jqueue.py 49 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 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",
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

  @classmethod
  def Restore(cls, state):
118
119
120
121
122
123
124
125
    """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
126
127
128
129
130
    obj = _QueuedOpCode.__new__(cls)
    obj.input = opcodes.OpCode.LoadOpCode(state["input"])
    obj.status = state["status"]
    obj.result = state["result"]
    obj.log = state["log"]
131
    obj.start_timestamp = state.get("start_timestamp", None)
Iustin Pop's avatar
Iustin Pop committed
132
    obj.exec_timestamp = state.get("exec_timestamp", None)
133
    obj.end_timestamp = state.get("end_timestamp", None)
134
135
136
    return obj

  def Serialize(self):
137
138
139
140
141
142
    """Serializes this _QueuedOpCode.

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

    """
143
144
145
146
147
    return {
      "input": self.input.__getstate__(),
      "status": self.status,
      "result": self.result,
      "log": self.log,
148
      "start_timestamp": self.start_timestamp,
Iustin Pop's avatar
Iustin Pop committed
149
      "exec_timestamp": self.exec_timestamp,
150
      "end_timestamp": self.end_timestamp,
151
      }
152

Michael Hanselmann's avatar
Michael Hanselmann committed
153
154
155
156

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

157
158
159
160
161
162
163
164
165
166
167
168
169
  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
170
171

  """
Iustin Pop's avatar
Iustin Pop committed
172
  # pylint: disable-msg=W0212
173
  __slots__ = ["queue", "id", "ops", "log_serial",
174
175
176
               "received_timestamp", "start_timestamp", "end_timestamp",
               "__weakref__"]

Michael Hanselmann's avatar
Michael Hanselmann committed
177
  def __init__(self, queue, job_id, ops):
178
179
180
181
182
183
184
185
186
187
188
    """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
189
    if not ops:
Guido Trotter's avatar
Guido Trotter committed
190
      raise errors.GenericError("A job needs at least one opcode")
Michael Hanselmann's avatar
Michael Hanselmann committed
191

Michael Hanselmann's avatar
Michael Hanselmann committed
192
    self.queue = queue
193
    self.id = job_id
Michael Hanselmann's avatar
Michael Hanselmann committed
194
    self.ops = [_QueuedOpCode(op) for op in ops]
195
    self.log_serial = 0
196
197
198
    self.received_timestamp = TimeStampNow()
    self.start_timestamp = None
    self.end_timestamp = None
199

200
201
202
203
204
205
206
  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))

207
  @classmethod
Michael Hanselmann's avatar
Michael Hanselmann committed
208
  def Restore(cls, queue, state):
209
210
211
212
213
214
215
216
217
218
    """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
219
220
221
    obj = _QueuedJob.__new__(cls)
    obj.queue = queue
    obj.id = state["id"]
222
223
224
    obj.received_timestamp = state.get("received_timestamp", None)
    obj.start_timestamp = state.get("start_timestamp", None)
    obj.end_timestamp = state.get("end_timestamp", None)
225
226
227
228
229
230
231
232
233

    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)

234
235
236
    return obj

  def Serialize(self):
237
238
239
240
241
242
    """Serialize the _JobQueue instance.

    @rtype: dict
    @return: the serialized state

    """
243
244
    return {
      "id": self.id,
Michael Hanselmann's avatar
Michael Hanselmann committed
245
      "ops": [op.Serialize() for op in self.ops],
246
247
248
      "start_timestamp": self.start_timestamp,
      "end_timestamp": self.end_timestamp,
      "received_timestamp": self.received_timestamp,
249
250
      }

Michael Hanselmann's avatar
Michael Hanselmann committed
251
  def CalcStatus(self):
252
253
254
255
256
257
258
259
260
261
    """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
262
          - canceling
263
264
265
266
267
268
269
270
271
272
          - 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
273
274
275
    status = constants.JOB_STATUS_QUEUED

    all_success = True
Michael Hanselmann's avatar
Michael Hanselmann committed
276
277
    for op in self.ops:
      if op.status == constants.OP_STATUS_SUCCESS:
Michael Hanselmann's avatar
Michael Hanselmann committed
278
279
280
281
        continue

