jqueue.py 50.2 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

32
import os
Michael Hanselmann's avatar
Michael Hanselmann committed
33
import logging
34
35
import errno
import re
36
import time
37
import weakref
Iustin Pop's avatar
Iustin Pop committed
38

Guido Trotter's avatar
Guido Trotter committed
39
40
41
42
43
44
45
try:
  # pylint: disable-msg=E0611
  from pyinotify import pyinotify
except ImportError:
  import pyinotify

from ganeti import asyncnotifier
Michael Hanselmann's avatar
Michael Hanselmann committed
46
from ganeti import constants
47
from ganeti import serializer
Michael Hanselmann's avatar
Michael Hanselmann committed
48
from ganeti import workerpool
49
from ganeti import locking
50
from ganeti import opcodes
Iustin Pop's avatar
Iustin Pop committed
51
from ganeti import errors
Michael Hanselmann's avatar
Michael Hanselmann committed
52
from ganeti import mcpu
53
from ganeti import utils
54
from ganeti import jstore
55
from ganeti import rpc
56
from ganeti import runtime
57
from ganeti import netutils
58
from ganeti import compat
Michael Hanselmann's avatar
Michael Hanselmann committed
59

60

61
JOBQUEUE_THREADS = 25
62
JOBS_PER_ARCHIVE_DIRECTORY = 10000
Michael Hanselmann's avatar
Michael Hanselmann committed
63

64
65
66
# member lock names to be passed to @ssynchronized decorator
_LOCK = "_lock"
_QUEUE = "_queue"
67

Iustin Pop's avatar
Iustin Pop committed
68

69
class CancelJob(Exception):
70
71
72
73
74
  """Special exception to cancel a job.

  """


75
def TimeStampNow():
76
77
78
79
80
81
  """Returns the current timestamp.

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

  """
82
83
84
  return utils.SplitTime(time.time())


Michael Hanselmann's avatar
Michael Hanselmann committed
85
class _QueuedOpCode(object):
Michael Hanselmann's avatar
Michael Hanselmann committed
86
  """Encapsulates an opcode object.
Michael Hanselmann's avatar
Michael Hanselmann committed
87

88
89
90
91
92
93
  @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
94
  @ivar exec_timestamp: timestamp for the actual LU Exec() function invocation
95
  @ivar stop_timestamp: timestamp for the end of the execution
96

Michael Hanselmann's avatar
Michael Hanselmann committed
97
  """
98
  __slots__ = ["input", "status", "result", "log", "priority",
Iustin Pop's avatar
Iustin Pop committed
99
               "start_timestamp", "exec_timestamp", "end_timestamp",
100
101
               "__weakref__"]

Michael Hanselmann's avatar
Michael Hanselmann committed
102
  def __init__(self, op):
103
104
105
106
107
108
    """Constructor for the _QuededOpCode.

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

    """
Michael Hanselmann's avatar
Michael Hanselmann committed
109
110
111
112
    self.input = op
    self.status = constants.OP_STATUS_QUEUED
    self.result = None
    self.log = []
113
    self.start_timestamp = None
Iustin Pop's avatar
Iustin Pop committed
114
    self.exec_timestamp = None
115
    self.end_timestamp = None
116

117
118
119
    # Get initial priority (it might change during the lifetime of this opcode)
    self.priority = getattr(op, "priority", constants.OP_PRIO_DEFAULT)

120
121
  @classmethod
  def Restore(cls, state):
122
123
124
125
126
127
128
129
    """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
130
131
132
133
134
    obj = _QueuedOpCode.__new__(cls)
    obj.input = opcodes.OpCode.LoadOpCode(state["input"])
    obj.status = state["status"]
    obj.result = state["result"]
    obj.log = state["log"]
135
    obj.start_timestamp = state.get("start_timestamp", None)
Iustin Pop's avatar
Iustin Pop committed
136
    obj.exec_timestamp = state.get("exec_timestamp", None)
137
    obj.end_timestamp = state.get("end_timestamp", None)
138
    obj.priority = state.get("priority", constants.OP_PRIO_DEFAULT)
139
140
141
    return obj

  def Serialize(self):
142
143
144
145
146
147
    """Serializes this _QueuedOpCode.

