# # # Copyright (C) 2006, 2007, 2008 Google Inc. # # 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. """Module implementing the job queue handling. Locking: There's a single, large lock in the JobQueue class. It's used by all other classes in this module. """ import os import logging import threading import errno import re import time import weakref from ganeti import constants from ganeti import serializer from ganeti import workerpool from ganeti import opcodes from ganeti import errors from ganeti import mcpu from ganeti import utils from ganeti import jstore from ganeti import rpc from ganeti.rpc import RpcRunner JOBQUEUE_THREADS = 25 def TimeStampNow(): return utils.SplitTime(time.time()) class _QueuedOpCode(object): """Encasulates an opcode object. The 'log' attribute holds the execution log and consists of tuples of the form (log_serial, timestamp, level, message). """ def __init__(self, op): self.input = op self.status = constants.OP_STATUS_QUEUED self.result = None self.log = [] self.start_timestamp = None self.end_timestamp = None @classmethod def Restore(cls, state): obj = _QueuedOpCode.__new__(cls) obj.input = opcodes.OpCode.LoadOpCode(state["input"]) obj.status = state["status"] obj.result = state["result"] obj.log = state["log"] obj.start_timestamp = state.get("start_timestamp", None) obj.end_timestamp = state.get("end_timestamp", None) return obj def Serialize(self): return { "input": self.input.__getstate__(), "status": self.status, "result": self.result, "log": self.log, "start_timestamp": self.start_timestamp, "end_timestamp": self.end_timestamp, } class _QueuedJob(object): """In-memory job representation. This is what we use to track the user-submitted jobs. Locking must be taken care of by users of this class. """ def __init__(self, queue, job_id, ops): if not ops: # TODO raise Exception("No opcodes") self.queue = queue self.id = job_id self.ops = [_QueuedOpCode(op) for op in ops] self.run_op_index = -1 self.log_serial = 0 self.received_timestamp = TimeStampNow() self.start_timestamp = None self.end_timestamp = None # Condition to wait for changes self.change = threading.Condition(self.queue._lock) @classmethod def Restore(cls, queue, state): obj = _QueuedJob.__new__(cls) obj.queue = queue obj.id = state["id"] obj.run_op_index = state["run_op_index"] obj.received_timestamp = state.get("received_timestamp", None) obj.start_timestamp = state.get("start_timestamp", None) obj.end_timestamp = state.get("end_timestamp", None) 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) # Condition to wait for changes obj.change = threading.Condition(obj.queue._lock) return obj def Serialize(self): return { "id": self.id, "ops": [op.Serialize() for op in self.ops], "run_op_index": self.run_op_index, "start_timestamp": self.start_timestamp, "end_timestamp": self.end_timestamp, "received_timestamp": self.received_timestamp, } def CalcStatus(self): status = constants.JOB_STATUS_QUEUED all_success = True for op in self.ops: if op.status == constants.OP_STATUS_SUCCESS: continue all_success = False if op.status == constants.OP_STATUS_QUEUED: pass elif op.status == constants.OP_STATUS_WAITLOCK: status = constants.JOB_STATUS_WAITLOCK elif op.status == constants.OP_STATUS_RUNNING: status = constants.JOB_STATUS_RUNNING elif op.status == constants.OP_STATUS_ERROR: status = constants.JOB_STATUS_ERROR # The whole job fails if one opcode failed break elif op.status == constants.OP_STATUS_CANCELED: status = constants.OP_STATUS_CANCELED break if all_success: status = constants.JOB_STATUS_SUCCESS return status def GetLogEntries(self, newer_than): if newer_than is None: serial = -1 else: serial = newer_than entries = [] for op in self.ops: entries.extend(filter(lambda entry: entry[0] > newer_than, op.log)) return entries class _JobQueueWorker(workerpool.BaseWorker): def _NotifyStart(self): """Mark the opcode as running, not lock-waiting. 