jqueue.py 59.5 KB
Newer Older
Iustin Pop's avatar
Iustin Pop committed
1
2
3
#
#

4
# Copyright (C) 2006, 2007, 2008, 2009, 2010 Google Inc.
Iustin Pop's avatar
Iustin Pop committed
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
#
# 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.


22
23
"""Module implementing the job queue handling.

24
25
26
27
28
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
29
30

"""
Iustin Pop's avatar
Iustin Pop committed
31

Michael Hanselmann's avatar
Michael Hanselmann committed
32
import logging
33
34
import errno
import re
35
import time
36
import weakref
Iustin Pop's avatar
Iustin Pop committed
37

Guido Trotter's avatar
Guido Trotter committed
38
39
40
41
42
43
44
try:
  # pylint: disable-msg=E0611
  from pyinotify import pyinotify
except ImportError:
  import pyinotify

from ganeti import asyncnotifier
Michael Hanselmann's avatar
Michael Hanselmann committed
45
from ganeti import constants
46
from ganeti import serializer
Michael Hanselmann's avatar
Michael Hanselmann committed
47
from ganeti import workerpool
48
from ganeti import locking
49
from ganeti import opcodes
Iustin Pop's avatar
Iustin Pop committed
50
from ganeti import errors
Michael Hanselmann's avatar
Michael Hanselmann committed
51
from ganeti import mcpu
52
from ganeti import utils
53
from ganeti import jstore
54
from ganeti import rpc
55
from ganeti import runtime
56
from ganeti import netutils
57
from ganeti import compat
Michael Hanselmann's avatar
Michael Hanselmann committed
58

59

60
JOBQUEUE_THREADS = 25
61
JOBS_PER_ARCHIVE_DIRECTORY = 10000
Michael Hanselmann's avatar
Michael Hanselmann committed
62

63
64
65
# member lock names to be passed to @ssynchronized decorator
_LOCK = "_lock"
_QUEUE = "_queue"
66

Iustin Pop's avatar
Iustin Pop committed
67

68
class CancelJob(Exception):
69
70
71
72
73
  """Special exception to cancel a job.

  """


74
def TimeStampNow():
75
76
77
78
79
80
  """Returns the current timestamp.

  @rtype: tuple
  @return: the current time in the (seconds, microseconds) format

  """
81
82
83
  return utils.SplitTime(time.time())


Michael Hanselmann's avatar
Michael Hanselmann committed
84
class _QueuedOpCode(object):
Michael Hanselmann's avatar
Michael Hanselmann committed
85
  """Encapsulates an opcode object.
Michael Hanselmann's avatar
Michael Hanselmann committed
86

87
88
89
90
91
92
  @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
Iustin Pop's avatar
Iustin Pop committed
93
  @ivar exec_timestamp: timestamp for the actual LU Exec() function invocation
94
  @ivar stop_timestamp: timestamp for the end of the execution
95

Michael Hanselmann's avatar
Michael Hanselmann committed
96
  """
97
  __slots__ = ["input", "status", "result", "log", "priority",
Iustin Pop's avatar
Iustin Pop committed
98
               "start_timestamp", "exec_timestamp", "end_timestamp",
99
100
               "__weakref__"]

Michael Hanselmann's avatar
Michael Hanselmann committed
101
  def __init__(self, op):
102
103
104
105
106
107
    """Constructor for the _QuededOpCode.

    @type op: L{opcodes.OpCode}
    @param op: the opcode we encapsulate

    """
Michael Hanselmann's avatar
Michael Hanselmann committed
108
109
110
111
    self.input = op
    self.status = constants.OP_STATUS_QUEUED
    self.result = None
    self.log = []
112
    self.start_timestamp = None
Iustin Pop's avatar
Iustin Pop committed
113
    self.exec_timestamp = None
114
    self.end_timestamp = None
115

116
117
118
    # Get initial priority (it might change during the lifetime of this opcode)
    self.priority = getattr(op, "priority", constants.OP_PRIO_DEFAULT)

119
120
  @classmethod
  def Restore(cls, state):
121
122
123
124
125
126
127
128
    """Restore the _QueuedOpCode from the serialized form.