      all_success = False

Michael Hanselmann's avatar
Michael Hanselmann committed
282
      if op.status == constants.OP_STATUS_QUEUED:
Michael Hanselmann's avatar
Michael Hanselmann committed
283
        pass
Iustin Pop's avatar
Iustin Pop committed
284
285
      elif op.status == constants.OP_STATUS_WAITLOCK:
        status = constants.JOB_STATUS_WAITLOCK
Michael Hanselmann's avatar
Michael Hanselmann committed
286
      elif op.status == constants.OP_STATUS_RUNNING:
Michael Hanselmann's avatar
Michael Hanselmann committed
287
        status = constants.JOB_STATUS_RUNNING
288
289
290
      elif op.status == constants.OP_STATUS_CANCELING:
        status = constants.JOB_STATUS_CANCELING
        break
Michael Hanselmann's avatar
Michael Hanselmann committed
291
      elif op.status == constants.OP_STATUS_ERROR:
292
293
294
        status = constants.JOB_STATUS_ERROR
        # The whole job fails if one opcode failed
        break
Michael Hanselmann's avatar
Michael Hanselmann committed
295
      elif op.status == constants.OP_STATUS_CANCELED:
296
297
        status = constants.OP_STATUS_CANCELED
        break
Michael Hanselmann's avatar
Michael Hanselmann committed
298
299
300
301
302
303

    if all_success:
      status = constants.JOB_STATUS_SUCCESS

    return status

304
  def GetLogEntries(self, newer_than):
305
306
307
    """Selectively returns the log entries.

    @type newer_than: None or int
Michael Hanselmann's avatar
Michael Hanselmann committed
308
    @param newer_than: if this is None, return all log entries,
309
310
311
312
313
314
        otherwise return only the log entries with serial higher
        than this value
    @rtype: list
    @return: the list of the log entries selected

    """
315
316
317
318
319
320
321
    if newer_than is None:
      serial = -1
    else:
      serial = newer_than

    entries = []
    for op in self.ops:
322
      entries.extend(filter(lambda entry: entry[0] > serial, op.log))
323
324
325

    return entries

326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
  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

369
370
371
372
373
374
375
376
377
378
379
  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

    """
380
381
382
383
384
385
386
387
    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
388

389

390
class _OpExecCallbacks(mcpu.OpExecCbBase):
391
392
  def __init__(self, queue, job, op):
    """Initializes this class.
393

394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
    @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

410
411
412
413
414
415
416
417
418
  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()

419
  @locking.ssynchronized(_QUEUE, shared=1)
420
  def NotifyStart(self):
Iustin Pop's avatar
Iustin Pop committed
421
422
    """Mark the opcode as running, not lock-waiting.

423
424
425
426
    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
427
428

    """
429
    assert self._op in self._job.ops
430
431
    assert self._op.status in (constants.OP_STATUS_WAITLOCK,
                               constants.OP_STATUS_CANCELING)
432

433
    # Cancel here if we were asked to
434
    self._CheckCancel()
435

436
    logging.debug("Opcode is now running")
437

438
439
440
441
442
    self._op.status = constants.OP_STATUS_RUNNING
    self._op.exec_timestamp = TimeStampNow()

    # And finally replicate the job status
    self._queue.UpdateJobUnlocked(self._job)
443

444
  @locking.ssynchronized(_QUEUE, shared=1)
445
446
447
448
449
450
451
452
  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)

453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
  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())
468
    self._AppendFeedback(timestamp, log_type, log_msg)
469

470
471
472
473
474
475
  def ReportLocks(self, msg):
    """Write locking information to the job.

    Called whenever the LU processor is waiting for a lock or has acquired one.

    """
476
477
478
479
480
481
    assert self._op.status in (constants.OP_STATUS_WAITLOCK,
                               constants.OP_STATUS_CANCELING)

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

482

483
484
485
class _JobChangesChecker(object):
  def __init__(self, fields, prev_job_info, prev_log_serial):
    """Initializes this class.
Guido Trotter's avatar
Guido Trotter committed
486

487
488
489
490
491
492
    @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
493

494
495
496
497
    """
    self._fields = fields
    self._prev_job_info = prev_job_info
    self._prev_log_serial = prev_log_serial
Guido Trotter's avatar
Guido Trotter committed
498

