4 # Copyright (C) 2006, 2007, 2011 Google Inc.
6 # This program is free software; you can redistribute it and/or modify
7 # it under the terms of the GNU General Public License as published by
8 # the Free Software Foundation; either version 2 of the License, or
9 # (at your option) any later version.
11 # This program is distributed in the hope that it will be useful, but
12 # WITHOUT ANY WARRANTY; without even the implied warranty of
13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 # General Public License for more details.
16 # You should have received a copy of the GNU General Public License
17 # along with this program; if not, write to the Free Software
18 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
22 """Module implementing the logic behind the cluster operations
24 This module implements the logic for doing operations in the cluster. There
25 are two kinds of classes defined:
26 - logical units, which know how to deal with their specific opcode only
27 - the processor, which dispatches the opcodes to their logical units
36 from ganeti import opcodes
37 from ganeti import constants
38 from ganeti import errors
39 from ganeti import cmdlib
40 from ganeti import locking
41 from ganeti import utils
42 from ganeti import compat
49 class LockAcquireTimeout(Exception):
50 """Exception to report timeouts on acquiring locks.
55 def _CalculateLockAttemptTimeouts():
56 """Calculate timeouts for lock attempts.
59 result = [constants.LOCK_ATTEMPTS_MINWAIT]
60 running_sum = result[0]
62 # Wait for a total of at least LOCK_ATTEMPTS_TIMEOUT before doing a
64 while running_sum < constants.LOCK_ATTEMPTS_TIMEOUT:
65 timeout = (result[-1] * 1.05) ** 1.25
67 # Cap max timeout. This gives other jobs a chance to run even if
68 # we're still trying to get our locks, before finally moving to a
70 timeout = min(timeout, constants.LOCK_ATTEMPTS_MAXWAIT)
71 # And also cap the lower boundary for safety
72 timeout = max(timeout, constants.LOCK_ATTEMPTS_MINWAIT)
74 result.append(timeout)
75 running_sum += timeout
80 class LockAttemptTimeoutStrategy(object):
81 """Class with lock acquire timeout strategy.
90 _TIMEOUT_PER_ATTEMPT = _CalculateLockAttemptTimeouts()
92 def __init__(self, _time_fn=time.time, _random_fn=random.random):
93 """Initializes this class.
95 @param _time_fn: Time function for unittests
96 @param _random_fn: Random number generator for unittests
101 self._timeouts = iter(self._TIMEOUT_PER_ATTEMPT)
102 self._time_fn = _time_fn
103 self._random_fn = _random_fn
105 def NextAttempt(self):
106 """Returns the timeout for the next attempt.
110 timeout = self._timeouts.next()
111 except StopIteration:
112 # No more timeouts, do blocking acquire
115 if timeout is not None:
116 # Add a small variation (-/+ 5%) to timeout. This helps in situations
117 # where two or more jobs are fighting for the same lock(s).
118 variation_range = timeout * 0.1
119 timeout += ((self._random_fn() * variation_range) -
120 (variation_range * 0.5))
125 class OpExecCbBase: # pylint: disable=W0232
126 """Base class for OpCode execution callbacks.
129 def NotifyStart(self):
130 """Called when we are about to execute the LU.
132 This function is called when we're about to start the lu's Exec() method,
133 that is, after we have acquired all locks.
137 def Feedback(self, *args):
138 """Sends feedback from the LU code to the end-user.
142 def CheckCancel(self):
143 """Check whether job has been cancelled.
147 def SubmitManyJobs(self, jobs):
148 """Submits jobs for processing.
150 See L{jqueue.JobQueue.SubmitManyJobs}.
153 raise NotImplementedError
156 def _LUNameForOpName(opname):
157 """Computes the LU name for a given OpCode name.
160 assert opname.startswith(_OP_PREFIX), \
161 "Invalid OpCode name, doesn't start with %s: %s" % (_OP_PREFIX, opname)
163 return _LU_PREFIX + opname[len(_OP_PREFIX):]
166 def _ComputeDispatchTable():
167 """Computes the opcode-to-lu dispatch table.
170 return dict((op, getattr(cmdlib, _LUNameForOpName(op.__name__)))
171 for op in opcodes.OP_MAPPING.values()
175 def _SetBaseOpParams(src, defcomment, dst):
176 """Copies basic opcode parameters.
