try:
job_id = resolve_fn(dep_job_id)
except IndexError:
# Abort
return (False, "Unable to resolve relative job ID %s" % dep_job_id)
else:
job_id = dep_job_id
result.append((job_id, dep_status))
return (True, result)
def _SubmitManyJobsUnlocked(self, jobs, job_ids, previous_job_ids):
"""Create and store multiple jobs.
@see: L{_SubmitJobUnlocked}
"""
results = []
added_jobs = []
def resolve_fn(job_idx, reljobid):
assert reljobid < 0
return (previous_job_ids + job_ids[:job_idx])[reljobid]
for (idx, (job_id, ops)) in enumerate(zip(job_ids, jobs)):
for op in ops:
if getattr(op, opcodes.DEPEND_ATTR, None):
(status, data) = \
self._ResolveJobDependencies(compat.partial(resolve_fn, idx),
op.depends)
if not status:
# Abort resolving dependencies
assert ht.TNonEmptyString(data), "No error message"
break
# Use resolved dependencies
op.depends = data
else:
try:
job = self._SubmitJobUnlocked(job_id, ops)
except errors.GenericError, err:
status = False
data = self._FormatSubmitError(str(err), ops)
else:
status = True
data = job_id
added_jobs.append(job)
results.append((status, data))
return (results, added_jobs)
@locking.ssynchronized(_LOCK)
def _EnqueueJobs(self, jobs):
"""Helper function to add jobs to worker pool's queue.
@type jobs: list
@param jobs: List of all jobs
"""
return self._EnqueueJobsUnlocked(jobs)
def _EnqueueJobsUnlocked(self, jobs):
"""Helper function to add jobs to worker pool's queue.
@type jobs: list
@param jobs: List of all jobs
"""
assert self._lock.is_owned(shared=0), "Must own lock in exclusive mode"
self._wpool.AddManyTasks([(job, ) for job in jobs],
priority=[job.CalcPriority() for job in jobs])
def _GetJobStatusForDependencies(self, job_id):
"""Gets the status of a job for dependencies.
@type job_id: string
@param job_id: Job ID
@raise errors.JobLost: If job can't be found
"""
if not isinstance(job_id, basestring):
job_id = self._FormatJobID(job_id)
# Not using in-memory cache as doing so would require an exclusive lock
# Try to load from disk
job = self.SafeLoadJobFromDisk(job_id, True, writable=False)
assert not job.writable, "Got writable job" # pylint: disable=E1101
if job:
return job.CalcStatus()
raise errors.JobLost("Job %s not found" % job_id)
@_RequireOpenQueue
def UpdateJobUnlocked(self, job, replicate=True):
"""Update a job's on disk storage.
After a job has been modified, this function needs to be called in
order to write the changes to disk and replicate them to the other
nodes.
@type job: L{_QueuedJob}
@param job: the changed job
@type replicate: boolean
@param replicate: whether to replicate the change to remote nodes
"""
if __debug__:
finalized = job.CalcStatus() in constants.JOBS_FINALIZED
assert (finalized ^ (job.end_timestamp is None))
assert job.writable, "Can't update read-only job"
filename = self._GetJobPath(job.id)
data = serializer.DumpJson(job.Serialize())
logging.debug("Writing job %s to %s", job.id, filename)
self._UpdateJobQueueFile(filename, data, replicate)
def WaitForJobChanges(self, job_id, fields, prev_job_info, prev_log_serial,
timeout):
"""Waits for changes in a job.
@type job_id: string
@param job_id: Job identifier
@type fields: list of strings
@param fields: Which fields to check for changes
@type prev_job_info: list or None
@param prev_job_info: Last job information returned
@type prev_log_serial: int
@param prev_log_serial: Last job message serial number
@type timeout: float
@param timeout: maximum time to wait in seconds
@rtype: tuple (job info, log entries)
@return: a tuple of the job information as required via
the fields parameter, and the log entries as a list
if the job has not changed and the timeout has expired,
we instead return a special value,
L{constants.JOB_NOTCHANGED}, which should be interpreted
as such by the clients
"""
load_fn = compat.partial(self.SafeLoadJobFromDisk, job_id, False,
writable=False)
helper = _WaitForJobChangesHelper()
return helper(self._GetJobPath(job_id), load_fn,
fields, prev_job_info, prev_log_serial, timeout)
@locking.ssynchronized(_LOCK)
@_RequireOpenQueue
def CancelJob(self, job_id):
"""Cancels a job.
This will only succeed if the job has not started yet.
@type job_id: string
@param job_id: job ID of job to be cancelled.
"""
logging.info("Cancelling job %s", job_id)
job = self._LoadJobUnlocked(job_id)
if not job:
logging.debug("Job %s not found", job_id)
return (False, "Job %s not found" % job_id)
assert job.writable, "Can't cancel read-only job"
(success, msg) = job.Cancel()
if success:
# If the job was finalized (e.g. cancelled), this is the final write
# allowed. The job can be archived anytime.
self.UpdateJobUnlocked(job)
return (success, msg)
@_RequireOpenQueue
def _ArchiveJobsUnlocked(self, jobs):
"""Archives jobs.