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

    """
148
149
150
151
152
    return {
      "input": self.input.__getstate__(),
      "status": self.status,
      "result": self.result,
      "log": self.log,
153
      "start_timestamp": self.start_timestamp,
Iustin Pop's avatar
Iustin Pop committed
154
      "exec_timestamp": self.exec_timestamp,
155
      "end_timestamp": self.end_timestamp,
156
      "priority": self.priority,
157
      }
158

Michael Hanselmann's avatar
Michael Hanselmann committed
159
160
161
162

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

163
164
165
166
167
168
169
170
171
172
173
174
175
  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
176
177

  """
Iustin Pop's avatar
Iustin Pop committed
178
  # pylint: disable-msg=W0212
179
  __slots__ = ["queue", "id", "ops", "log_serial",
180
181
182
               "received_timestamp", "start_timestamp", "end_timestamp",
               "__weakref__"]

Michael Hanselmann's avatar
Michael Hanselmann committed
183
  def __init__(self, queue, job_id, ops):
184
185
186
187
188
189
190
191
192
193
194
    """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
195
    if not ops:
Guido Trotter's avatar
Guido Trotter committed
196
      raise errors.GenericError("A job needs at least one opcode")
Michael Hanselmann's avatar
Michael Hanselmann committed
197

Michael Hanselmann's avatar
Michael Hanselmann committed
198
    self.queue = queue
199
    self.id = job_id
Michael Hanselmann's avatar
Michael Hanselmann committed
200
    self.ops = [_QueuedOpCode(op) for op in ops]
201
    self.log_serial = 0
202
203
204
    self.received_timestamp = TimeStampNow()
    self.start_timestamp = None
    self.end_timestamp = None
205

206
207
208
209
210
211
212
  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))

213
  @classmethod
Michael Hanselmann's avatar
Michael Hanselmann committed
214
  def Restore(cls, queue, state):
215
216
217
218
219
220
221
222
223
224
    """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
225
226
227
    obj = _QueuedJob.__new__(cls)
    obj.queue = queue
    obj.id = state["id"]
228
229
230
    obj.received_timestamp = state.get("received_timestamp", None)
    obj.start_timestamp = state.get("start_timestamp", None)
    obj.end_timestamp = state.get("end_timestamp", None)
231
232
233
234
235
236
237
238
239

    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)

240
241
242
    return obj

  def Serialize(self):
243
244
245
246
247
248
    """Serialize the _JobQueue instance.

    @rtype: dict
    @return: the serialized state

    """
249
250
    return {
      "id": self.id,
Michael Hanselmann's avatar
Michael Hanselmann committed
251
      "ops": [op.Serialize() for op in self.ops],
252
253
254
      "start_timestamp": self.start_timestamp,
      "end_timestamp": self.end_timestamp,
      "received_timestamp": self.received_timestamp,
255
256
      }

Michael Hanselmann's avatar
Michael Hanselmann committed
257
  def CalcStatus(self):
258
259
260
261
262
263
264
265
266
267
    """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
268
          - canceling
269
270
271
272
273
274
275
276
277
278
          - 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
279
280
281
    status = constants.JOB_STATUS_QUEUED

    all_success = True
Michael Hanselmann's avatar
Michael Hanselmann committed
282
283
    for op in self.ops:
      if op.status == constants.OP_STATUS_SUCCESS:
Michael Hanselmann's avatar
Michael Hanselmann committed
284
285
286
287
        continue

      all_success = False

Michael Hanselmann's avatar
Michael Hanselmann committed
288
      if op.status == constants.OP_STATUS_QUEUED:
Michael Hanselmann's avatar
Michael Hanselmann committed
289
        pass
Iustin Pop's avatar
Iustin Pop committed
290
291
      elif op.status == constants.OP_STATUS_WAITLOCK:
        status = constants.JOB_STATUS_WAITLOCK
Michael Hanselmann's avatar
Michael Hanselmann committed
292
      elif op.status == constants.OP_STATUS_RUNNING:
Michael Hanselmann's avatar
Michael Hanselmann committed
293
        status = constants.JOB_STATUS_RUNNING
294
295
296
      elif op.status == constants.OP_STATUS_CANCELING:
        status = constants.JOB_STATUS_CANCELING
        break
Michael Hanselmann's avatar
Michael Hanselmann committed
297
      elif op.status == constants.OP_STATUS_ERROR:
298
299
300
        status = constants.JOB_STATUS_ERROR
        # The whole job fails if one opcode failed
        break
Michael Hanselmann's avatar
Michael Hanselmann committed
301
      elif op.status == constants.OP_STATUS_CANCELED:
302
303
        status = constants.OP_STATUS_CANCELED
        break
Michael Hanselmann's avatar
Michael Hanselmann committed
304
305
306
307
308
309

    if all_success:
      status = constants.JOB_STATUS_SUCCESS

    return status

310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
  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)

