ganeti.mcpu

1 # 2 # 3 4 # Copyright (C) 2006, 2007 Google Inc. 5 # 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. 10 # 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. 15 # 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 19 # 02110-1301, USA. 20 21 22 """Module implementing the logic behind the cluster operations 23 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 28 29 """ 30 31 import logging 32 import random 33 import time 34 35 from ganeti import opcodes 36 from ganeti import constants 37 from ganeti import errors 38 from ganeti import rpc 39 from ganeti import cmdlib 40 from ganeti import locking 41 42

43 -class LockAcquireTimeout(Exception):

44 """Exception to report timeouts on acquiring locks. 45 46 """

47 48

49 -def _CalculateLockAttemptTimeouts():

50 """Calculate timeouts for lock attempts. 51 52 """ 53 result = [1.0] 54 55 # Wait for a total of at least 150s before doing a blocking acquire 56 while sum(result) < 150.0: 57 timeout = (result[-1] * 1.05) ** 1.25 58 59 # Cap timeout at 10 seconds. This gives other jobs a chance to run 60 # even if we're still trying to get our locks, before finally moving 61 # to a blocking acquire. 62 if timeout > 10.0: 63 timeout = 10.0 64 65 elif timeout < 0.1: 66 # Lower boundary for safety 67 timeout = 0.1 68 69 result.append(timeout) 70 71 return result

72 73

74 -class LockAttemptTimeoutStrategy(object):

75 """Class with lock acquire timeout strategy. 76 77 """ 78 __slots__ = [ 79 "_timeouts", 80 "_random_fn", 81 "_time_fn", 82 ] 83 84 _TIMEOUT_PER_ATTEMPT = _CalculateLockAttemptTimeouts() 85

86 - def __init__(self, _time_fn=time.time, _random_fn=random.random):

87 """Initializes this class. 88 89 @param _time_fn: Time function for unittests 90 @param _random_fn: Random number generator for unittests 91 92 """ 93 object.__init__(self) 94 95 self._timeouts = iter(self._TIMEOUT_PER_ATTEMPT) 96 self._time_fn = _time_fn 97 self._random_fn = _random_fn

98

99 - def NextAttempt(self):

100 """Returns the timeout for the next attempt. 101 102 """ 103 try: 104 timeout = self._timeouts.next() 105 except StopIteration: 106 # No more timeouts, do blocking acquire 107 timeout = None 108 109 if timeout is not None: 110 # Add a small variation (-/+ 5%) to timeout. This helps in situations 111 # where two or more jobs are fighting for the same lock(s). 112 variation_range = timeout * 0.1 113 timeout += ((self._random_fn() * variation_range) - 114 (variation_range * 0.5)) 115 116 return timeout

117 118

119 -class OpExecCbBase: # pylint: disable-msg=W0232

120 """Base class for OpCode execution callbacks. 121 122 """

123 - def NotifyStart(self):

124 """Called when we are about to execute the LU. 125 126 This function is called when we're about to start the lu's Exec() method, 127 that is, after we have acquired all locks. 128 129 """

130

131 - def Feedback(self, *args):

132 """Sends feedback from the LU code to the end-user. 133 134 """

135

136 - def CheckCancel(self):

137 """Check whether job has been cancelled. 138 139 """

140 141

142 -class Processor(object):