    @type state: dict
    @param state: the serialized state
    @rtype: _QueuedOpCode
    @return: a new _QueuedOpCode instance

    """
Michael Hanselmann's avatar
Michael Hanselmann committed
129
130
131
132
133
    obj = _QueuedOpCode.__new__(cls)
    obj.input = opcodes.OpCode.LoadOpCode(state["input"])
    obj.status = state["status"]
    obj.result = state["result"]
    obj.log = state["log"]
134
    obj.start_timestamp = state.get("start_timestamp", None)
Iustin Pop's avatar
Iustin Pop committed
135
    obj.exec_timestamp = state.get("exec_timestamp", None)
136
    obj.end_timestamp = state.get("end_timestamp", None)
137
    obj.priority = state.get("priority", constants.OP_PRIO_DEFAULT)
138
139
140
    return obj

  def Serialize(self):
141
142
143
144
145
146
    """Serializes this _QueuedOpCode.

    @rtype: dict
    @return: the dictionary holding the serialized state

    """
147
148
149
150
151
    return {
      "input": self.input.__getstate__(),
      "status": self.status,
      "result": self.result,
      "log": self.log,
152
      "start_timestamp": self.start_timestamp,
Iustin Pop's avatar
Iustin Pop committed
153
      "exec_timestamp": self.exec_timestamp,
154
      "end_timestamp": self.end_timestamp,
155
      "priority": self.priority,
156
      }
157

Michael Hanselmann's avatar
Michael Hanselmann committed
158
159
160
161

class _QueuedJob(object):
  """In-memory job representation.

162
163
164
165
166
167
168
169
170
171
172
173
174
  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
Michael Hanselmann's avatar
Michael Hanselmann committed
175
176

  """
Iustin Pop's avatar
Iustin Pop committed
177
  # pylint: disable-msg=W0212
178
  __slots__ = ["queue", "id", "ops", "log_serial", "ops_iter", "cur_opctx",
179
180
181
               "received_timestamp", "start_timestamp", "end_timestamp",
               "__weakref__"]

Michael Hanselmann's avatar
Michael Hanselmann committed
182
  def __init__(self, queue, job_id, ops):
183
184
185
186
187
188
189
190
191
192
193
    """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

    """
Michael Hanselmann's avatar
Michael Hanselmann committed
194
    if not ops:
Guido Trotter's avatar
Guido Trotter committed
195
      raise errors.GenericError("A job needs at least one opcode")
Michael Hanselmann's avatar
Michael Hanselmann committed
196

Michael Hanselmann's avatar
Michael Hanselmann committed
197
    self.queue = queue
198
    self.id = job_id
Michael Hanselmann's avatar
Michael Hanselmann committed
199
    self.ops = [_QueuedOpCode(op) for op in ops]
200
    self.log_serial = 0
201
202
203
    self.received_timestamp = TimeStampNow()
    self.start_timestamp = None
    self.end_timestamp = None
204

205
206
207
208
209
210
211
    self._InitInMemory(self)

  @staticmethod
  def _InitInMemory(obj):
    """Initializes in-memory variables.

    """
212
    obj.ops_iter = None
213
    obj.cur_opctx = None
214

215
216
217
218
219
220
221
  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))

222
  @classmethod
Michael Hanselmann's avatar
Michael Hanselmann committed
223
  def Restore(cls, queue, state):
224
225
226
227
228
229
230
231
232
233
    """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
    @rtype: _JobQueue
    @return: the restored _JobQueue instance

    """
Michael Hanselmann's avatar
Michael Hanselmann committed
234
235
236
    obj = _QueuedJob.__new__(cls)
    obj.queue = queue
    obj.id = state["id"]
237
238
239
    obj.received_timestamp = state.get("received_timestamp", None)
    obj.start_timestamp = state.get("start_timestamp", None)
    obj.end_timestamp = state.get("end_timestamp", None)
240
241
242
243
244
245
246
247
248

    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)

249
    cls._InitInMemory(obj)
250

251
252
253
    return obj

  def Serialize(self):
254
255
256
257
258
259
    """Serialize the _JobQueue instance.