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. """ assert self.queue, "Queue attribute is missing" assert self.opcode, "Opcode attribute is missing" self.queue.acquire() try: self.opcode.status = constants.OP_STATUS_RUNNING finally: self.queue.release() def RunTask(self, job): """Job executor. This functions processes a job. It is closely tied to the _QueuedJob and _QueuedOpCode classes. """ logging.debug("Worker %s processing job %s", self.worker_id, job.id) proc = mcpu.Processor(self.pool.queue.context) self.queue = queue = job.queue try: try: count = len(job.ops) for idx, op in enumerate(job.ops): try: logging.debug("Op %s/%s: Starting %s", idx + 1, count, op) queue.acquire() try: job.run_op_index = idx op.status = constants.OP_STATUS_WAITLOCK op.result = None op.start_timestamp = TimeStampNow() if idx == 0: # first opcode job.start_timestamp = op.start_timestamp queue.UpdateJobUnlocked(job) input_opcode = op.input finally: queue.release() def _Log(*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()) queue.acquire() try: job.log_serial += 1 op.log.append((job.log_serial, timestamp, log_type, log_msg)) job.change.notifyAll() finally: queue.release() # Make sure not to hold lock while _Log is called self.opcode = op result = proc.ExecOpCode(input_opcode, _Log, self._NotifyStart) queue.acquire() try: op.status = constants.OP_STATUS_SUCCESS op.result = result op.end_timestamp = TimeStampNow() queue.UpdateJobUnlocked(job) finally: queue.release() logging.debug("Op %s/%s: Successfully finished %s", idx + 1, count, op) except Exception, err: queue.acquire() try: try: op.status = constants.OP_STATUS_ERROR op.result = str(err) op.end_timestamp = TimeStampNow() logging.debug("Op %s/%s: Error in %s", idx + 1, count, op) finally: queue.UpdateJobUnlocked(job) finally: queue.release() raise except errors.GenericError, err: logging.exception("Ganeti exception") except: logging.exception("Unhandled exception") finally: queue.acquire() try: try: job.run_op_idx = -1 job.end_timestamp = TimeStampNow() queue.UpdateJobUnlocked(job) finally: job_id = job.id status = job.CalcStatus() finally: queue.release() logging.debug("Worker %s finished job %s, status = %s", self.worker_id, job_id, status) class _JobQueueWorkerPool(workerpool.WorkerPool): def __init__(self, queue): super(_JobQueueWorkerPool, self).__init__(JOBQUEUE_THREADS, _JobQueueWorker) self.queue = queue class JobQueue(object): _RE_JOB_FILE = re.compile(r"^job-(%s)$" % constants.JOB_ID_TEMPLATE) def _RequireOpenQueue(fn): """Decorator for "public" functions. This function should be used for all "public" functions. That is, functions usually called from other classes. Important: Use this decorator only after utils.LockedMethod! Example: @utils.LockedMethod @_RequireOpenQueue def Example(self): pass """ def wrapper(self, *args, **kwargs): assert self._queue_lock is not None, "Queue should be open" return fn(self, *args, **kwargs) return wrapper def __init__(self, context): self.context = context self._memcache = weakref.WeakValueDictionary() self._my_hostname = utils.HostInfo().name # Locking self._lock = threading.Lock() self.acquire = self._lock.acquire self.release = self._lock.release # Initialize self._queue_lock = jstore.InitAndVerifyQueue(must_lock=True) # 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") # Get initial list of nodes self._nodes = set(self.context.cfg.GetNodeList()) # Remove master node try: self._nodes.remove(self._my_hostname) except ValueError: pass # TODO: Check consistency across nodes # Setup worker pool self._wpool = _JobQueueWorkerPool(self) # We need to lock here because WorkerPool.AddTask() may start a job while # we're still doing our work. self.acquire() try: for job in self._GetJobsUnlocked(None): status = job.CalcStatus() if status in (constants.JOB_STATUS_QUEUED, ): self._wpool.AddTask(job) elif status in (constants.JOB_STATUS_RUNNING, constants.JOB_STATUS_WAITLOCK): logging.warning("Unfinished job %s found: %s", job.id, job) try: for op in job.ops: op.status = constants.OP_STATUS_ERROR op.result = "Unclean master daemon shutdown" finally: self.UpdateJobUnlocked(job) finally: self.release() @utils.LockedMethod @_RequireOpenQueue def AddNode(self, node_name): assert node_name != self._my_hostname # Clean queue directory on added node RpcRunner.call_jobqueue_purge(node_name) # Upload the whole queue excluding archived jobs files = [self._GetJobPath(job_id) for job_id in self._GetJobIDsUnlocked()] # Upload current serial file files.append(constants.JOB_QUEUE_SERIAL_FILE) for file_name in files: # Read file content fd = open(file_name, "r") try: content = fd.read() finally: fd.close() result = RpcRunner.call_jobqueue_update([node_name], file_name, content) if not result[node_name]: logging.error("Failed to upload %s to %s", file_name, node_name) self._nodes.add(node_name) @utils.LockedMethod @_RequireOpenQueue def RemoveNode(self, node_name): try: # The queue is removed by the "leave node" RPC call. self._nodes.remove(node_name) except KeyError: pass def _CheckRpcResult(self, result, nodes, failmsg): failed = [] success = [] for node in nodes: if result[node]: success.append(node) else: failed.append(node) if failed: logging.error("%s failed on %s", failmsg, ", ".join(failed)) # +1 for the master node if (len(success) + 1) < len(failed): # TODO: Handle failing nodes logging.error("More than half of the nodes failed") def _WriteAndReplicateFileUnlocked(self, file_name, data): """Writes a file locally and then replicates it to all nodes. """ utils.WriteFile(file_name, data=data) result = RpcRunner.call_jobqueue_update(self._nodes, file_name, data) self._CheckRpcResult(result, self._nodes, "Updating %s" % file_name) def _RenameFileUnlocked(self, old, new): os.rename(old, new) result = RpcRunner.call_jobqueue_rename(self._nodes, old, new) self._CheckRpcResult(result, self._nodes, "Moving %s to %s" % (old, new)) def _FormatJobID(self, job_id): 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) def _NewSerialUnlocked(self): """Generates a new job identifier. Job identifiers are unique during the lifetime of a cluster. Returns: A string representing the job identifier. """ # New number serial = self._last_serial + 1 # Write to file self._WriteAndReplicateFileUnlocked(constants.JOB_QUEUE_SERIAL_FILE, "%s\n" % serial) # Keep it only if we were able to write the file self._last_serial = serial return self._FormatJobID(serial) @staticmethod def _GetJobPath(job_id): return os.path.join(constants.QUEUE_DIR, "job-%s" % job_id) @staticmethod def _GetArchivedJobPath(job_id): return os.path.join(constants.JOB_QUEUE_ARCHIVE_DIR, "job-%s" % job_id) @classmethod def _ExtractJobID(cls, name): m = cls._RE_JOB_FILE.match(name) if m: return m.group(1) else: return None def _GetJobIDsUnlocked(self, archived=False): """Return all known job IDs. If the parameter archived is True, archived jobs IDs will be included. Currently this argument is unused. The method only looks at disk because it's a requirement that all jobs are present on disk (so in the _memcache we don't have any extra IDs). """ jlist = [self._ExtractJobID(name) for name in self._ListJobFiles()] jlist = utils.NiceSort(jlist) return jlist def _ListJobFiles(self): return [name for name in utils.ListVisibleFiles(constants.QUEUE_DIR) if self._RE_JOB_FILE.match(name)] def _LoadJobUnlocked(self, job_id): job = self._memcache.get(job_id, None) if job: logging.debug("Found job %s in memcache", job_id) return job filepath = self._GetJobPath(job_id) logging.debug("Loading job from %s", filepath) try: fd = open(filepath, "r") except IOError, err: if err.errno in (errno.ENOENT, ): return None raise try: data = serializer.LoadJson(fd.read()) finally: fd.close() job = _QueuedJob.Restore(self, data) self._memcache[job_id] = job logging.debug("Added job %s to the cache", job_id) return job def _GetJobsUnlocked(self, job_ids): if not job_ids: job_ids = self._GetJobIDsUnlocked() return [self._LoadJobUnlocked(job_id) for job_id in job_ids] @utils.LockedMethod @_RequireOpenQueue def SubmitJob(self, ops): """Create and store a new job. This enters the job into our job queue and also puts it on the new queue, in order for it to be picked up by the queue processors. @type ops: list @param ops: The list of OpCodes that will become the new job. """ # Get job identifier job_id = self._NewSerialUnlocked() job = _QueuedJob(self, job_id, ops) # Write to disk self.UpdateJobUnlocked(job) logging.debug("Adding new job %s to the cache", job_id) self._memcache[job_id] = job # Add to worker pool self._wpool.AddTask(job) return job.id @_RequireOpenQueue def UpdateJobUnlocked(self, job): filename = self._GetJobPath(job.id) data = serializer.DumpJson(job.Serialize(), indent=False) logging.debug("Writing job %s to %s", job.id, filename) self._WriteAndReplicateFileUnlocked(filename, data) # Notify waiters about potential changes job.change.notifyAll() @utils.LockedMethod @_RequireOpenQueue def WaitForJobChanges(self, job_id, fields, prev_job_info, prev_log_serial, timeout): """Waits for changes in a job. @type job_id: string @param job_id: Job identifier @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 """ logging.debug("Waiting for changes in job %s", job_id) end_time = time.time() + timeout while True: delta_time = end_time - time.time() if delta_time < 0: return constants.JOB_NOTCHANGED job = self._LoadJobUnlocked(job_id) if not job: logging.debug("Job %s not found", job_id) break status = job.CalcStatus() job_info = self._GetJobInfoUnlocked(job, fields) log_entries = job.GetLogEntries(prev_log_serial) # 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. job_info = serializer.LoadJson(serializer.DumpJson(job_info)) log_entries = serializer.LoadJson(serializer.DumpJson(log_entries)) if status not in (constants.JOB_STATUS_QUEUED, constants.JOB_STATUS_RUNNING, constants.JOB_STATUS_WAITLOCK): # Don't even try to wait if the job is no longer running, there will be # no changes. break if (prev_job_info != job_info or (log_entries and prev_log_serial != log_entries[0][0])): break logging.debug("Waiting again") # Release the queue lock while waiting job.change.wait(delta_time) logging.debug("Job %s changed", job_id) return (job_info, log_entries) @utils.LockedMethod @_RequireOpenQueue def CancelJob(self, job_id): """Cancels a job. @type job_id: string @param job_id: Job ID of job to be cancelled. """ logging.debug("Cancelling job %s", job_id) job = self._LoadJobUnlocked(job_id) if not job: logging.debug("Job %s not found", job_id) return if job.CalcStatus() not in (constants.JOB_STATUS_QUEUED,): logging.debug("Job %s is no longer in the queue", job.id) return try: for op in job.ops: op.status = constants.OP_STATUS_ERROR op.result = "Job cancelled by request" finally: self.UpdateJobUnlocked(job) @_RequireOpenQueue def _ArchiveJobUnlocked(self, job_id): """Archives a job. @type job_id: string @param job_id: Job ID of job to be archived. """ logging.info("Archiving job %s", job_id) job = self._LoadJobUnlocked(job_id) if not job: logging.debug("Job %s not found", job_id) return if job.CalcStatus() not in (constants.JOB_STATUS_CANCELED, constants.JOB_STATUS_SUCCESS, constants.JOB_STATUS_ERROR): logging.debug("Job %s is not yet done", job.id) return old = self._GetJobPath(job.id) new = self._GetArchivedJobPath(job.id) self._RenameFileUnlocked(old, new) logging.debug("Successfully archived job %s", job.id) @utils.LockedMethod @_RequireOpenQueue def ArchiveJob(self, job_id): """Archives a job. @type job_id: string @param job_id: Job ID of job to be archived. """ return self._ArchiveJobUnlocked(job_id) @utils.LockedMethod @_RequireOpenQueue def AutoArchiveJobs(self, age): """Archives all jobs based on age. The method will archive all jobs which are older than the age parameter. For jobs that don't have an end timestamp, the start timestamp will be considered. The special '-1' age will cause archival of all jobs (that are not running or queued). @type age: int @param age: the minimum age in seconds """ logging.info("Archiving jobs with age more than %s seconds", age) now = time.time() for jid in self._GetJobIDsUnlocked(archived=False): job = self._LoadJobUnlocked(jid) if job.CalcStatus() not in (constants.OP_STATUS_SUCCESS, constants.OP_STATUS_ERROR, constants.OP_STATUS_CANCELED): continue if job.end_timestamp is None: if job.start_timestamp is None: job_age = job.received_timestamp else: job_age = job.start_timestamp else: job_age = job.end_timestamp if age == -1 or now - job_age[0] > age: self._ArchiveJobUnlocked(jid) def _GetJobInfoUnlocked(self, job, fields): row = [] for fname in fields: if fname == "id": row.append(job.id) elif fname == "status": row.append(job.CalcStatus()) elif fname == "ops": row.append([op.input.__getstate__() for op in job.ops]) elif fname == "opresult": row.append([op.result for op in job.ops]) elif fname == "opstatus": row.append([op.status for op in job.ops]) elif fname == "oplog": row.append([op.log for op in job.ops]) elif fname == "opstart": row.append([op.start_timestamp for op in job.ops]) elif fname == "opend": row.append([op.end_timestamp for op in job.ops]) elif fname == "received_ts": row.append(job.received_timestamp) elif fname == "start_ts": row.append(job.start_timestamp) elif fname == "end_ts": row.append(job.end_timestamp) elif fname == "summary": row.append([op.input.Summary() for op in job.ops]) else: raise errors.OpExecError("Invalid job query field '%s'" % fname) return row @utils.LockedMethod @_RequireOpenQueue def QueryJobs(self, job_ids, fields): """Returns a list of jobs in queue. Args: - job_ids: Sequence of job identifiers or None for all - fields: Names of fields to return """ jobs = [] for job in self._GetJobsUnlocked(job_ids): if job is None: jobs.append(None) else: jobs.append(self._GetJobInfoUnlocked(job, fields)) return jobs @utils.LockedMethod @_RequireOpenQueue def Shutdown(self): """Stops the job queue. """ self._wpool.TerminateWorkers() self._queue_lock.Close() self._queue_lock = None