178 @type src: L{opcodes.OpCode}
179 @param src: Source opcode
180 @type defcomment: string
181 @param defcomment: Comment to specify if not already given
182 @type dst: L{opcodes.OpCode}
183 @param dst: Destination opcode
186 if hasattr(src, "debug_level"):
187 dst.debug_level = src.debug_level
189 if (getattr(dst, "priority", None) is None and
190 hasattr(src, "priority")):
191 dst.priority = src.priority
193 if not getattr(dst, opcodes.COMMENT_ATTR, None):
194 dst.comment = defcomment
197 def _ProcessResult(submit_fn, op, result):
198 """Examines opcode result.
200 If necessary, additional processing on the result is done.
203 if isinstance(result, cmdlib.ResultWithJobs):
204 # Copy basic parameters (e.g. priority)
205 map(compat.partial(_SetBaseOpParams, op,
206 "Submitted by %s" % op.OP_ID),
207 itertools.chain(*result.jobs))
210 job_submission = submit_fn(result.jobs)
213 result = result.other
215 assert constants.JOB_IDS_KEY not in result, \
216 "Key '%s' found in additional return values" % constants.JOB_IDS_KEY
218 result[constants.JOB_IDS_KEY] = job_submission
223 def _FailingSubmitManyJobs(_):
224 """Implementation of L{OpExecCbBase.SubmitManyJobs} to raise an exception.
227 raise errors.ProgrammerError("Opcodes processed without callbacks (e.g."
228 " queries) can not submit jobs")
231 def _RpcResultsToHooksResults(rpc_results):
232 """Function to convert RPC results to the format expected by HooksMaster.
234 @type rpc_results: dict(node: L{rpc.RpcResult})
235 @param rpc_results: RPC results
236 @rtype: dict(node: (fail_msg, offline, hooks_results))
237 @return: RPC results unpacked according to the format expected by
241 return dict((node, (rpc_res.fail_msg, rpc_res.offline, rpc_res.payload))
242 for (node, rpc_res) in rpc_results.items())
245 class Processor(object):
246 """Object which runs OpCodes"""
247 DISPATCH_TABLE = _ComputeDispatchTable()
249 def __init__(self, context, ec_id):
250 """Constructor for Processor
252 @type context: GanetiContext
253 @param context: global Ganeti context
255 @param ec_id: execution context identifier
258 self.context = context
261 self.rpc = context.rpc
262 self.hmclass = HooksMaster
264 def _AcquireLocks(self, level, names, shared, timeout, priority):
265 """Acquires locks via the Ganeti lock manager.
268 @param level: Lock level
269 @type names: list or string
270 @param names: Lock names
272 @param shared: Whether the locks should be acquired in shared mode
273 @type timeout: None or float
274 @param timeout: Timeout for acquiring the locks
275 @raise LockAcquireTimeout: In case locks couldn't be acquired in specified
280 self._cbs.CheckCancel()
282 acquired = self.context.glm.acquire(level, names, shared=shared,
283 timeout=timeout, priority=priority)
286 raise LockAcquireTimeout()
290 def _ExecLU(self, lu):
291 """Logical Unit execution sequence.
294 write_count = self.context.cfg.write_count
297 hm = self.BuildHooksManager(lu)
298 h_results = hm.RunPhase(constants.HOOKS_PHASE_PRE)
299 lu.HooksCallBack(constants.HOOKS_PHASE_PRE, h_results,
302 if getattr(lu.op, "dry_run", False):
303 # in this mode, no post-hooks are run, and the config is not
304 # written (as it might have been modified by another LU, and we
305 # shouldn't do writeout on behalf of other threads
306 self.LogInfo("dry-run mode requested, not actually executing"
308 return lu.dry_run_result
311 submit_mj_fn = self._cbs.SubmitManyJobs
313 submit_mj_fn = _FailingSubmitManyJobs
316 result = _ProcessResult(submit_mj_fn, lu.op, lu.Exec(self.Log))
317 h_results = hm.RunPhase(constants.HOOKS_PHASE_POST)
318 result = lu.HooksCallBack(constants.HOOKS_PHASE_POST, h_results,
321 # FIXME: This needs locks if not lu_class.REQ_BGL
322 if write_count != self.context.cfg.write_count:
327 def BuildHooksManager(self, lu):
328 return self.hmclass.BuildFromLu(lu.rpc.call_hooks_runner, lu)
330 def _LockAndExecLU(self, lu, level, calc_timeout, priority):
331 """Execute a Logical Unit, with the needed locks.
