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Iustin Pop authored
This is mostly: - whitespace fix (space at EOL in some files, not all, broken indentation, etc) - variable names overriding others (one is a real bug in there) - too-long-lines - cleanup of most unused imports (not all) Reviewed-by: ultrotter38206f3c
jqueue.py 17.06 KiB
#
#
# Copyright (C) 2006, 2007 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."""
import os
import logging
import threading
import errno
import re
import time
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 rpc
JOBQUEUE_THREADS = 5
class _QueuedOpCode(object):
"""Encasulates an opcode object.
Access is synchronized by the '_lock' attribute.
The 'log' attribute holds the execution log and consists of tuples
of the form (timestamp, level, message).
"""
def __new__(cls, *args, **kwargs):
obj = object.__new__(cls, *args, **kwargs)
# Create a special lock for logging
obj._log_lock = threading.Lock()
return obj
def __init__(self, op):
self.input = op
self.status = constants.OP_STATUS_QUEUED
self.result = None
self.log = []
@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"]
return obj
def Serialize(self):
self._log_lock.acquire()
try:
return {
"input": self.input.__getstate__(),
"status": self.status,
"result": self.result,
"log": self.log,
}
finally:
self._log_lock.release()
def Log(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
self._log_lock.acquire()
try:
self.log.append((time.time(), log_type, log_msg))
finally:
self._log_lock.release()
def RetrieveLog(self, start_at=0):
"""Retrieve (a part of) the execution log.
"""
self._log_lock.acquire()
try:
return self.log[start_at:]
finally:
self._log_lock.release()
class _QueuedJob(object):
"""In-memory job representation.
This is what we use to track the user-submitted jobs.
"""
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
@classmethod
def Restore(cls, queue, state):
obj = _QueuedJob.__new__(cls)
obj.queue = queue
obj.id = state["id"]
obj.ops = [_QueuedOpCode.Restore(op_state) for op_state in state["ops"]]
obj.run_op_index = state["run_op_index"]
return obj
def Serialize(self):
return {
"id": self.id,
"ops": [op.Serialize() for op in self.ops],
"run_op_index": self.run_op_index,
}
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_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
class _JobQueueWorker(workerpool.BaseWorker):
def RunTask(self, job):
"""Job executor.
This functions processes a job.
"""
logging.debug("Worker %s processing job %s",
self.worker_id, job.id)
proc = mcpu.Processor(self.pool.context)
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_RUNNING
op.result = None
queue.UpdateJobUnlocked(job)
input_opcode = op.input
finally:
queue.release()
result = proc.ExecOpCode(input_opcode, op.Log)
queue.acquire()
try:
op.status = constants.OP_STATUS_SUCCESS
op.result = result
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)
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:
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, context):
super(_JobQueueWorkerPool, self).__init__(JOBQUEUE_THREADS,
_JobQueueWorker)
self.context = context
class JobQueue(object):
_RE_JOB_FILE = re.compile(r"^job-(%s)$" % constants.JOB_ID_TEMPLATE)
def __init__(self, context):
self._memcache = {}
self._my_hostname = utils.HostInfo().name
# Locking
self._lock = threading.Lock()
self.acquire = self._lock.acquire
self.release = self._lock.release
# Make sure our directories exists
for path in (constants.QUEUE_DIR, constants.JOB_QUEUE_ARCHIVE_DIR):
try:
os.mkdir(path, 0700)
except OSError, err:
if err.errno not in (errno.EEXIST, ):
raise
# Get queue lock
self.lock_fd = open(constants.JOB_QUEUE_LOCK_FILE, "w")
try:
utils.LockFile(self.lock_fd)
except:
self.lock_fd.close()
raise
# Read version
try:
version_fd = open(constants.JOB_QUEUE_VERSION_FILE, "r")
except IOError, err:
if err.errno not in (errno.ENOENT, ):
raise
# Setup a new queue
self._InitQueueUnlocked()
# Try to open again
version_fd = open(constants.JOB_QUEUE_VERSION_FILE, "r")
try:
# Try to read version
version = int(version_fd.read(128))
# Verify version
if version != constants.JOB_QUEUE_VERSION:
raise errors.JobQueueError("Found version %s, expected %s",
version, constants.JOB_QUEUE_VERSION)
finally:
version_fd.close()
self._last_serial = self._ReadSerial()
if self._last_serial is None:
raise errors.ConfigurationError("Can't read/parse the job queue serial"
" file")
# Setup worker pool
self._wpool = _JobQueueWorkerPool(context)
# 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, ):
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()
@staticmethod
def _ReadSerial():
"""Try to read the job serial file.