328
  def GetLogEntries(self, newer_than):
329
330
331
    """Selectively returns the log entries.

    @type newer_than: None or int
Michael Hanselmann's avatar
Michael Hanselmann committed
332
    @param newer_than: if this is None, return all log entries,
333
334
335
336
337
338
        otherwise return only the log entries with serial higher
        than this value
    @rtype: list
    @return: the list of the log entries selected

    """
339
340
341
342
343
344
345
    if newer_than is None:
      serial = -1
    else:
      serial = newer_than

    entries = []
    for op in self.ops:
346
      entries.extend(filter(lambda entry: entry[0] > serial, op.log))
347
348
349

    return entries

350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
  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())
      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])
      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

393
394
395
396
397
398
399
400
401
402
403
  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

    """
404
405
406
407
408
409
410
411
    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
412

413

414
class _OpExecCallbacks(mcpu.OpExecCbBase):
415
416
  def __init__(self, queue, job, op):
    """Initializes this class.
417

418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
    @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

434
435
436
437
438
439
440
441
442
  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()

443
  @locking.ssynchronized(_QUEUE, shared=1)
444
  def NotifyStart(self):
Iustin Pop's avatar
Iustin Pop committed
445
446
    """Mark the opcode as running, not lock-waiting.

447
448
449
450
    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
451
452

    """
453
    assert self._op in self._job.ops
454
455
    assert self._op.status in (constants.OP_STATUS_WAITLOCK,
                               constants.OP_STATUS_CANCELING)
456

457
    # Cancel here if we were asked to
458
    self._CheckCancel()
459

460
    logging.debug("Opcode is now running")
461

462
463
464
465
466
    self._op.status = constants.OP_STATUS_RUNNING
    self._op.exec_timestamp = TimeStampNow()

    # And finally replicate the job status
    self._queue.UpdateJobUnlocked(self._job)
467

468
  @locking.ssynchronized(_QUEUE, shared=1)
469
470
471
472
473
474
475
476
  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)

477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
  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())
492
    self._AppendFeedback(timestamp, log_type, log_msg)
493

494
495
  def CheckCancel(self):
    """Check whether job has been cancelled.
496
497

    """
498
499
500
501
502
503
    assert self._op.status in (constants.OP_STATUS_WAITLOCK,
                               constants.OP_STATUS_CANCELING)

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

504

505
506
507
class _JobChangesChecker(object):
  def __init__(self, fields, prev_job_info, prev_log_serial):
    """Initializes this class.
Guido Trotter's avatar
Guido Trotter committed
508

509
510
511
512
513
514
    @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
515

516
517
518
519
    """
    self._fields = fields
    self._prev_job_info = prev_job_info
    self._prev_log_serial = prev_log_serial
Guido Trotter's avatar
Guido Trotter committed
520

521
522
  def __call__(self, job):
    """Checks whether job has changed.
Guido Trotter's avatar
Guido Trotter committed
523

524
525
    @type job: L{_QueuedJob}
    @param job: Job object
Guido Trotter's avatar
Guido Trotter committed
526
527

    """
528
529
530
    status = job.CalcStatus()
    job_info = job.GetInfo(self._fields)
    log_entries = job.GetLogEntries(self._prev_log_serial)
Guido Trotter's avatar
Guido Trotter committed
531
532
533
534
535
536
537
538

    # 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.
539
540
541
542
    # 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
543
544
545

    # Don't even try to wait if the job is no longer running, there will be
    # no changes.
546
547
548
549
550
551
552
    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
553

554
555
556
557
558
559
560
561
562
563
    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
564

565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
    """
    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
582
    if not notifier_enabled:
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
      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
617

618
619
  def Wait(self, timeout):
    """Waits for a job to change.
Guido Trotter's avatar
Guido Trotter committed
620

621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
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
672
673
674
675
676
677
678
679
680
681
    @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
682
    try:
683
684
685
686
687
688
689
690
691
      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
692
693
694
695
696
697
    except (errors.InotifyError, errors.JobLost):
      return None
    except utils.RetryTimeout:
      return constants.JOB_NOTCHANGED


698
699
700
701
702
703
704
705
706
707
708
709
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)


710
711
712
713
class _JobQueueWorker(workerpool.BaseWorker):
  """The actual job workers.