    @rtype: dict
    @return: the serialized state

    """
260
261
    return {
      "id": self.id,
Michael Hanselmann's avatar
Michael Hanselmann committed
262
      "ops": [op.Serialize() for op in self.ops],
263
264
265
      "start_timestamp": self.start_timestamp,
      "end_timestamp": self.end_timestamp,
      "received_timestamp": self.received_timestamp,
266
267
      }

Michael Hanselmann's avatar
Michael Hanselmann committed
268
  def CalcStatus(self):
269
270
271
272
273
274
275
276
277
278
    """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
279
          - canceling
280
281
282
283
284
285
286
287
288
289
          - 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

    """
Michael Hanselmann's avatar
Michael Hanselmann committed
290
291
292
    status = constants.JOB_STATUS_QUEUED

    all_success = True
Michael Hanselmann's avatar
Michael Hanselmann committed
293
294
    for op in self.ops:
      if op.status == constants.OP_STATUS_SUCCESS:
Michael Hanselmann's avatar
Michael Hanselmann committed
295
296
297
298
        continue

      all_success = False

Michael Hanselmann's avatar
Michael Hanselmann committed
299
      if op.status == constants.OP_STATUS_QUEUED:
Michael Hanselmann's avatar
Michael Hanselmann committed
300
        pass
Iustin Pop's avatar
Iustin Pop committed
301
302
      elif op.status == constants.OP_STATUS_WAITLOCK:
        status = constants.JOB_STATUS_WAITLOCK
Michael Hanselmann's avatar
Michael Hanselmann committed
303
      elif op.status == constants.OP_STATUS_RUNNING:
Michael Hanselmann's avatar
Michael Hanselmann committed
304
        status = constants.JOB_STATUS_RUNNING
305
306
307
      elif op.status == constants.OP_STATUS_CANCELING:
        status = constants.JOB_STATUS_CANCELING
        break
Michael Hanselmann's avatar
Michael Hanselmann committed
308
      elif op.status == constants.OP_STATUS_ERROR:
309
310
311
        status = constants.JOB_STATUS_ERROR
        # The whole job fails if one opcode failed
        break
Michael Hanselmann's avatar
Michael Hanselmann committed
312
      elif op.status == constants.OP_STATUS_CANCELED:
313
314
        status = constants.OP_STATUS_CANCELED
        break
Michael Hanselmann's avatar
Michael Hanselmann committed
315
316
317
318
319
320

    if all_success:
      status = constants.JOB_STATUS_SUCCESS

    return status

321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
  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)

339
  def GetLogEntries(self, newer_than):
340
341
342
    """Selectively returns the log entries.

    @type newer_than: None or int
Michael Hanselmann's avatar
Michael Hanselmann committed
343
    @param newer_than: if this is None, return all log entries,
344
345
346
347
348
349
        otherwise return only the log entries with serial higher
        than this value
    @rtype: list
    @return: the list of the log entries selected

    """
350
351
352
353
354
355
356
    if newer_than is None:
      serial = -1
    else:
      serial = newer_than

    entries = []
    for op in self.ops:
357
      entries.extend(filter(lambda entry: entry[0] > serial, op.log))
358
359
360

    return entries

361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
  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

