f1bd24fbe4
Depends-On: I442249783da4a6ae10c78b95e0b279409c95d2e6 Change-Id: I877928c858e8d6176d3f01ad9de2765104acf5c3
827 lines
33 KiB
Python
827 lines
33 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright (C) 2013 Yahoo! Inc. All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import collections
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import contextlib
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import functools
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import sys
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import threading
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from concurrent import futures
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import fasteners
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from kazoo import exceptions as k_exceptions
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from kazoo.protocol import paths as k_paths
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from kazoo.recipe import watchers
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from oslo_serialization import jsonutils
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from oslo_utils import excutils
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from oslo_utils import uuidutils
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import six
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from taskflow import exceptions as excp
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from taskflow.jobs import base
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from taskflow import logging
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from taskflow import states
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from taskflow.types import timing as tt
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from taskflow.utils import kazoo_utils
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from taskflow.utils import misc
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LOG = logging.getLogger(__name__)
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def check_who(meth):
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"""Decorator that checks the expected owner type & value restrictions."""
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@six.wraps(meth)
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def wrapper(self, job, who, *args, **kwargs):
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if not isinstance(who, six.string_types):
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raise TypeError("Job applicant must be a string type")
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if len(who) == 0:
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raise ValueError("Job applicant must be non-empty")
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return meth(self, job, who, *args, **kwargs)
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return wrapper
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class ZookeeperJob(base.Job):
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"""A zookeeper job."""
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def __init__(self, name, board, client, backend, path,
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uuid=None, details=None, book=None, book_data=None,
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created_on=None):
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super(ZookeeperJob, self).__init__(name, uuid=uuid, details=details)
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self._board = board
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self._book = book
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if not book_data:
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book_data = {}
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self._book_data = book_data
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self._client = client
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self._backend = backend
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if all((self._book, self._book_data)):
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raise ValueError("Only one of 'book_data' or 'book'"
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" can be provided")
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self._path = k_paths.normpath(path)
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self._lock_path = self._path + board.LOCK_POSTFIX
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self._created_on = created_on
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self._node_not_found = False
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basename = k_paths.basename(self._path)
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self._root = self._path[0:-len(basename)]
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self._sequence = int(basename[len(board.JOB_PREFIX):])
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@property
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def lock_path(self):
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return self._lock_path
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@property
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def path(self):
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return self._path
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@property
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def sequence(self):
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"""Sequence number of the current job."""
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return self._sequence
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@property
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def root(self):
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"""The parent path of the job in zookeeper."""
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return self._root
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def _get_node_attr(self, path, attr_name, trans_func=None):
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try:
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_data, node_stat = self._client.get(path)
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attr = getattr(node_stat, attr_name)
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if trans_func is not None:
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return trans_func(attr)
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else:
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return attr
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except k_exceptions.NoNodeError:
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excp.raise_with_cause(
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excp.NotFound,
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"Can not fetch the %r attribute of job %s (%s),"
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" path %s not found" % (attr_name, self.uuid,
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self.path, path))
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except self._client.handler.timeout_exception:
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excp.raise_with_cause(
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excp.JobFailure,
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"Can not fetch the %r attribute of job %s (%s),"
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" operation timed out" % (attr_name, self.uuid, self.path))
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except k_exceptions.SessionExpiredError:
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excp.raise_with_cause(
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excp.JobFailure,
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"Can not fetch the %r attribute of job %s (%s),"
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" session expired" % (attr_name, self.uuid, self.path))
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except (AttributeError, k_exceptions.KazooException):
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excp.raise_with_cause(
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excp.JobFailure,
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"Can not fetch the %r attribute of job %s (%s),"
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" internal error" % (attr_name, self.uuid, self.path))
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@property
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def last_modified(self):
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modified_on = None
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try:
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if not self._node_not_found:
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modified_on = self._get_node_attr(
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self.path, 'mtime',
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trans_func=misc.millis_to_datetime)
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except excp.NotFound:
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self._node_not_found = True
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return modified_on
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@property
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def created_on(self):
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# This one we can cache (since it won't change after creation).