499
500
  def __call__(self, job):
    """Checks whether job has changed.
Guido Trotter's avatar
Guido Trotter committed
501

502
503
    @type job: L{_QueuedJob}
    @param job: Job object
Guido Trotter's avatar
Guido Trotter committed
504
505

    """
506
507
508
    status = job.CalcStatus()
    job_info = job.GetInfo(self._fields)
    log_entries = job.GetLogEntries(self._prev_log_serial)
Guido Trotter's avatar
Guido Trotter committed
509
510
511
512
513
514
515
516

    # 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.
517
518
519
520
    # 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
521
522
523

    # Don't even try to wait if the job is no longer running, there will be
    # no changes.
524
525
526
527
528
529
530
    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
531

532
533
534
535
536
537
538
539
540
541
    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
542

543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
    """
    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
560
    if not notifier_enabled:
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
      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
595

596
597
  def Wait(self, timeout):
    """Waits for a job to change.
Guido Trotter's avatar
Guido Trotter committed
598

599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
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
    @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
660
    try:
661
662
663
664
665
666
667
668
669
      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
670
671
672
673
674
675
    except (errors.InotifyError, errors.JobLost):
      return None
    except utils.RetryTimeout:
      return constants.JOB_NOTCHANGED


676
677
678
679
680
681
682
683
684
685
686
687
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)


688
689
690
691
class _JobQueueWorker(workerpool.BaseWorker):
  """The actual job workers.

  """
Iustin Pop's avatar
Iustin Pop committed
692
  def RunTask(self, job): # pylint: disable-msg=W0221
Michael Hanselmann's avatar
Michael Hanselmann committed
693
694
    """Job executor.

695
696
    This functions processes a job. It is closely tied to the _QueuedJob and
    _QueuedOpCode classes.
Michael Hanselmann's avatar
Michael Hanselmann committed
697

698
699
700
    @type job: L{_QueuedJob}
    @param job: the job to be processed

Michael Hanselmann's avatar
Michael Hanselmann committed
701
    """
702
703
    self.SetTaskName("Job%s" % job.id)

704
    logging.info("Processing job %s", job.id)
705
    proc = mcpu.Processor(self.pool.queue.context, job.id)
706
    queue = job.queue
Michael Hanselmann's avatar
Michael Hanselmann committed
707
    try:
Michael Hanselmann's avatar
Michael Hanselmann committed
708
709
710
      try:
        count = len(job.ops)
        for idx, op in enumerate(job.ops):
711
          op_summary = op.input.Summary()
712
713
714
715
716
717
718
719
720
          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
721
          try:
722
723
            logging.info("Op %s/%s: Starting opcode %s", idx + 1, count,
                         op_summary)
Michael Hanselmann's avatar
Michael Hanselmann committed
724

725
            queue.acquire(shared=1)
Michael Hanselmann's avatar
Michael Hanselmann committed
726
            try:
727
              if op.status == constants.OP_STATUS_CANCELED:
728
                logging.debug("Canceling opcode")
729
                raise CancelJob()
730
              assert op.status == constants.OP_STATUS_QUEUED
731
732
              logging.debug("Opcode %s/%s waiting for locks",
                            idx + 1, count)
Iustin Pop's avatar
Iustin Pop committed
733
              op.status = constants.OP_STATUS_WAITLOCK
Michael Hanselmann's avatar
Michael Hanselmann committed
734
              op.result = None
735
              op.start_timestamp = TimeStampNow()
736
737
              if idx == 0: # first opcode
                job.start_timestamp = op.start_timestamp
Michael Hanselmann's avatar
Michael Hanselmann committed
738
739
              queue.UpdateJobUnlocked(job)

Iustin Pop's avatar
Iustin Pop committed
740
              input_opcode = op.input
Michael Hanselmann's avatar
Michael Hanselmann committed
741
742
743
            finally:
              queue.release()

744
745
            # Make sure not to hold queue lock while calling ExecOpCode
            result = proc.ExecOpCode(input_opcode,
746
                                     _OpExecCallbacks(queue, job, op))
Michael Hanselmann's avatar
Michael Hanselmann committed
747