333 This is a recursive function that starts locking the given level, and
334 proceeds up, till there are no more locks to acquire. Then it executes the
335 given LU and its opcodes.
338 adding_locks = level in lu.add_locks
339 acquiring_locks = level in lu.needed_locks
340 if level not in locking.LEVELS:
342 self._cbs.NotifyStart()
344 result = self._ExecLU(lu)
346 elif adding_locks and acquiring_locks:
347 # We could both acquire and add locks at the same level, but for now we
348 # don't need this, so we'll avoid the complicated code needed.
349 raise NotImplementedError("Can't declare locks to acquire when adding"
352 elif adding_locks or acquiring_locks:
353 lu.DeclareLocks(level)
354 share = lu.share_locks[level]
357 assert adding_locks ^ acquiring_locks, \
358 "Locks must be either added or acquired"
362 needed_locks = lu.needed_locks[level]
364 self._AcquireLocks(level, needed_locks, share,
365 calc_timeout(), priority)
368 add_locks = lu.add_locks[level]
369 lu.remove_locks[level] = add_locks
372 self.context.glm.add(level, add_locks, acquired=1, shared=share)
373 except errors.LockError:
374 raise errors.OpPrereqError(
375 "Couldn't add locks (%s), probably because of a race condition"
376 " with another job, who added them first" % add_locks,
380 result = self._LockAndExecLU(lu, level + 1, calc_timeout, priority)
382 if level in lu.remove_locks:
383 self.context.glm.remove(level, lu.remove_locks[level])
385 if self.context.glm.is_owned(level):
386 self.context.glm.release(level)
389 result = self._LockAndExecLU(lu, level + 1, calc_timeout, priority)
393 def ExecOpCode(self, op, cbs, timeout=None, priority=None):
394 """Execute an opcode.
396 @type op: an OpCode instance
397 @param op: the opcode to be executed
398 @type cbs: L{OpExecCbBase}
399 @param cbs: Runtime callbacks
400 @type timeout: float or None
401 @param timeout: Maximum time to acquire all locks, None for no timeout
402 @type priority: number or None
403 @param priority: Priority for acquiring lock(s)
404 @raise LockAcquireTimeout: In case locks couldn't be acquired in specified
408 if not isinstance(op, opcodes.OpCode):
409 raise errors.ProgrammerError("Non-opcode instance passed"
410 " to ExecOpcode (%s)" % type(op))
412 lu_class = self.DISPATCH_TABLE.get(op.__class__, None)
414 raise errors.OpCodeUnknown("Unknown opcode")
417 calc_timeout = lambda: None
419 calc_timeout = utils.RunningTimeout(timeout, False).Remaining
423 # Acquire the Big Ganeti Lock exclusively if this LU requires it,
424 # and in a shared fashion otherwise (to prevent concurrent run with
426 self._AcquireLocks(locking.LEVEL_CLUSTER, locking.BGL,
427 not lu_class.REQ_BGL, calc_timeout(),
430 lu = lu_class(self, op, self.context, self.rpc)
432 assert lu.needed_locks is not None, "needed_locks not set by LU"
435 result = self._LockAndExecLU(lu, locking.LEVEL_INSTANCE, calc_timeout,
439 self.context.cfg.DropECReservations(self._ec_id)
441 self.context.glm.release(locking.LEVEL_CLUSTER)
445 resultcheck_fn = op.OP_RESULT
446 if not (resultcheck_fn is None or resultcheck_fn(result)):
447 logging.error("Expected opcode result matching %s, got %s",
448 resultcheck_fn, result)
449 raise errors.OpResultError("Opcode result does not match %s: %s" %
450 (resultcheck_fn, utils.Truncate(result, 80)))
454 def Log(self, *args):
455 """Forward call to feedback callback function.
459 self._cbs.Feedback(*args)
461 def LogStep(self, current, total, message):
462 """Log a change in LU execution progress.