@type jobs: list of L{_QueuedJob}
@param jobs: Job objects
@rtype: int
@return: Number of archived jobs
"""
archive_jobs = []
rename_files = []
for job in jobs:
assert job.writable, "Can't archive read-only job"
if job.CalcStatus() not in constants.JOBS_FINALIZED:
logging.debug("Job %s is not yet done", job.id)
continue
archive_jobs.append(job)
old = self._GetJobPath(job.id)
new = self._GetArchivedJobPath(job.id)
rename_files.append((old, new))
# TODO: What if 1..n files fail to rename?
self._RenameFilesUnlocked(rename_files)
logging.debug("Successfully archived job(s) %s",
utils.CommaJoin(job.id for job in archive_jobs))
# Since we haven't quite checked, above, if we succeeded or failed renaming
# the files, we update the cached queue size from the filesystem. When we
# get around to fix the TODO: above, we can use the number of actually
# archived jobs to fix this.
self._UpdateQueueSizeUnlocked()
return len(archive_jobs)
@locking.ssynchronized(_LOCK)
@_RequireOpenQueue
def ArchiveJob(self, job_id):
"""Archives a job.
This is just a wrapper over L{_ArchiveJobsUnlocked}.
@type job_id: string
@param job_id: Job ID of job to be archived.
@rtype: bool
@return: Whether job was archived
"""
logging.info("Archiving job %s", job_id)
job = self._LoadJobUnlocked(job_id)
if not job:
logging.debug("Job %s not found", job_id)
return False
return self._ArchiveJobsUnlocked([job]) == 1
@locking.ssynchronized(_LOCK)
@_RequireOpenQueue
def AutoArchiveJobs(self, age, timeout):
"""Archives all jobs based on age.
The method will archive all jobs which are older than the age
parameter. For jobs that don't have an end timestamp, the start
timestamp will be considered. The special '-1' age will cause
archival of all jobs (that are not running or queued).
@type age: int
@param age: the minimum age in seconds
"""
logging.info("Archiving jobs with age more than %s seconds", age)
now = time.time()
end_time = now + timeout
archived_count = 0
last_touched = 0
all_job_ids = self._GetJobIDsUnlocked()
pending = []
for idx, job_id in enumerate(all_job_ids):
last_touched = idx + 1
# Not optimal because jobs could be pending
# TODO: Measure average duration for job archival and take number of
# pending jobs into account.
if time.time() > end_time:
break
# Returns None if the job failed to load
job = self._LoadJobUnlocked(job_id)
if job:
if job.end_timestamp is None:
if job.start_timestamp is None:
job_age = job.received_timestamp
else:
job_age = job.start_timestamp
else:
job_age = job.end_timestamp
if age == -1 or now - job_age[0] > age:
pending.append(job)
# Archive 10 jobs at a time
if len(pending) >= 10:
archived_count += self._ArchiveJobsUnlocked(pending)
pending = []
if pending:
archived_count += self._ArchiveJobsUnlocked(pending)
return (archived_count, len(all_job_ids) - last_touched)
def _Query(self, fields, qfilter):
qobj = query.Query(query.JOB_FIELDS, fields, qfilter=qfilter,
namefield="id")
job_ids = qobj.RequestedNames()
list_all = (job_ids is None)
if list_all:
# Since files are added to/removed from the queue atomically, there's no
# risk of getting the job ids in an inconsistent state.
job_ids = self._GetJobIDsUnlocked()
jobs = []
for job_id in job_ids:
job = self.SafeLoadJobFromDisk(job_id, True, writable=False)
if job is not None or not list_all:
jobs.append((job_id, job))
return (qobj, jobs, list_all)
def QueryJobs(self, fields, qfilter):
"""Returns a list of jobs in queue.
@type fields: sequence
@param fields: List of wanted fields
@type qfilter: None or query2 filter (list)
@param qfilter: Query filter
"""
(qobj, ctx, sort_by_name) = self._Query(fields, qfilter)
return query.GetQueryResponse(qobj, ctx, sort_by_name=sort_by_name)
def OldStyleQueryJobs(self, job_ids, fields):
"""Returns a list of jobs in queue.
@type job_ids: list
@param job_ids: sequence of job identifiers or None for all
@type fields: list
@param fields: names of fields to return
@rtype: list
@return: list one element per job, each element being list with
the requested fields
"""
qfilter = qlang.MakeSimpleFilter("id", job_ids)
(qobj, ctx, sort_by_name) = self._Query(fields, qfilter)
return qobj.OldStyleQuery(ctx, sort_by_name=sort_by_name)
@locking.ssynchronized(_LOCK)
def PrepareShutdown(self):
"""Prepare to stop the job queue.
Disables execution of jobs in the workerpool and returns whether there are
any jobs currently running. If the latter is the case, the job queue is not
yet ready for shutdown. Once this function returns C{True} L{Shutdown} can
be called without interfering with any job. Queued and unfinished jobs will
be resumed next time.
Once this function has been called no new job submissions will be accepted
(see L{_RequireNonDrainedQueue}).
@rtype: bool
@return: Whether there are any running jobs
"""
if self._accepting_jobs:
self._accepting_jobs = False
# Tell worker pool to stop processing pending tasks
self._wpool.SetActive(False)
return self._wpool.HasRunningTasks()
@locking.ssynchronized(_LOCK)
@_RequireOpenQueue
def Shutdown(self):
"""Stops the job queue.
This shutdowns all the worker threads an closes the queue.
"""
self._wpool.TerminateWorkers()
self._queue_filelock.Close()
self._queue_filelock = None