748
            queue.acquire(shared=1)
Michael Hanselmann's avatar
Michael Hanselmann committed
749
            try:
750
              logging.debug("Opcode %s/%s succeeded", idx + 1, count)
Michael Hanselmann's avatar
Michael Hanselmann committed
751
752
              op.status = constants.OP_STATUS_SUCCESS
              op.result = result
753
              op.end_timestamp = TimeStampNow()
754
755
              if idx == count - 1:
                job.end_timestamp = TimeStampNow()
756
757
758
759
760

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

Michael Hanselmann's avatar
Michael Hanselmann committed
761
762
763
764
              queue.UpdateJobUnlocked(job)
            finally:
              queue.release()

765
766
            logging.info("Op %s/%s: Successfully finished opcode %s",
                         idx + 1, count, op_summary)
767
768
769
          except CancelJob:
            # Will be handled further up
            raise
Michael Hanselmann's avatar
Michael Hanselmann committed
770
          except Exception, err:
771
            queue.acquire(shared=1)
Michael Hanselmann's avatar
Michael Hanselmann committed
772
773
            try:
              try:
774
                logging.debug("Opcode %s/%s failed", idx + 1, count)
Michael Hanselmann's avatar
Michael Hanselmann committed
775
                op.status = constants.OP_STATUS_ERROR
776
                op.result = _EncodeOpError(err)
777
                op.end_timestamp = TimeStampNow()
778
779
                logging.info("Op %s/%s: Error in opcode %s: %s",
                             idx + 1, count, op_summary, err)
780
781
782

                to_encode = errors.OpExecError("Preceding opcode failed")
                job.MarkUnfinishedOps(constants.OP_STATUS_ERROR,
783
                                      _EncodeOpError(to_encode))
784
785
786
787
788
789
790

                # 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
791
              finally:
792
                job.end_timestamp = TimeStampNow()
Michael Hanselmann's avatar
Michael Hanselmann committed
793
794
795
796
797
                queue.UpdateJobUnlocked(job)
            finally:
              queue.release()
            raise

798
      except CancelJob:
799
        queue.acquire(shared=1)
800
        try:
801
802
          job.MarkUnfinishedOps(constants.OP_STATUS_CANCELED,
                                "Job canceled by request")
803
804
          job.end_timestamp = TimeStampNow()
          queue.UpdateJobUnlocked(job)
805
806
        finally:
          queue.release()
Michael Hanselmann's avatar
Michael Hanselmann committed
807
808
809
810
      except errors.GenericError, err:
        logging.exception("Ganeti exception")
      except:
        logging.exception("Unhandled exception")
Michael Hanselmann's avatar
Michael Hanselmann committed
811
    finally:
812
813
      status = job.CalcStatus()
      logging.info("Finished job %s, status = %s", job.id, status)
Michael Hanselmann's avatar
Michael Hanselmann committed
814
815
816


class _JobQueueWorkerPool(workerpool.WorkerPool):
817
818
819
  """Simple class implementing a job-processing workerpool.

  """
820
  def __init__(self, queue):
821
822
    super(_JobQueueWorkerPool, self).__init__("JobQueue",
                                              JOBQUEUE_THREADS,
Michael Hanselmann's avatar
Michael Hanselmann committed
823
                                              _JobQueueWorker)
824
    self.queue = queue
Michael Hanselmann's avatar
Michael Hanselmann committed
825
826


Iustin Pop's avatar
Iustin Pop committed
827
828
def _RequireOpenQueue(fn):
  """Decorator for "public" functions.
829

Iustin Pop's avatar
Iustin Pop committed
830
831
832
833
  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
834
  a '_queue_filelock' argument.
835

836
  @warning: Use this decorator only after locking.ssynchronized
837

Iustin Pop's avatar
Iustin Pop committed
838
  Example::
839
    @locking.ssynchronized(_LOCK)
Iustin Pop's avatar
Iustin Pop committed
840
841
842
    @_RequireOpenQueue
    def Example(self):
      pass
843

Iustin Pop's avatar
Iustin Pop committed
844
845
  """
  def wrapper(self, *args, **kwargs):
Iustin Pop's avatar
Iustin Pop committed
846
    # pylint: disable-msg=W0212
847
    assert self._queue_filelock is not None, "Queue should be open"
Iustin Pop's avatar
Iustin Pop committed
848
849
    return fn(self, *args, **kwargs)
  return wrapper
850
851