465 logging.debug("Step %d/%d %s", current, total, message)
466 self.Log("STEP %d/%d %s" % (current, total, message))
468 def LogWarning(self, message, *args, **kwargs):
469 """Log a warning to the logs and the user.
471 The optional keyword argument is 'hint' and can be used to show a
472 hint to the user (presumably related to the warning). If the
473 message is empty, it will not be printed at all, allowing one to
477 assert not kwargs or (len(kwargs) == 1 and "hint" in kwargs), \
478 "Invalid keyword arguments for LogWarning (%s)" % str(kwargs)
480 message = message % tuple(args)
482 logging.warning(message)
483 self.Log(" - WARNING: %s" % message)
485 self.Log(" Hint: %s" % kwargs["hint"])
487 def LogInfo(self, message, *args):
488 """Log an informational message to the logs and the user.
492 message = message % tuple(args)
493 logging.info(message)
494 self.Log(" - INFO: %s" % message)
497 """Returns the current execution context ID.
501 raise errors.ProgrammerError("Tried to use execution context id when"
506 class HooksMaster(object):
507 def __init__(self, opcode, hooks_path, nodes, hooks_execution_fn,
508 hooks_results_adapt_fn, build_env_fn, log_fn, htype=None, cluster_name=None,
510 """Base class for hooks masters.
512 This class invokes the execution of hooks according to the behaviour
513 specified by its parameters.
516 @param opcode: opcode of the operation to which the hooks are tied
517 @type hooks_path: string
518 @param hooks_path: prefix of the hooks directories
519 @type nodes: 2-tuple of lists
520 @param nodes: 2-tuple of lists containing nodes on which pre-hooks must be
521 run and nodes on which post-hooks must be run
522 @type hooks_execution_fn: function that accepts the following parameters:
523 (node_list, hooks_path, phase, environment)
524 @param hooks_execution_fn: function that will execute the hooks; can be
525 None, indicating that no conversion is necessary.
526 @type hooks_results_adapt_fn: function
527 @param hooks_results_adapt_fn: function that will adapt the return value of
528 hooks_execution_fn to the format expected by RunPhase
529 @type build_env_fn: function that returns a dictionary having strings as
531 @param build_env_fn: function that builds the environment for the hooks
532 @type log_fn: function that accepts a string
533 @param log_fn: logging function
534 @type htype: string or None
535 @param htype: None or one of L{constants.HTYPE_CLUSTER},
536 L{constants.HTYPE_NODE}, L{constants.HTYPE_INSTANCE}
537 @type cluster_name: string
538 @param cluster_name: name of the cluster
539 @type master_name: string
540 @param master_name: name of the master
544 self.hooks_path = hooks_path
545 self.hooks_execution_fn = hooks_execution_fn
546 self.hooks_results_adapt_fn = hooks_results_adapt_fn
547 self.build_env_fn = build_env_fn
550 self.cluster_name = cluster_name
551 self.master_name = master_name
553 self.pre_env = self._BuildEnv(constants.HOOKS_PHASE_PRE)
554 (self.pre_nodes, self.post_nodes) = nodes
556 def _BuildEnv(self, phase):
557 """Compute the environment and the target nodes.
559 Based on the opcode and the current node list, this builds the
560 environment for the hooks and the target node list for the run.
563 if phase == constants.HOOKS_PHASE_PRE:
565 elif phase == constants.HOOKS_PHASE_POST:
566 prefix = "GANETI_POST_"
568 raise AssertionError("Unknown phase '%s'" % phase)
572 if self.hooks_path is not None:
573 phase_env = self.build_env_fn()
575 assert not compat.any(key.upper().startswith(prefix)
576 for key in phase_env)
577 env.update(("%s%s" % (prefix, key), value)
578 for (key, value) in phase_env.items())
580 if phase == constants.HOOKS_PHASE_PRE:
581 assert compat.all((key.startswith("GANETI_") and
582 not key.startswith("GANETI_POST_"))
585 elif phase == constants.HOOKS_PHASE_POST:
586 assert compat.all(key.startswith("GANETI_POST_") for key in env)
587 assert isinstance(self.pre_env, dict)
589 # Merge with pre-phase environment
590 assert not compat.any(key.startswith("GANETI_POST_")
591 for key in self.pre_env)
592 env.update(self.pre_env)
594 raise AssertionError("Unknown phase '%s'" % phase)
598 def _RunWrapper(self, node_list, hpath, phase, phase_env):
599 """Simple wrapper over self.callfn.