143 """Object which runs OpCodes""" 144 DISPATCH_TABLE = { 145 # Cluster 146 opcodes.OpPostInitCluster: cmdlib.LUPostInitCluster, 147 opcodes.OpDestroyCluster: cmdlib.LUDestroyCluster, 148 opcodes.OpQueryClusterInfo: cmdlib.LUQueryClusterInfo, 149 opcodes.OpVerifyCluster: cmdlib.LUVerifyCluster, 150 opcodes.OpQueryConfigValues: cmdlib.LUQueryConfigValues, 151 opcodes.OpRenameCluster: cmdlib.LURenameCluster, 152 opcodes.OpVerifyDisks: cmdlib.LUVerifyDisks, 153 opcodes.OpSetClusterParams: cmdlib.LUSetClusterParams, 154 opcodes.OpRedistributeConfig: cmdlib.LURedistributeConfig, 155 opcodes.OpRepairDiskSizes: cmdlib.LURepairDiskSizes, 156 # node lu 157 opcodes.OpAddNode: cmdlib.LUAddNode, 158 opcodes.OpQueryNodes: cmdlib.LUQueryNodes, 159 opcodes.OpQueryNodeVolumes: cmdlib.LUQueryNodeVolumes, 160 opcodes.OpQueryNodeStorage: cmdlib.LUQueryNodeStorage, 161 opcodes.OpModifyNodeStorage: cmdlib.LUModifyNodeStorage, 162 opcodes.OpRepairNodeStorage: cmdlib.LURepairNodeStorage, 163 opcodes.OpRemoveNode: cmdlib.LURemoveNode, 164 opcodes.OpSetNodeParams: cmdlib.LUSetNodeParams, 165 opcodes.OpPowercycleNode: cmdlib.LUPowercycleNode, 166 opcodes.OpMigrateNode: cmdlib.LUMigrateNode, 167 opcodes.OpNodeEvacuationStrategy: cmdlib.LUNodeEvacuationStrategy, 168 # instance lu 169 opcodes.OpCreateInstance: cmdlib.LUCreateInstance, 170 opcodes.OpReinstallInstance: cmdlib.LUReinstallInstance, 171 opcodes.OpRemoveInstance: cmdlib.LURemoveInstance, 172 opcodes.OpRenameInstance: cmdlib.LURenameInstance, 173 opcodes.OpActivateInstanceDisks: cmdlib.LUActivateInstanceDisks, 174 opcodes.OpShutdownInstance: cmdlib.LUShutdownInstance, 175 opcodes.OpStartupInstance: cmdlib.LUStartupInstance, 176 opcodes.OpRebootInstance: cmdlib.LURebootInstance, 177 opcodes.OpDeactivateInstanceDisks: cmdlib.LUDeactivateInstanceDisks, 178 opcodes.OpReplaceDisks: cmdlib.LUReplaceDisks, 179 opcodes.OpRecreateInstanceDisks: cmdlib.LURecreateInstanceDisks, 180 opcodes.OpFailoverInstance: cmdlib.LUFailoverInstance, 181 opcodes.OpMigrateInstance: cmdlib.LUMigrateInstance, 182 opcodes.OpMoveInstance: cmdlib.LUMoveInstance, 183 opcodes.OpConnectConsole: cmdlib.LUConnectConsole, 184 opcodes.OpQueryInstances: cmdlib.LUQueryInstances, 185 opcodes.OpQueryInstanceData: cmdlib.LUQueryInstanceData, 186 opcodes.OpSetInstanceParams: cmdlib.LUSetInstanceParams, 187 opcodes.OpGrowDisk: cmdlib.LUGrowDisk, 188 # os lu 189 opcodes.OpDiagnoseOS: cmdlib.LUDiagnoseOS, 190 # exports lu 191 opcodes.OpQueryExports: cmdlib.LUQueryExports, 192 opcodes.OpPrepareExport: cmdlib.LUPrepareExport, 193 opcodes.OpExportInstance: cmdlib.LUExportInstance, 194 opcodes.OpRemoveExport: cmdlib.LURemoveExport, 195 # tags lu 196 opcodes.OpGetTags: cmdlib.LUGetTags, 197 opcodes.OpSearchTags: cmdlib.LUSearchTags, 198 opcodes.OpAddTags: cmdlib.LUAddTags, 199 opcodes.OpDelTags: cmdlib.LUDelTags, 200 # test lu 201 opcodes.OpTestDelay: cmdlib.LUTestDelay, 202 opcodes.OpTestAllocator: cmdlib.LUTestAllocator, 203 opcodes.OpTestJobqueue: cmdlib.LUTestJobqueue, 204 } 205

206 - def __init__(self, context, ec_id):

207 """Constructor for Processor 208 209 @type context: GanetiContext 210 @param context: global Ganeti context 211 @type ec_id: string 212 @param ec_id: execution context identifier 213 214 """ 215 self.context = context 216 self._ec_id = ec_id 217 self._cbs = None 218 self.rpc = rpc.RpcRunner(context.cfg) 219 self.hmclass = HooksMaster

220

221 - def _AcquireLocks(self, level, names, shared, timeout, priority):