  """
Iustin Pop's avatar
Iustin Pop committed
714
  def RunTask(self, job): # pylint: disable-msg=W0221
Michael Hanselmann's avatar
Michael Hanselmann committed
715
716
    """Job executor.

717
718
    This functions processes a job. It is closely tied to the _QueuedJob and
    _QueuedOpCode classes.
Michael Hanselmann's avatar
Michael Hanselmann committed
719

720
721
722
    @type job: L{_QueuedJob}
    @param job: the job to be processed

Michael Hanselmann's avatar
Michael Hanselmann committed
723
    """
724
725
    self.SetTaskName("Job%s" % job.id)

726
    logging.info("Processing job %s", job.id)
727
    proc = mcpu.Processor(self.pool.queue.context, job.id)
728
    queue = job.queue
Michael Hanselmann's avatar
Michael Hanselmann committed
729
    try:
Michael Hanselmann's avatar
Michael Hanselmann committed
730
731
732
      try:
        count = len(job.ops)
        for idx, op in enumerate(job.ops):
733
          op_summary = op.input.Summary()
734
735
736
737
738
739
740
741
742
          if op.status == constants.OP_STATUS_SUCCESS:
            # 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("Op %s/%s: opcode %s already processed, skipping",
                         idx + 1, count, op_summary)
            continue
Michael Hanselmann's avatar
Michael Hanselmann committed
743
          try:
744
745
            logging.info("Op %s/%s: Starting opcode %s", idx + 1, count,
                         op_summary)
Michael Hanselmann's avatar
Michael Hanselmann committed
746

747
            queue.acquire(shared=1)
Michael Hanselmann's avatar
Michael Hanselmann committed
748
            try:
749
              if op.status == constants.OP_STATUS_CANCELED:
750
                logging.debug("Canceling opcode")
751
                raise CancelJob()
752
              assert op.status == constants.OP_STATUS_QUEUED
753
754
              logging.debug("Opcode %s/%s waiting for locks",
                            idx + 1, count)
Iustin Pop's avatar
Iustin Pop committed
755
              op.status = constants.OP_STATUS_WAITLOCK
Michael Hanselmann's avatar
Michael Hanselmann committed
756
              op.result = None
757
              op.start_timestamp = TimeStampNow()
758
759
              if idx == 0: # first opcode
                job.start_timestamp = op.start_timestamp
Michael Hanselmann's avatar
Michael Hanselmann committed
760
761
              queue.UpdateJobUnlocked(job)

Iustin Pop's avatar
Iustin Pop committed
762
              input_opcode = op.input
Michael Hanselmann's avatar
Michael Hanselmann committed
763
764
765
            finally:
              queue.release()

766
767
            # Make sure not to hold queue lock while calling ExecOpCode
            result = proc.ExecOpCode(input_opcode,
768
                                     _OpExecCallbacks(queue, job, op))
Michael Hanselmann's avatar
Michael Hanselmann committed
769

770
            queue.acquire(shared=1)
Michael Hanselmann's avatar
Michael Hanselmann committed
771
            try:
772
              logging.debug("Opcode %s/%s succeeded", idx + 1, count)
Michael Hanselmann's avatar
Michael Hanselmann committed
773
774
              op.status = constants.OP_STATUS_SUCCESS
              op.result = result
775
              op.end_timestamp = TimeStampNow()
776
777
              if idx == count - 1:
                job.end_timestamp = TimeStampNow()
778
779
780
781
782

                # Consistency check
                assert compat.all(i.status == constants.OP_STATUS_SUCCESS
                                  for i in job.ops)

Michael Hanselmann's avatar
Michael Hanselmann committed
783
784
785
786
              queue.UpdateJobUnlocked(job)
            finally:
              queue.release()