    """
    row = []
    for fname in fields:
      if fname == "id":
        row.append(self.id)
      elif fname == "status":
        row.append(self.CalcStatus())
378
379
      elif fname == "priority":
        row.append(self.CalcPriority())
380
381
382
383
384
385
386
387
388
389
390
391
392
393
      elif fname == "ops":
        row.append([op.input.__getstate__() for op in self.ops])
      elif fname == "opresult":
        row.append([op.result for op in self.ops])
      elif fname == "opstatus":
        row.append([op.status for op in self.ops])
      elif fname == "oplog":
        row.append([op.log for op in self.ops])
      elif fname == "opstart":
        row.append([op.start_timestamp for op in self.ops])
      elif fname == "opexec":
        row.append([op.exec_timestamp for op in self.ops])
      elif fname == "opend":
        row.append([op.end_timestamp for op in self.ops])
394
395
      elif fname == "oppriority":
        row.append([op.priority for op in self.ops])
396
397
398
399
400
401
402
403
404
405
406
407
      elif fname == "received_ts":
        row.append(self.received_timestamp)
      elif fname == "start_ts":
        row.append(self.start_timestamp)
      elif fname == "end_ts":
        row.append(self.end_timestamp)
      elif fname == "summary":
        row.append([op.input.Summary() for op in self.ops])
      else:
        raise errors.OpExecError("Invalid self query field '%s'" % fname)
    return row

408
409
410
411
412
413
414
415
416
417
418
  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

    """
419
420
421
422
423
424
425
426
    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
427

428
429
430
431
432
433
  def Finalize(self):
    """Marks the job as finalized.

    """
    self.end_timestamp = TimeStampNow()

434
  def Cancel(self):
435
436
437
438
439
440
441
    """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

    """
442
443
444
445
446
    status = self.CalcStatus()

    if status == constants.JOB_STATUS_QUEUED:
      self.MarkUnfinishedOps(constants.OP_STATUS_CANCELED,
                             "Job canceled by request")
447
      self.Finalize()
448
      return (True, "Job %s canceled" % self.id)
449
450
451
452

    elif status == constants.JOB_STATUS_WAITLOCK:
      # The worker will notice the new status and cancel the job
      self.MarkUnfinishedOps(constants.OP_STATUS_CANCELING, None)
453
      return (True, "Job %s will be canceled" % self.id)
454

455
456
457
    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)
458

459

460
class _OpExecCallbacks(mcpu.OpExecCbBase):
461
462
  def __init__(self, queue, job, op):
    """Initializes this class.
463

464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
    @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

480
481
482
483
484
485
486
487
488
  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()

489
  @locking.ssynchronized(_QUEUE, shared=1)
490
  def NotifyStart(self):
Iustin Pop's avatar
Iustin Pop committed
491
492
    """Mark the opcode as running, not lock-waiting.

493
494
495
496
    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_WAITLOCK.
Iustin Pop's avatar
Iustin Pop committed
497
498

    """
499
    assert self._op in self._job.ops
500
501
    assert self._op.status in (constants.OP_STATUS_WAITLOCK,
                               constants.OP_STATUS_CANCELING)
502

503
    # Cancel here if we were asked to
504
    self._CheckCancel()
505

506
    logging.debug("Opcode is now running")
507

508
509
510
511
512
    self._op.status = constants.OP_STATUS_RUNNING
    self._op.exec_timestamp = TimeStampNow()

    # And finally replicate the job status
    self._queue.UpdateJobUnlocked(self._job)
513

514
  @locking.ssynchronized(_QUEUE, shared=1)
515
516
517
518
519
520
521
522
  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)

523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
  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())
538
    self._AppendFeedback(timestamp, log_type, log_msg)
539

540
541
  def CheckCancel(self):
    """Check whether job has been cancelled.
542
543

    """
544
545
546
547
548
549
    assert self._op.status in (constants.OP_STATUS_WAITLOCK,
                               constants.OP_STATUS_CANCELING)

    # Cancel here if we were asked to
    self._CheckCancel()

550
551
552
553
554
555
556
557
558
  def SubmitManyJobs(self, jobs):
    """Submits jobs for processing.

    See L{JobQueue.SubmitManyJobs}.