@rtype: None or int
@return: If the serial can be read, then it is returned. Otherwise None
is returned.
"""
try:
serial_fd = open(constants.JOB_QUEUE_SERIAL_FILE, "r")
try:
# Read last serial
serial = int(serial_fd.read(1024).strip())
finally:
serial_fd.close()
except (ValueError, EnvironmentError):
serial = None
return serial
def _InitQueueUnlocked(self):
assert self.lock_fd, "Queue should be open"
utils.WriteFile(constants.JOB_QUEUE_VERSION_FILE,
data="%s\n" % constants.JOB_QUEUE_VERSION)
if self._ReadSerial() is None:
utils.WriteFile(constants.JOB_QUEUE_SERIAL_FILE,
data="%s\n" % 0)
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, nodes):
"""Generates a new job identifier.
Job identifiers are unique during the lifetime of a cluster.
Returns: A string representing the job identifier.
"""
assert self.lock_fd, "Queue should be open"
# New number
serial = self._last_serial + 1
# Write to file
utils.WriteFile(constants.JOB_QUEUE_SERIAL_FILE,
data="%s\n" % serial)
# Keep it only if we were able to write the file
self._last_serial = serial
# Distribute the serial to the other nodes
try:
nodes.remove(self._my_hostname)
except ValueError:
pass
result = rpc.call_upload_file(nodes, constants.JOB_QUEUE_SERIAL_FILE)
for node in nodes:
if not result[node]:
logging.error("copy of job queue file to node %s failed", node)
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.sort()
return jlist
def _ListJobFiles(self):
assert self.lock_fd, "Queue should be open"
return [name for name in utils.ListVisibleFiles(constants.QUEUE_DIR)
if self._RE_JOB_FILE.match(name)]
def _LoadJobUnlocked(self, job_id):
assert self.lock_fd, "Queue should be open"
if job_id in self._memcache:
logging.debug("Found job %s in memcache", job_id)
return self._memcache[job_id]
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
def SubmitJob(self, ops, nodes):
"""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.
@type nodes: list
@param nodes: The list of nodes to which the new job serial will be
distributed.
"""
assert self.lock_fd, "Queue should be open"
# Get job identifier
job_id = self._NewSerialUnlocked(nodes)
job = _QueuedJob(self, job_id, ops)
# Write to disk
self.UpdateJobUnlocked(job)
logging.debug("Added new job %s to the cache", job_id)
self._memcache[job_id] = job
# Add to worker pool
self._wpool.AddTask(job)
return job.id
def UpdateJobUnlocked(self, job):
assert self.lock_fd, "Queue should be open"
filename = self._GetJobPath(job.id)
logging.debug("Writing job %s to %s", job.id, filename)
utils.WriteFile(filename,
data=serializer.DumpJson(job.Serialize(), indent=False))
self._CleanCacheUnlocked([job.id])
def _CleanCacheUnlocked(self, exclude):
"""Clean the memory cache.
The exceptions argument contains job IDs that should not be
cleaned.
"""
assert isinstance(exclude, list)
for job in self._memcache.values():
if job.id in exclude:
continue
if job.CalcStatus() not in (constants.JOB_STATUS_QUEUED,
constants.JOB_STATUS_RUNNING):
logging.debug("Cleaning job %s from the cache", job.id)
try:
del self._memcache[job.id]
except KeyError:
pass
@utils.LockedMethod
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)
@utils.LockedMethod
def ArchiveJob(self, job_id):
"""Archives a job.
@type job_id: string
@param job_id: Job ID of job to be archived.
"""
logging.debug("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
try:
old = self._GetJobPath(job.id)
new = self._GetArchivedJobPath(job.id)
os.rename(old, new)
logging.debug("Successfully archived job %s", job.id)
finally:
# Cleaning the cache because we don't know what os.rename actually did
# and to be on the safe side.
self._CleanCacheUnlocked([])
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 == "ticker":
ji = job.run_op_index
if ji < 0:
lmsg = None
else:
lmsg = job.ops[ji].RetrieveLog(-1)
# message might be empty here
if lmsg:
lmsg = lmsg[0]
else:
lmsg = None
row.append(lmsg)
else:
raise errors.OpExecError("Invalid job query field '%s'" % fname)
return row
@utils.LockedMethod
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
def Shutdown(self):
"""Stops the job queue.
"""
assert self.lock_fd, "Queue should be open"
self._wpool.TerminateWorkers()
self.lock_fd.close()
self.lock_fd = None