222 """Acquires locks via the Ganeti lock manager. 223 224 @type level: int 225 @param level: Lock level 226 @type names: list or string 227 @param names: Lock names 228 @type shared: bool 229 @param shared: Whether the locks should be acquired in shared mode 230 @type timeout: None or float 231 @param timeout: Timeout for acquiring the locks 232 @raise LockAcquireTimeout: In case locks couldn't be acquired in specified 233 amount of time 234 235 """ 236 if self._cbs: 237 self._cbs.CheckCancel() 238 239 acquired = self.context.glm.acquire(level, names, shared=shared, 240 timeout=timeout, priority=priority) 241 242 if acquired is None: 243 raise LockAcquireTimeout() 244 245 return acquired

246

247 - def _ExecLU(self, lu):

248 """Logical Unit execution sequence. 249 250 """ 251 write_count = self.context.cfg.write_count 252 lu.CheckPrereq() 253 hm = HooksMaster(self.rpc.call_hooks_runner, lu) 254 h_results = hm.RunPhase(constants.HOOKS_PHASE_PRE) 255 lu.HooksCallBack(constants.HOOKS_PHASE_PRE, h_results, 256 self.Log, None) 257 258 if getattr(lu.op, "dry_run", False): 259 # in this mode, no post-hooks are run, and the config is not 260 # written (as it might have been modified by another LU, and we 261 # shouldn't do writeout on behalf of other threads 262 self.LogInfo("dry-run mode requested, not actually executing" 263 " the operation") 264 return lu.dry_run_result 265 266 try: 267 result = lu.Exec(self.Log) 268 h_results = hm.RunPhase(constants.HOOKS_PHASE_POST) 269 result = lu.HooksCallBack(constants.HOOKS_PHASE_POST, h_results, 270 self.Log, result) 271 finally: 272 # FIXME: This needs locks if not lu_class.REQ_BGL 273 if write_count != self.context.cfg.write_count: 274 hm.RunConfigUpdate() 275 276 return result

277

278 - def _LockAndExecLU(self, lu, level, calc_timeout, priority):

279 """Execute a Logical Unit, with the needed locks. 280 281 This is a recursive function that starts locking the given level, and 282 proceeds up, till there are no more locks to acquire. Then it executes the 283 given LU and its opcodes. 284 285 """ 286 adding_locks = level in lu.add_locks 287 acquiring_locks = level in lu.needed_locks 288 if level not in locking.LEVELS: 289 if self._cbs: 290 self._cbs.NotifyStart() 291 292 result = self._ExecLU(lu) 293 294 elif adding_locks and acquiring_locks: 295 # We could both acquire and add locks at the same level, but for now we 296 # don't need this, so we'll avoid the complicated code needed. 297 raise NotImplementedError("Can't declare locks to acquire when adding" 298 " others") 299 300 elif adding_locks or acquiring_locks: 301 lu.DeclareLocks(level) 302 share = lu.share_locks[level] 303 304 try: 305 assert adding_locks ^ acquiring_locks, \ 306 "Locks must be either added or acquired" 307 308 if acquiring_locks: 309 # Acquiring locks 310 needed_locks = lu.needed_locks[level] 311 312 acquired = self._AcquireLocks(level, needed_locks, share, 313 calc_timeout(), priority) 314 else: 315 # Adding locks 316 add_locks = lu.add_locks[level] 317 lu.remove_locks[level] = add_locks 318 319 try: 320 self.context.glm.add(level, add_locks, acquired=1, shared=share) 321 except errors.LockError: 322 raise errors.OpPrereqError( 323 "Couldn't add locks (%s), probably because of a race condition" 324 " with another job, who added them first" % add_locks, 325 errors.ECODE_FAULT) 326 327 acquired = add_locks 328 329 try: 330 lu.acquired_locks[level] = acquired 331 332 result = self._LockAndExecLU(lu, level + 1, calc_timeout, priority) 333 finally: 334 if level in lu.remove_locks: 335 self.context.glm.remove(level, lu.remove_locks[level]) 336 finally: 337 if self.context.glm.is_owned(level): 338 self.context.glm.release(level) 339 340 else: 341 result = self._LockAndExecLU(lu, level + 1, calc_timeout, priority) 342 343 return result

344

345 - def ExecOpCode(self, op, cbs, timeout=None, priority=None):