787
788
            logging.info("Op %s/%s: Successfully finished opcode %s",
                         idx + 1, count, op_summary)
789
790
791
          except CancelJob:
            # Will be handled further up
            raise
Michael Hanselmann's avatar
Michael Hanselmann committed
792
          except Exception, err:
793
            queue.acquire(shared=1)
Michael Hanselmann's avatar
Michael Hanselmann committed
794
795
            try:
              try:
796
                logging.debug("Opcode %s/%s failed", idx + 1, count)
Michael Hanselmann's avatar
Michael Hanselmann committed
797
                op.status = constants.OP_STATUS_ERROR
798
                op.result = _EncodeOpError(err)
799
                op.end_timestamp = TimeStampNow()
800
801
                logging.info("Op %s/%s: Error in opcode %s: %s",
                             idx + 1, count, op_summary, err)
802
803
804

                to_encode = errors.OpExecError("Preceding opcode failed")
                job.MarkUnfinishedOps(constants.OP_STATUS_ERROR,
805
                                      _EncodeOpError(to_encode))
806
807
808
809
810
811
812

                # Consistency check
                assert compat.all(i.status == constants.OP_STATUS_SUCCESS
                                  for i in job.ops[:idx])
                assert compat.all(i.status == constants.OP_STATUS_ERROR and
                                  errors.GetEncodedError(i.result)
                                  for i in job.ops[idx:])
Michael Hanselmann's avatar
Michael Hanselmann committed
813
              finally:
814
                job.end_timestamp = TimeStampNow()
Michael Hanselmann's avatar
Michael Hanselmann committed
815
816
817
818
819
                queue.UpdateJobUnlocked(job)
            finally:
              queue.release()
            raise

820
      except CancelJob:
821
        queue.acquire(shared=1)
822
        try:
823
824
          job.MarkUnfinishedOps(constants.OP_STATUS_CANCELED,
                                "Job canceled by request")
825
826
          job.end_timestamp = TimeStampNow()
          queue.UpdateJobUnlocked(job)
827
828
        finally:
          queue.release()
Michael Hanselmann's avatar
Michael Hanselmann committed
829
830
831
832
      except errors.GenericError, err:
        logging.exception("Ganeti exception")
      except:
        logging.exception("Unhandled exception")
Michael Hanselmann's avatar
Michael Hanselmann committed
833
    finally:
834
835
      status = job.CalcStatus()
      logging.info("Finished job %s, status = %s", job.id, status)
Michael Hanselmann's avatar
Michael Hanselmann committed
836
837
838


class _JobQueueWorkerPool(workerpool.WorkerPool):
839
840
841
  """Simple class implementing a job-processing workerpool.

  """
842
  def __init__(self, queue):
843
844
    super(_JobQueueWorkerPool, self).__init__("JobQueue",
                                              JOBQUEUE_THREADS,
Michael Hanselmann's avatar
Michael Hanselmann committed
845
                                              _JobQueueWorker)
846
    self.queue = queue
Michael Hanselmann's avatar
Michael Hanselmann committed
847
848


Iustin Pop's avatar
Iustin Pop committed
849
850
def _RequireOpenQueue(fn):
  """Decorator for "public" functions.
851

Iustin Pop's avatar
Iustin Pop committed
852
853
854
855
  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
856
  a '_queue_filelock' argument.
857

858
  @warning: Use this decorator only after locking.ssynchronized
859

Iustin Pop's avatar
Iustin Pop committed
860
  Example::
861
    @locking.ssynchronized(_LOCK)
Iustin Pop's avatar
Iustin Pop committed
862
863
864
    @_RequireOpenQueue
    def Example(self):
      pass
865

Iustin Pop's avatar
Iustin Pop committed
866
867
  """
  def wrapper(self, *args, **kwargs):
Iustin Pop's avatar
Iustin Pop committed
868
    # pylint: disable-msg=W0212
869
    assert self._queue_filelock is not None, "Queue should be open"
Iustin Pop's avatar
Iustin Pop committed
870
871
    return fn(self, *args, **kwargs)
  return wrapper
872
873


Iustin Pop's avatar
Iustin Pop committed
874
875
class JobQueue(object):
  """Queue used to manage the jobs.
876