    """
    # Locking is done in job queue
    return self._queue.SubmitManyJobs(jobs)

559

560
561
562
class _JobChangesChecker(object):
  def __init__(self, fields, prev_job_info, prev_log_serial):
    """Initializes this class.
Guido Trotter's avatar
Guido Trotter committed
563

564
565
566
567
568
569
    @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
Guido Trotter's avatar
Guido Trotter committed
570

571
572
573
574
    """
    self._fields = fields
    self._prev_job_info = prev_job_info
    self._prev_log_serial = prev_log_serial
Guido Trotter's avatar
Guido Trotter committed
575

576
577
  def __call__(self, job):
    """Checks whether job has changed.
Guido Trotter's avatar
Guido Trotter committed
578

579
580
    @type job: L{_QueuedJob}
    @param job: Job object
Guido Trotter's avatar
Guido Trotter committed
581
582

    """
583
584
585
    status = job.CalcStatus()
    job_info = job.GetInfo(self._fields)
    log_entries = job.GetLogEntries(self._prev_log_serial)
Guido Trotter's avatar
Guido Trotter committed
586
587
588
589
590
591
592
593

    # 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.
594
595
596
597
    # 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))
Guido Trotter's avatar
Guido Trotter committed
598
599
600

    # Don't even try to wait if the job is no longer running, there will be
    # no changes.
601
602
603
604
605
606
607
    if (status not in (constants.JOB_STATUS_QUEUED,
                       constants.JOB_STATUS_RUNNING,
                       constants.JOB_STATUS_WAITLOCK) 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)
Guido Trotter's avatar
Guido Trotter committed
608

609
610
611
612
613
614
615
616
617
618
    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
Guido Trotter's avatar
Guido Trotter committed
619

620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
    """
    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.

    """
Guido Trotter's avatar
Guido Trotter committed
637
    if not notifier_enabled:
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
      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
Guido Trotter's avatar
Guido Trotter committed
672

673
674
  def Wait(self, timeout):
    """Waits for a job to change.
Guido Trotter's avatar
Guido Trotter committed
675

676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
    @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(job_load_fn, check_fn):
    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

    """
Guido Trotter's avatar
Guido Trotter committed
737
    try:
738
739
740
741
742
743
744
745
746
      check_fn = _JobChangesChecker(fields, prev_job_info, prev_log_serial)
      waiter = _JobChangesWaiter(filename)
      try:
        return utils.Retry(compat.partial(self._CheckForChanges,
                                          job_load_fn, check_fn),
                           utils.RETRY_REMAINING_TIME, timeout,
                           wait_fn=waiter.Wait)
      finally:
        waiter.Close()
Guido Trotter's avatar
Guido Trotter committed
747
748
749
750
751
752
    except (errors.InotifyError, errors.JobLost):
      return None
    except utils.RetryTimeout:
      return constants.JOB_NOTCHANGED


753
754
755
756
757
758
759
760
761
762
763
764
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)


765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
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


797
class _OpExecContext:
798
  def __init__(self, op, index, log_prefix, timeout_strategy_factory):
799
800
801
802
803
804
805
806
    """Initializes this class.

    """
    self.op = op
    self.index = index
    self.log_prefix = log_prefix
    self.summary = op.input.Summary()

807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
    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()

842

843
class _JobProcessor(object):
844
845
  def __init__(self, queue, opexec_fn, job,
               _timeout_strategy_factory=mcpu.LockAttemptTimeoutStrategy):
846
847
848
849
850
851
    """Initializes this class.

    """
    self.queue = queue
    self.opexec_fn = opexec_fn
    self.job = job
852
    self._timeout_strategy_factory = _timeout_strategy_factory
853
854

  @staticmethod
855
  def _FindNextOpcode(job, timeout_strategy_factory):
856
857
858
859
    """Locates the next opcode to run.