Iustin Pop's avatar
Iustin Pop committed
852
853
class JobQueue(object):
  """Queue used to manage the jobs.
854

Iustin Pop's avatar
Iustin Pop committed
855
856
857
858
  @cvar _RE_JOB_FILE: regex matching the valid job file names

  """
  _RE_JOB_FILE = re.compile(r"^job-(%s)$" % constants.JOB_ID_TEMPLATE)
859

Michael Hanselmann's avatar
Michael Hanselmann committed
860
  def __init__(self, context):
861
862
863
864
865
866
867
868
869
870
871
872
    """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

    """
873
    self.context = context
874
    self._memcache = weakref.WeakValueDictionary()
875
    self._my_hostname = netutils.HostInfo().name
876

877
878
879
880
881
    # 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.
882
    self._lock = locking.SharedLock("JobQueue")
883
884
885

    self.acquire = self._lock.acquire
    self.release = self._lock.release
Michael Hanselmann's avatar
Michael Hanselmann committed
886

887
888
889
    # 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)
890

891
892
893
894
    # 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")
895

896
    # Get initial list of nodes
897
    self._nodes = dict((n.name, n.primary_ip)
898
899
                       for n in self.context.cfg.GetAllNodesInfo().values()
                       if n.master_candidate)
900
901

    # Remove master node
902
    self._nodes.pop(self._my_hostname, None)
903
904
905

    # TODO: Check consistency across nodes

906
907
908
909
    self._queue_size = 0
    self._UpdateQueueSizeUnlocked()
    self._drained = self._IsQueueMarkedDrain()

Michael Hanselmann's avatar
Michael Hanselmann committed
910
    # Setup worker pool
911
    self._wpool = _JobQueueWorkerPool(self)
Michael Hanselmann's avatar
Michael Hanselmann committed
912
    try:
913
914
915
916
      self._InspectQueue()
    except:
      self._wpool.TerminateWorkers()
      raise
917

918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
  @locking.ssynchronized(_LOCK)
  @_RequireOpenQueue
  def _InspectQueue(self):
    """Loads the whole job queue and resumes unfinished jobs.

    This function needs the lock here because WorkerPool.AddTask() may start a
    job while we're still doing our work.

    """
    logging.info("Inspecting job queue")

    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)
938
        lastinfo = time.time()
939

940
      job = self._LoadJobUnlocked(job_id)
Michael Hanselmann's avatar
Michael Hanselmann committed
941

942
943
944
      # a failure in loading the job can cause 'None' to be returned
      if job is None:
        continue
Michael Hanselmann's avatar
Michael Hanselmann committed
945

946
      status = job.CalcStatus()
947

948
      if status in (constants.JOB_STATUS_QUEUED, ):
949
950
951
        self._wpool.AddTask((job, ))

      elif status in (constants.JOB_STATUS_RUNNING,
952
                      constants.JOB_STATUS_WAITLOCK,
953
954
955
956
957
958
959
                      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
960

961
  @locking.ssynchronized(_LOCK)
962
  @_RequireOpenQueue
963
964
965
966
967
968
969
970
  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
971
    assert node_name != self._my_hostname
972

973
    # Clean queue directory on added node
974
    result = rpc.RpcRunner.call_jobqueue_purge(node_name)
975
    msg = result.fail_msg
976
977
978
    if msg:
      logging.warning("Cannot cleanup queue directory on node %s: %s",
                      node_name, msg)
979

980
981
982
983
984
985
    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

986
987
    # Upload the whole queue excluding archived jobs
    files = [self._GetJobPath(job_id) for job_id in self._GetJobIDsUnlocked()]
988

989
990
991
992
    # Upload current serial file
    files.append(constants.JOB_QUEUE_SERIAL_FILE)

    for file_name in files:
993
      # Read file content
994
      content = utils.ReadFile(file_name)
995

996
997
998
      result = rpc.RpcRunner.call_jobqueue_update([node_name],
                                                  [node.primary_ip],
                                                  file_name, content)
999
      msg = result[node_name].fail_msg
1000
1001
1002
      if msg:
        logging.error("Failed to upload file %s to node %s: %s",
                      file_name, node_name, msg)
1003

1004
    self._nodes[node_name] = node.primary_ip
1005

1006
  @locking.ssynchronized(_LOCK)
1007
1008
  @_RequireOpenQueue
  def RemoveNode(self, node_name):
1009
1010
1011
1012
1013
1014
    """Callback called when removing nodes from the cluster.