Iustin Pop's avatar
Iustin Pop committed
877
878
879
880
  @cvar _RE_JOB_FILE: regex matching the valid job file names

  """
  _RE_JOB_FILE = re.compile(r"^job-(%s)$" % constants.JOB_ID_TEMPLATE)
881

Michael Hanselmann's avatar
Michael Hanselmann committed
882
  def __init__(self, context):
883
884
885
886
887
888
889
890
891
892
893
894
    """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

    """
895
    self.context = context
896
    self._memcache = weakref.WeakValueDictionary()
897
    self._my_hostname = netutils.Hostname.GetSysName()
898

899
900
901
902
903
    # 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.
904
    self._lock = locking.SharedLock("JobQueue")
905
906
907

    self.acquire = self._lock.acquire
    self.release = self._lock.release
Michael Hanselmann's avatar
Michael Hanselmann committed
908

909
910
911
    # 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)
912

913
914
915
916
    # 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")
917

918
    # Get initial list of nodes
919
    self._nodes = dict((n.name, n.primary_ip)
920
921
                       for n in self.context.cfg.GetAllNodesInfo().values()
                       if n.master_candidate)
922
923

    # Remove master node
924
    self._nodes.pop(self._my_hostname, None)
925
926
927

    # TODO: Check consistency across nodes

928
929
930
931
    self._queue_size = 0
    self._UpdateQueueSizeUnlocked()
    self._drained = self._IsQueueMarkedDrain()

Michael Hanselmann's avatar
Michael Hanselmann committed
932
    # Setup worker pool
933
    self._wpool = _JobQueueWorkerPool(self)
Michael Hanselmann's avatar
Michael Hanselmann committed
934
    try:
935
936
937
938
      self._InspectQueue()
    except:
      self._wpool.TerminateWorkers()
      raise
939

940
941
942
943
944
945
946
  @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.
947

948
949
950
951
952
953
954
955
956
957
958
959
    """
    logging.info("Inspecting job queue")

    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)
960
        lastinfo = time.time()
961

962
      job = self._LoadJobUnlocked(job_id)
Michael Hanselmann's avatar
Michael Hanselmann committed
963

964
965
966
      # a failure in loading the job can cause 'None' to be returned
      if job is None:
        continue
Michael Hanselmann's avatar
Michael Hanselmann committed
967

968
      status = job.CalcStatus()
969

970
      if status in (constants.JOB_STATUS_QUEUED, ):
971
972
973
        self._wpool.AddTask((job, ))

      elif status in (constants.JOB_STATUS_RUNNING,
974
                      constants.JOB_STATUS_WAITLOCK,
975
976
977
978
979
980
981
                      constants.JOB_STATUS_CANCELING):
        logging.warning("Unfinished job %s found: %s", job.id, job)
        job.MarkUnfinishedOps(constants.OP_STATUS_ERROR,
                              "Unclean master daemon shutdown")
        self.UpdateJobUnlocked(job)

    logging.info("Job queue inspection finished")
Michael Hanselmann's avatar
Michael Hanselmann committed
982

983
  @locking.ssynchronized(_LOCK)
984
  @_RequireOpenQueue
985
986
987
988
989
990
991
992
  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
993
    assert node_name != self._my_hostname
994

995
    # Clean queue directory on added node
996
    result = rpc.RpcRunner.call_jobqueue_purge(node_name)
997
    msg = result.fail_msg
998
999
1000
    if msg:
      logging.warning("Cannot cleanup queue directory on node %s: %s",
                      node_name, msg)
1001

1002
1003
1004
1005
1006
1007
    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

1008
1009
    # Upload the whole queue excluding archived jobs
    files = [self._GetJobPath(job_id) for job_id in self._GetJobIDsUnlocked()]
1010

1011
1012
1013
1014
    # Upload current serial file
    files.append(constants.JOB_QUEUE_SERIAL_FILE)

    for file_name in files:
1015
      # Read file content
1016
      content = utils.ReadFile(file_name)
1017

1018
1019
1020
      result = rpc.RpcRunner.call_jobqueue_update([node_name],
                                                  [node.primary_ip],
                                                  file_name, content)
1021
      msg = result[node_name].fail_msg
1022
1023
1024
      if msg:
        logging.error("Failed to upload file %s to node %s: %s",
                      file_name, node_name, msg)
1025

1026
    self._nodes[node_name] = node.primary_ip
1027

1028
  @locking.ssynchronized(_LOCK)
1029
1030
  @_RequireOpenQueue
  def RemoveNode(self, node_name):
1031
1032
1033
1034
1035
1036
    """Callback called when removing nodes from the cluster.