    @type job: L{_QueuedJob}
    @param job: Job object
860
    @param timeout_strategy_factory: Callable to create new timeout strategy
861
862
863
864
865
866

    """
    # 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.
867
868
    if job.ops_iter is None:
      job.ops_iter = enumerate(job.ops)
869
870
871
872

    # Find next opcode to run
    while True:
      try:
873
        (idx, op) = job.ops_iter.next()
874
875
876
877
878
879
880
      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")

881
882
      opctx = _OpExecContext(op, idx, "Op %s/%s" % (idx + 1, len(job.ops)),
                             timeout_strategy_factory)
883

884
885
      if op.status not in constants.OPS_FINALIZED:
        return opctx
886

887
888
889
890
891
892
      # 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)
893
894
895
896
897
898
899
900
901

  @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
902
903
    @type op: L{_QueuedOpCode}
    @param op: Opcode object
904
905
906

    """
    assert op in job.ops
907
908
909
910
    assert op.status in (constants.OP_STATUS_QUEUED,
                         constants.OP_STATUS_WAITLOCK)

    update = False
911
912

    op.result = None
913
914
915
916
917
918
919
920

    if op.status == constants.OP_STATUS_QUEUED:
      op.status = constants.OP_STATUS_WAITLOCK
      update = True

    if op.start_timestamp is None:
      op.start_timestamp = TimeStampNow()
      update = True
921
922
923

    if job.start_timestamp is None:
      job.start_timestamp = op.start_timestamp
924
925
926
927
928
      update = True

    assert op.status == constants.OP_STATUS_WAITLOCK

    return update
929

930
  def _ExecOpCodeUnlocked(self, opctx):
931
932
933
    """Processes one opcode and returns the result.

    """
934
935
    op = opctx.op

936
937
    assert op.status == constants.OP_STATUS_WAITLOCK

938
939
    timeout = opctx.GetNextLockTimeout()

940
941
942
    try:
      # Make sure not to hold queue lock while calling ExecOpCode
      result = self.opexec_fn(op.input,
943
                              _OpExecCallbacks(self.queue, self.job, op),
944
                              timeout=timeout, priority=op.priority)
945
946
947
    except mcpu.LockAcquireTimeout:
      assert timeout is not None, "Received timeout for blocking acquire"
      logging.debug("Couldn't acquire locks in %0.6fs", timeout)
948
949
950
951
952
953
954
955

      assert op.status in (constants.OP_STATUS_WAITLOCK,
                           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)

956
957
      # Stay in waitlock while trying to re-acquire lock
      return (constants.OP_STATUS_WAITLOCK, None)
958
    except CancelJob:
959
      logging.exception("%s: Canceling job", opctx.log_prefix)
960
961
962
      assert op.status == constants.OP_STATUS_CANCELING
      return (constants.OP_STATUS_CANCELING, None)
    except Exception, err: # pylint: disable-msg=W0703
963
964
      logging.exception("%s: Caught exception in %s",
                        opctx.log_prefix, opctx.summary)
965
966
      return (constants.OP_STATUS_ERROR, _EncodeOpError(err))
    else:
967
968
      logging.debug("%s: %s successful",
                    opctx.log_prefix, opctx.summary)
969
970
      return (constants.OP_STATUS_SUCCESS, result)

971
  def __call__(self, _nextop_fn=None):
972
973
    """Continues execution of a job.

974
    @param _nextop_fn: Callback function for tests
975
976
977
978
979
980
981
982
983
984
985
986
987
988
    @rtype: bool
    @return: True if job is finished, False if processor needs to be called
             again

    """
    queue = self.queue
    job = self.job

    logging.debug("Processing job %s", job.id)

    queue.acquire(shared=1)
    try:
      opcount = len(job.ops)

989
990
991
992
      # Don't do anything for finalized jobs
      if job.CalcStatus() in constants.JOBS_FINALIZED:
        return True

993
994
995
      # Is a previous opcode still pending?
      if job.cur_opctx:
        opctx = job.cur_opctx
996
        job.cur_opctx = None
997
998
999
1000
1001
      else:
        if __debug__ and _nextop_fn:
          _nextop_fn()
        opctx = self._FindNextOpcode(job, self._timeout_strategy_factory)