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if self._node_not_found:
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return None
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if self._created_on is None:
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try:
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self._created_on = self._get_node_attr(
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self.path, 'ctime',
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trans_func=misc.millis_to_datetime)
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except excp.NotFound:
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self._node_not_found = True
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return self._created_on
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@property
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def board(self):
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return self._board
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def _load_book(self):
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book_uuid = self.book_uuid
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if self._backend is not None and book_uuid is not None:
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# TODO(harlowja): we are currently limited by assuming that the
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# job posted has the same backend as this loader (to start this
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# seems to be a ok assumption, and can be adjusted in the future
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# if we determine there is a use-case for multi-backend loaders,
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# aka a registry of loaders).
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with contextlib.closing(self._backend.get_connection()) as conn:
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return conn.get_logbook(book_uuid)
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# No backend to fetch from or no uuid specified
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return None
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@property
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def state(self):
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return self._fetch_state()
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def _fetch_state(self):
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owner = self.board.find_owner(self)
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job_data = {}
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try:
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raw_data, _data_stat = self._client.get(self.path)
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job_data = misc.decode_json(raw_data)
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except k_exceptions.NoNodeError:
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pass
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except k_exceptions.SessionExpiredError:
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excp.raise_with_cause(
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excp.JobFailure,
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"Can not fetch the state of %s,"
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" session expired" % (self.uuid))
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except self._client.handler.timeout_exception:
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excp.raise_with_cause(
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excp.JobFailure,
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"Can not fetch the state of %s,"
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" operation timed out" % (self.uuid))
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except k_exceptions.KazooException:
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excp.raise_with_cause(
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excp.JobFailure,
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"Can not fetch the state of %s,"
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" internal error" % (self.uuid))
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if not job_data:
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# No data this job has been completed (the owner that we might have
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# fetched will not be able to be fetched again, since the job node
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# is a parent node of the owner/lock node).
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return states.COMPLETE
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if not owner:
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# No owner, but data, still work to be done.
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return states.UNCLAIMED
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return states.CLAIMED
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def __lt__(self, other):
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if self.root == other.root:
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return self.sequence < other.sequence
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else:
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return self.root < other.root
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def __hash__(self):
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return hash(self.path)
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@property
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def book(self):
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if self._book is None:
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self._book = self._load_book()
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return self._book
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@property
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def book_uuid(self):
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if self._book:
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return self._book.uuid
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if self._book_data:
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return self._book_data.get('uuid')
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else:
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return None
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@property
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def book_name(self):
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if self._book:
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return self._book.name
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if self._book_data:
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return self._book_data.get('name')
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else:
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return None
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class ZookeeperJobBoardIterator(six.Iterator):
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"""Iterator over a zookeeper jobboard that iterates over potential jobs.
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It supports the following attributes/constructor arguments:
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* ``ensure_fresh``: boolean that requests that during every fetch of a new
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set of jobs this will cause the iterator to force the backend to
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refresh (ensuring that the jobboard has the most recent job listings).
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* ``only_unclaimed``: boolean that indicates whether to only iterate
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over unclaimed jobs.
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"""
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_UNCLAIMED_JOB_STATES = (
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states.UNCLAIMED,
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)
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_JOB_STATES = (
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states.UNCLAIMED,
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states.COMPLETE,
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states.CLAIMED,
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)
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def __init__(self, board, only_unclaimed=False, ensure_fresh=False):
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self._board = board
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self._jobs = collections.deque()
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self._fetched = False
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self.ensure_fresh = ensure_fresh
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self.only_unclaimed = only_unclaimed
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@property
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def board(self):
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return self._board
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def __iter__(self):
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return self
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def _next_job(self):
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if self.only_unclaimed:
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allowed_states = self._UNCLAIMED_JOB_STATES
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else:
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allowed_states = self._JOB_STATES
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job = None
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while self._jobs and job is None:
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maybe_job = self._jobs.popleft()
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try:
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if maybe_job.state in allowed_states:
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job = maybe_job
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except excp.JobFailure:
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LOG.warn("Failed determining the state of job: %s (%s)",
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maybe_job.uuid, maybe_job.path, exc_info=True)
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except excp.NotFound:
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self._board._remove_job(maybe_job.path)
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return job
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def __next__(self):
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if not self._jobs:
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if not self._fetched:
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jobs = self._board._fetch_jobs(ensure_fresh=self.ensure_fresh)
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self._jobs.extend(jobs)
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self._fetched = True
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job = self._next_job()
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if job is None:
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raise StopIteration
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else:
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return job
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class ZookeeperJobBoard(base.NotifyingJobBoard):
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"""A jobboard backend by zookeeper.