    @type node_name: str
    @param node_name: the name of the node to remove

    """
1037
    self._nodes.pop(node_name, None)
1038

1039
1040
  @staticmethod
  def _CheckRpcResult(result, nodes, failmsg):
1041
1042
1043
1044
    """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
Michael Hanselmann's avatar
Michael Hanselmann committed
1045
    log the case when more than half of the nodes fails.
1046
1047
1048
1049
1050
1051
1052
1053

    @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

    """
1054
1055
1056
1057
    failed = []
    success = []

    for node in nodes:
1058
      msg = result[node].fail_msg
1059
      if msg:
1060
        failed.append(node)
1061
1062
        logging.error("RPC call %s (%s) failed on node %s: %s",
                      result[node].call, failmsg, node, msg)
1063
1064
      else:
        success.append(node)
1065
1066
1067
1068
1069
1070

    # +1 for the master node
    if (len(success) + 1) < len(failed):
      # TODO: Handle failing nodes
      logging.error("More than half of the nodes failed")

1071
1072
1073
  def _GetNodeIp(self):
    """Helper for returning the node name/ip list.

1074
1075
1076
1077
    @rtype: (list, list)
    @return: a tuple of two lists, the first one with the node
        names and the second one with the node addresses

1078
    """
1079
    # TODO: Change to "tuple(map(list, zip(*self._nodes.items())))"?
1080
1081
1082
1083
    name_list = self._nodes.keys()
    addr_list = [self._nodes[name] for name in name_list]
    return name_list, addr_list

1084
  def _UpdateJobQueueFile(self, file_name, data, replicate):
1085
1086
    """Writes a file locally and then replicates it to all nodes.

1087
1088
1089
1090
1091
1092
1093
    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
1094
1095
    @type replicate: boolean
    @param replicate: whether to spread the changes to the remote nodes
1096

1097
    """
1098
1099
1100
    getents = runtime.GetEnts()
    utils.WriteFile(file_name, data=data, uid=getents.masterd_uid,
                    gid=getents.masterd_gid)
1101

1102
1103
1104
1105
    if replicate:
      names, addrs = self._GetNodeIp()
      result = rpc.RpcRunner.call_jobqueue_update(names, addrs, file_name, data)
      self._CheckRpcResult(result, self._nodes, "Updating %s" % file_name)
1106

1107
  def _RenameFilesUnlocked(self, rename):
1108
1109
1110
1111
1112
    """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.

1113
1114
    @type rename: list of (old, new)
    @param rename: List containing tuples mapping old to new names
1115
1116

    """
1117
    # Rename them locally
1118
1119
    for old, new in rename:
      utils.RenameFile(old, new, mkdir=True)
1120

1121
1122
1123
1124
    # ... and on all nodes
    names, addrs = self._GetNodeIp()
    result = rpc.RpcRunner.call_jobqueue_rename(names, addrs, rename)
    self._CheckRpcResult(result, self._nodes, "Renaming files (%r)" % rename)
1125

1126
1127
  @staticmethod
  def _FormatJobID(job_id):
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
    """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

    """
Michael Hanselmann's avatar
Michael Hanselmann committed
1140
1141
1142
1143
1144
1145
1146
    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)

1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
  @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)

Iustin Pop's avatar
Iustin Pop committed
1159
  def _NewSerialsUnlocked(self, count):
1160
1161
1162
1163
    """Generates a new job identifier.

    Job identifiers are unique during the lifetime of a cluster.

Iustin Pop's avatar
Iustin Pop committed
1164
1165
    @type count: integer
    @param count: how many serials to return
1166
1167
    @rtype: str
    @return: a string representing the job identifier.
1168
1169

    """
Iustin Pop's avatar
Iustin Pop committed
1170
    assert count > 0
1171
    # New number
Iustin Pop's avatar
Iustin Pop committed
1172
    serial = self._last_serial + count
1173
1174

    # Write to file