1002
      op = opctx.op
1003
1004
1005

      # Consistency check
      assert compat.all(i.status in (constants.OP_STATUS_QUEUED,
1006
                                     constants.OP_STATUS_CANCELING)
1007
                        for i in job.ops[opctx.index + 1:])
1008
1009
1010

      assert op.status in (constants.OP_STATUS_QUEUED,
                           constants.OP_STATUS_WAITLOCK,
1011
                           constants.OP_STATUS_CANCELING)
1012

1013
1014
1015
      assert (op.priority <= constants.OP_PRIO_LOWEST and
              op.priority >= constants.OP_PRIO_HIGHEST)

1016
      if op.status != constants.OP_STATUS_CANCELING:
1017
1018
1019
        assert op.status in (constants.OP_STATUS_QUEUED,
                             constants.OP_STATUS_WAITLOCK)

1020
        # Prepare to start opcode
1021
1022
1023
        if self._MarkWaitlock(job, op):
          # Write to disk
          queue.UpdateJobUnlocked(job)
1024
1025
1026

        assert op.status == constants.OP_STATUS_WAITLOCK
        assert job.CalcStatus() == constants.JOB_STATUS_WAITLOCK
1027
        assert job.start_timestamp and op.start_timestamp
1028

1029
1030
        logging.info("%s: opcode %s waiting for locks",
                     opctx.log_prefix, opctx.summary)
1031
1032
1033

        queue.release()
        try:
1034
          (op_status, op_result) = self._ExecOpCodeUnlocked(opctx)
1035
1036
1037
1038
1039
1040
        finally:
          queue.acquire(shared=1)

        op.status = op_status
        op.result = op_result

1041
        if op.status == constants.OP_STATUS_WAITLOCK:
1042
1043
          # Couldn't get locks in time
          assert not op.end_timestamp
1044
        else:
1045
1046
          # Finalize opcode
          op.end_timestamp = TimeStampNow()
1047

1048
1049
1050
1051
1052
          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
1053

1054
      if op.status == constants.OP_STATUS_WAITLOCK:
1055
1056
        finalize = False

1057
1058
1059
        if opctx.CheckPriorityIncrease():
          # Priority was changed, need to update on-disk file
          queue.UpdateJobUnlocked(job)
1060

1061
1062
        # Keep around for another round
        job.cur_opctx = opctx
1063

1064
1065
        assert (op.priority <= constants.OP_PRIO_LOWEST and
                op.priority >= constants.OP_PRIO_HIGHEST)
1066

1067
        # In no case must the status be finalized here
1068
        assert job.CalcStatus() == constants.JOB_STATUS_WAITLOCK
1069
1070

      else:
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
        # 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
1090

1091
1092
1093
1094
          # Consistency check
          assert compat.all(i.status == constants.OP_STATUS_ERROR and
                            errors.GetEncodedError(i.result)
                            for i in job.ops[opctx.index:])
1095

1096
1097
1098
1099
1100
1101
1102
1103
        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)

1104
1105
1106
1107
1108
        if opctx.index == (opcount - 1):
          # Finalize on last opcode
          finalize = True

        if finalize:
1109
          # All opcodes have been run, finalize job
1110
          job.Finalize()
1111
1112
1113
1114

        # 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)
1115

1116
        if finalize:
1117
1118
          logging.info("Finished job %s, status = %s", job.id, job.CalcStatus())
          return True
1119
1120
1121
1122
1123
1124

      return False
    finally:
      queue.release()


1125
1126
1127
1128
class _JobQueueWorker(workerpool.BaseWorker):
  """The actual job workers.

  """
Iustin Pop's avatar
Iustin Pop committed
1129
  def RunTask(self, job): # pylint: disable-msg=W0221
Michael Hanselmann's avatar
Michael Hanselmann committed
1130
1131
    """Job executor.