346 """Execute an opcode. 347 348 @type op: an OpCode instance 349 @param op: the opcode to be executed 350 @type cbs: L{OpExecCbBase} 351 @param cbs: Runtime callbacks 352 @type timeout: float or None 353 @param timeout: Maximum time to acquire all locks, None for no timeout 354 @type priority: number or None 355 @param priority: Priority for acquiring lock(s) 356 @raise LockAcquireTimeout: In case locks couldn't be acquired in specified 357 amount of time 358 359 """ 360 if not isinstance(op, opcodes.OpCode): 361 raise errors.ProgrammerError("Non-opcode instance passed" 362 " to ExecOpcode") 363 364 lu_class = self.DISPATCH_TABLE.get(op.__class__, None) 365 if lu_class is None: 366 raise errors.OpCodeUnknown("Unknown opcode") 367 368 if timeout is None: 369 calc_timeout = lambda: None 370 else: 371 calc_timeout = locking.RunningTimeout(timeout, False).Remaining 372 373 self._cbs = cbs 374 try: 375 # Acquire the Big Ganeti Lock exclusively if this LU requires it, 376 # and in a shared fashion otherwise (to prevent concurrent run with 377 # an exclusive LU. 378 self._AcquireLocks(locking.LEVEL_CLUSTER, locking.BGL, 379 not lu_class.REQ_BGL, calc_timeout(), 380 priority) 381 try: 382 lu = lu_class(self, op, self.context, self.rpc) 383 lu.ExpandNames() 384 assert lu.needed_locks is not None, "needed_locks not set by LU" 385 386 try: 387 return self._LockAndExecLU(lu, locking.LEVEL_INSTANCE, calc_timeout, 388 priority) 389 finally: 390 if self._ec_id: 391 self.context.cfg.DropECReservations(self._ec_id) 392 finally: 393 self.context.glm.release(locking.LEVEL_CLUSTER) 394 finally: 395 self._cbs = None

396

397 - def Log(self, *args):

398 """Forward call to feedback callback function. 399 400 """ 401 if self._cbs: 402 self._cbs.Feedback(*args)

403

404 - def LogStep(self, current, total, message):

405 """Log a change in LU execution progress. 406 407 """ 408 logging.debug("Step %d/%d %s", current, total, message) 409 self.Log("STEP %d/%d %s" % (current, total, message))

410

411 - def LogWarning(self, message, *args, **kwargs):

412 """Log a warning to the logs and the user. 413 414 The optional keyword argument is 'hint' and can be used to show a 415 hint to the user (presumably related to the warning). If the 416 message is empty, it will not be printed at all, allowing one to 417 show only a hint. 418 419 """ 420 assert not kwargs or (len(kwargs) == 1 and "hint" in kwargs), \ 421 "Invalid keyword arguments for LogWarning (%s)" % str(kwargs) 422 if args: 423 message = message % tuple(args) 424 if message: 425 logging.warning(message) 426 self.Log(" - WARNING: %s" % message) 427 if "hint" in kwargs: 428 self.Log(" Hint: %s" % kwargs["hint"])

429

430 - def LogInfo(self, message, *args):

431 """Log an informational message to the logs and the user. 432 433 """ 434 if args: 435 message = message % tuple(args) 436 logging.info(message) 437 self.Log(" - INFO: %s" % message)

438

439 - def GetECId(self):

440 if not self._ec_id: 441 errors.ProgrammerError("Tried to use execution context id when not set") 442 return self._ec_id

443 444

445 -class HooksMaster(object):

446 """Hooks master. 447 448 This class distributes the run commands to the nodes based on the 449 specific LU class. 450 451 In order to remove the direct dependency on the rpc module, the 452 constructor needs a function which actually does the remote 453 call. This will usually be rpc.call_hooks_runner, but any function 454 which behaves the same works. 455 456 """

457 - def __init__(self, callfn, lu):

458 self.callfn = callfn 459 self.lu = lu 460 self.op = lu.op 461 self.env, node_list_pre, node_list_post = self._BuildEnv() 462 self.node_list = {constants.HOOKS_PHASE_PRE: node_list_pre, 463 constants.HOOKS_PHASE_POST: node_list_post}