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

    """
1015
    self._nodes.pop(node_name, None)
1016

1017
1018
  @staticmethod
  def _CheckRpcResult(result, nodes, failmsg):
1019
1020
1021
1022
    """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
1023
    log the case when more than half of the nodes fails.
1024
1025
1026
1027
1028
1029
1030
1031

    @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

    """
1032
1033
1034
1035
    failed = []
    success = []

    for node in nodes:
1036
      msg = result[node].fail_msg
1037
      if msg:
1038
        failed.append(node)
1039
1040
        logging.error("RPC call %s (%s) failed on node %s: %s",
                      result[node].call, failmsg, node, msg)
1041
1042
      else:
        success.append(node)
1043
1044
1045
1046
1047
1048

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

1049
1050
1051
  def _GetNodeIp(self):
    """Helper for returning the node name/ip list.

1052
1053
1054
1055
    @rtype: (list, list)
    @return: a tuple of two lists, the first one with the node
        names and the second one with the node addresses

1056
    """
1057
    # TODO: Change to "tuple(map(list, zip(*self._nodes.items())))"?
1058
1059
1060
1061
    name_list = self._nodes.keys()
    addr_list = [self._nodes[name] for name in name_list]
    return name_list, addr_list

1062
  def _UpdateJobQueueFile(self, file_name, data, replicate):
1063
1064
    """Writes a file locally and then replicates it to all nodes.

1065
1066
1067
1068
1069
1070
1071
    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
1072
1073
    @type replicate: boolean
    @param replicate: whether to spread the changes to the remote nodes
1074

1075
1076
1077
    """
    utils.WriteFile(file_name, data=data)

1078
1079
1080
1081
    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)
1082

1083
  def _RenameFilesUnlocked(self, rename):
1084
1085
1086
1087
1088
    """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.

1089
1090
    @type rename: list of (old, new)
    @param rename: List containing tuples mapping old to new names
1091
1092

    """
1093
    # Rename them locally
1094
1095
    for old, new in rename:
      utils.RenameFile(old, new, mkdir=True)
1096

1097
1098
1099
1100
    # ... 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)
1101

1102
1103
  @staticmethod
  def _FormatJobID(job_id):
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
    """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
1116
1117
1118
1119
1120
1121
1122
    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)

1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
  @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
1135
  def _NewSerialsUnlocked(self, count):
1136
1137
1138
1139
    """Generates a new job identifier.

    Job identifiers are unique during the lifetime of a cluster.

Iustin Pop's avatar
Iustin Pop committed
1140
1141
    @type count: integer
    @param count: how many serials to return
1142
1143
    @rtype: str
    @return: a string representing the job identifier.
1144
1145

    """
Iustin Pop's avatar
Iustin Pop committed
1146
    assert count > 0
1147
    # New number
Iustin Pop's avatar
Iustin Pop committed
1148
    serial = self._last_serial + count
1149
1150

    # Write to file
1151
1152
    self._UpdateJobQueueFile(constants.JOB_QUEUE_SERIAL_FILE,
                             "%s\n" % serial, True)
1153

Iustin Pop's avatar
Iustin Pop committed
1154
1155
    result = [self._FormatJobID(v)
              for v in range(self._last_serial, serial + 1)]
1156
1157
1158
    # Keep it only if we were able to write the file
    self._last_serial = serial

Iustin Pop's avatar
Iustin Pop committed
1159
    return result
1160

Michael Hanselmann's avatar
Michael Hanselmann committed
1161
1162
  @staticmethod
  def _GetJobPath(job_id):
1163
1164
1165
1166
1167
1168
1169
1170
    """Returns the job file for a given job id.

    @type job_id: str
    @param job_id: the job identifier
    @rtype: str
    @return: the path to the job file

    """
1171
    return utils.PathJoin(constants.QUEUE_DIR, "job-%s" % job_id)
1172

1173
1174
  @classmethod
  def _GetArchivedJobPath(cls, job_id):
1175
1176
1177
1178
1179
1180