1132
1133
    This functions processes a job. It is closely tied to the L{_QueuedJob} and
    L{_QueuedOpCode} classes.
Michael Hanselmann's avatar
Michael Hanselmann committed
1134

1135
1136
1137
    @type job: L{_QueuedJob}
    @param job: the job to be processed

Michael Hanselmann's avatar
Michael Hanselmann committed
1138
    """
1139
1140
1141
    queue = job.queue
    assert queue == self.pool.queue

1142
1143
    setname_fn = lambda op: self.SetTaskName(self._GetWorkerName(job, op))
    setname_fn(None)
1144

1145
1146
    proc = mcpu.Processor(queue.context, job.id)

1147
1148
1149
1150
1151
    # Create wrapper for setting thread name
    wrap_execop_fn = compat.partial(self._WrapExecOpCode, setname_fn,
                                    proc.ExecOpCode)

    if not _JobProcessor(queue, wrap_execop_fn, job)():
1152
      # Schedule again
1153
      raise workerpool.DeferTask(priority=job.CalcPriority())
Michael Hanselmann's avatar
Michael Hanselmann committed
1154

1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
  @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)

Michael Hanselmann's avatar
Michael Hanselmann committed
1185
1186

class _JobQueueWorkerPool(workerpool.WorkerPool):
1187
1188
1189
  """Simple class implementing a job-processing workerpool.

  """
1190
  def __init__(self, queue):
1191
    super(_JobQueueWorkerPool, self).__init__("Jq",
1192
                                              JOBQUEUE_THREADS,
Michael Hanselmann's avatar
Michael Hanselmann committed
1193
                                              _JobQueueWorker)
1194
    self.queue = queue
Michael Hanselmann's avatar
Michael Hanselmann committed
1195
1196


Iustin Pop's avatar
Iustin Pop committed
1197
1198
def _RequireOpenQueue(fn):
  """Decorator for "public" functions.
1199

Iustin Pop's avatar
Iustin Pop committed
1200
1201
1202
1203
  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
1204
  a '_queue_filelock' argument.
1205

1206
  @warning: Use this decorator only after locking.ssynchronized
1207

Iustin Pop's avatar
Iustin Pop committed
1208
  Example::
1209
    @locking.ssynchronized(_LOCK)
Iustin Pop's avatar
Iustin Pop committed
1210
1211
1212
    @_RequireOpenQueue
    def Example(self):
      pass
1213

Iustin Pop's avatar
Iustin Pop committed
1214
1215
  """
  def wrapper(self, *args, **kwargs):
Iustin Pop's avatar
Iustin Pop committed
1216
    # pylint: disable-msg=W0212
1217
    assert self._queue_filelock is not None, "Queue should be open"
Iustin Pop's avatar
Iustin Pop committed
1218
1219
    return fn(self, *args, **kwargs)
  return wrapper
1220
1221


Iustin Pop's avatar
Iustin Pop committed
1222
1223
class JobQueue(object):
  """Queue used to manage the jobs.
1224

Iustin Pop's avatar
Iustin Pop committed
1225
1226
1227
1228
  @cvar _RE_JOB_FILE: regex matching the valid job file names

  """
  _RE_JOB_FILE = re.compile(r"^job-(%s)$" % constants.JOB_ID_TEMPLATE)
1229

Michael Hanselmann's avatar
Michael Hanselmann committed
1230
  def __init__(self, context):
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
    """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

    """
1243
    self.context = context
1244
    self._memcache = weakref.WeakValueDictionary()
1245
    self._my_hostname = netutils.Hostname.GetSysName()
1246

1247
1248
1249
1250
1251
    # 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.
1252
    self._lock = locking.SharedLock("JobQueue")
1253
1254
1255

    self.acquire = self._lock.acquire
    self.release = self._lock.release
Michael Hanselmann's avatar
Michael Hanselmann committed
1256

1257
1258
1259
    # 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)
1260

1261
1262
1263
1264
    # 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")
1265

1266
    # Get initial list of nodes
1267
    self._nodes = dict((n.name, n.primary_ip)
1268
1269
                       for n in self.context.cfg.GetAllNodesInfo().values()
                       if n.master_candidate)
Michael Hanselmann's avatar