464

465 - def _BuildEnv(self):

466 """Compute the environment and the target nodes. 467 468 Based on the opcode and the current node list, this builds the 469 environment for the hooks and the target node list for the run. 470 471 """ 472 env = { 473 "PATH": "/sbin:/bin:/usr/sbin:/usr/bin", 474 "GANETI_HOOKS_VERSION": constants.HOOKS_VERSION, 475 "GANETI_OP_CODE": self.op.OP_ID, 476 "GANETI_OBJECT_TYPE": self.lu.HTYPE, 477 "GANETI_DATA_DIR": constants.DATA_DIR, 478 } 479 480 if self.lu.HPATH is not None: 481 lu_env, lu_nodes_pre, lu_nodes_post = self.lu.BuildHooksEnv() 482 if lu_env: 483 for key in lu_env: 484 env["GANETI_" + key] = lu_env[key] 485 else: 486 lu_nodes_pre = lu_nodes_post = [] 487 488 return env, frozenset(lu_nodes_pre), frozenset(lu_nodes_post)

489

490 - def _RunWrapper(self, node_list, hpath, phase):

491 """Simple wrapper over self.callfn. 492 493 This method fixes the environment before doing the rpc call. 494 495 """ 496 env = self.env.copy() 497 env["GANETI_HOOKS_PHASE"] = phase 498 env["GANETI_HOOKS_PATH"] = hpath 499 if self.lu.cfg is not None: 500 env["GANETI_CLUSTER"] = self.lu.cfg.GetClusterName() 501 env["GANETI_MASTER"] = self.lu.cfg.GetMasterNode() 502 503 env = dict([(str(key), str(val)) for key, val in env.iteritems()]) 504 505 return self.callfn(node_list, hpath, phase, env)

506

507 - def RunPhase(self, phase, nodes=None):

508 """Run all the scripts for a phase. 509 510 This is the main function of the HookMaster. 511 512 @param phase: one of L{constants.HOOKS_PHASE_POST} or 513 L{constants.HOOKS_PHASE_PRE}; it denotes the hooks phase 514 @param nodes: overrides the predefined list of nodes for the given phase 515 @return: the processed results of the hooks multi-node rpc call 516 @raise errors.HooksFailure: on communication failure to the nodes 517 @raise errors.HooksAbort: on failure of one of the hooks 518 519 """ 520 if not self.node_list[phase] and not nodes: 521 # empty node list, we should not attempt to run this as either 522 # we're in the cluster init phase and the rpc client part can't 523 # even attempt to run, or this LU doesn't do hooks at all 524 return 525 hpath = self.lu.HPATH 526 if nodes is not None: 527 results = self._RunWrapper(nodes, hpath, phase) 528 else: 529 results = self._RunWrapper(self.node_list[phase], hpath, phase) 530 errs = [] 531 if not results: 532 msg = "Communication Failure" 533 if phase == constants.HOOKS_PHASE_PRE: 534 raise errors.HooksFailure(msg) 535 else: 536 self.lu.LogWarning(msg) 537 return results 538 for node_name in results: 539 res = results[node_name] 540 if res.offline: 541 continue 542 msg = res.fail_msg 543 if msg: 544 self.lu.LogWarning("Communication failure to node %s: %s", 545 node_name, msg) 546 continue 547 for script, hkr, output in res.payload: 548 if hkr == constants.HKR_FAIL: 549 if phase == constants.HOOKS_PHASE_PRE: 550 errs.append((node_name, script, output)) 551 else: 552 if not output: 553 output = "(no output)" 554 self.lu.LogWarning("On %s script %s failed, output: %s" % 555 (node_name, script, output)) 556 if errs and phase == constants.HOOKS_PHASE_PRE: 557 raise errors.HooksAbort(errs) 558 return results

559

560 - def RunConfigUpdate(self):

561 """Run the special configuration update hook 562 563 This is a special hook that runs only on the master after each 564 top-level LI if the configuration has been updated. 565 566 """ 567 phase = constants.HOOKS_PHASE_POST 568 hpath = constants.HOOKS_NAME_CFGUPDATE 569 nodes = [self.lu.cfg.GetMasterNode()] 570 self._RunWrapper(nodes, hpath, phase)

571

Source Code for Module ganeti.mcpu