601 This method fixes the environment before executing the hooks.
605 "PATH": constants.HOOKS_PATH,
606 "GANETI_HOOKS_VERSION": constants.HOOKS_VERSION,
607 "GANETI_OP_CODE": self.opcode,
608 "GANETI_DATA_DIR": constants.DATA_DIR,
609 "GANETI_HOOKS_PHASE": phase,
610 "GANETI_HOOKS_PATH": hpath,
614 env["GANETI_OBJECT_TYPE"] = self.htype
616 if self.cluster_name is not None:
617 env["GANETI_CLUSTER"] = self.cluster_name
619 if self.master_name is not None:
620 env["GANETI_MASTER"] = self.master_name
623 env = utils.algo.JoinDisjointDicts(env, phase_env)
625 # Convert everything to strings
626 env = dict([(str(key), str(val)) for key, val in env.iteritems()])
628 assert compat.all(key == "PATH" or key.startswith("GANETI_")
631 return self.hooks_execution_fn(node_list, hpath, phase, env)
633 def RunPhase(self, phase, nodes=None):
634 """Run all the scripts for a phase.
636 This is the main function of the HookMaster.
637 It executes self.hooks_execution_fn, and after running
638 self.hooks_results_adapt_fn on its results it expects them to be in the form
639 {node_name: (fail_msg, [(script, result, output), ...]}).
641 @param phase: one of L{constants.HOOKS_PHASE_POST} or
642 L{constants.HOOKS_PHASE_PRE}; it denotes the hooks phase
643 @param nodes: overrides the predefined list of nodes for the given phase
644 @return: the processed results of the hooks multi-node rpc call
645 @raise errors.HooksFailure: on communication failure to the nodes
646 @raise errors.HooksAbort: on failure of one of the hooks
649 if phase == constants.HOOKS_PHASE_PRE:
651 nodes = self.pre_nodes
653 elif phase == constants.HOOKS_PHASE_POST:
655 nodes = self.post_nodes
656 env = self._BuildEnv(phase)
658 raise AssertionError("Unknown phase '%s'" % phase)
661 # empty node list, we should not attempt to run this as either
662 # we're in the cluster init phase and the rpc client part can't
663 # even attempt to run, or this LU doesn't do hooks at all
666 results = self._RunWrapper(nodes, self.hooks_path, phase, env)
668 msg = "Communication Failure"
669 if phase == constants.HOOKS_PHASE_PRE:
670 raise errors.HooksFailure(msg)
675 converted_res = results
676 if self.hooks_results_adapt_fn:
677 converted_res = self.hooks_results_adapt_fn(results)
680 for node_name, (fail_msg, offline, hooks_results) in converted_res.items():
685 self.log_fn("Communication failure to node %s: %s", node_name, fail_msg)
688 for script, hkr, output in hooks_results:
689 if hkr == constants.HKR_FAIL:
690 if phase == constants.HOOKS_PHASE_PRE:
691 errs.append((node_name, script, output))
694 output = "(no output)"
695 self.log_fn("On %s script %s failed, output: %s" %
696 (node_name, script, output))
698 if errs and phase == constants.HOOKS_PHASE_PRE:
699 raise errors.HooksAbort(errs)
703 def RunConfigUpdate(self):
704 """Run the special configuration update hook
706 This is a special hook that runs only on the master after each
707 top-level LI if the configuration has been updated.
710 phase = constants.HOOKS_PHASE_POST
711 hpath = constants.HOOKS_NAME_CFGUPDATE
712 nodes = [self.master_name]
713 self._RunWrapper(nodes, hpath, phase, self.pre_env)
716 def BuildFromLu(hooks_execution_fn, lu):
720 nodes = map(frozenset, lu.BuildHooksNodes())
722 master_name = cluster_name = None
724 master_name = lu.cfg.GetMasterNode()
725 cluster_name = lu.cfg.GetClusterName()
727 return HooksMaster(lu.op.OP_ID, lu.HPATH, nodes, hooks_execution_fn,
728 _RpcResultsToHooksResults, lu.BuildHooksEnv,
729 lu.LogWarning, lu.HTYPE, cluster_name, master_name)