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Powered by the `kazoo <http://kazoo.readthedocs.org/>`_ library.
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This jobboard creates *sequenced* persistent znodes in a directory in
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zookeeper (that directory defaults to ``/taskflow/jobs``) and uses
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zookeeper watches to notify other jobboards that the job which was posted
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using the :meth:`.post` method (this creates a znode with contents/details
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in json). The users of those jobboard(s) (potentially on disjoint sets of
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machines) can then iterate over the available jobs and decide if they want
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to attempt to claim one of the jobs they have iterated over. If so they
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will then attempt to contact zookeeper and they will attempt to create a
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ephemeral znode using the name of the persistent znode + ".lock" as a
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postfix. If the entity trying to use the jobboard to :meth:`.claim` the
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job is able to create a ephemeral znode with that name then it will be
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allowed (and expected) to perform whatever *work* the contents of that
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job described. Once finished the ephemeral znode and persistent znode may
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be deleted (if successfully completed) in a single transaction or if not
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successful (or the entity that claimed the znode dies) the ephemeral
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znode will be released (either manually by using :meth:`.abandon` or
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automatically by zookeeper when the ephemeral node and associated session
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is deemed to have been lost).
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"""
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#: Transaction support was added in 3.4.0 so we need at least that version.
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MIN_ZK_VERSION = (3, 4, 0)
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#: Znode **postfix** that lock entries have.
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LOCK_POSTFIX = ".lock"
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#: Znode child path created under root path that contains trashed jobs.
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TRASH_FOLDER = ".trash"
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#: Znode **prefix** that job entries have.
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JOB_PREFIX = 'job'
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#: Default znode path used for jobs (data, locks...).
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DEFAULT_PATH = "/taskflow/jobs"
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def __init__(self, name, conf,
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client=None, persistence=None, emit_notifications=True):
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super(ZookeeperJobBoard, self).__init__(name, conf)
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if client is not None:
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self._client = client
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self._owned = False
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else:
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self._client = kazoo_utils.make_client(self._conf)
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self._owned = True
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path = str(conf.get("path", self.DEFAULT_PATH))
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if not path:
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raise ValueError("Empty zookeeper path is disallowed")
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if not k_paths.isabs(path):
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raise ValueError("Zookeeper path must be absolute")
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self._path = path
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self._trash_path = self._path.replace(k_paths.basename(self._path),
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self.TRASH_FOLDER)
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# The backend to load the full logbooks from, since whats sent over
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# the zookeeper data connection is only the logbook uuid and name, and
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# not currently the full logbook (later when a zookeeper backend
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# appears we can likely optimize for that backend usage by directly
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# reading from the path where the data is stored, if we want).
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self._persistence = persistence
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# Misc. internal details
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self._known_jobs = {}
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self._job_cond = threading.Condition()
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self._open_close_lock = threading.RLock()
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self._client.add_listener(self._state_change_listener)
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self._bad_paths = frozenset([path])
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self._job_watcher = None
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# Since we use sequenced ids this will be the path that the sequences
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# are prefixed with, for example, job0000000001, job0000000002, ...
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self._job_base = k_paths.join(path, self.JOB_PREFIX)
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self._worker = None
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self._emit_notifications = bool(emit_notifications)
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self._connected = False
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def _emit(self, state, details):
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# Submit the work to the executor to avoid blocking the kazoo threads
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# and queue(s)...
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worker = self._worker
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if worker is None:
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return
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try:
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worker.submit(self.notifier.notify, state, details)
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except RuntimeError:
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# Notification thread is shutdown just skip submitting a
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# notification...
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pass
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@property
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def path(self):
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return self._path
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@property
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def trash_path(self):
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return self._trash_path
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@property
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def job_count(self):
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return len(self._known_jobs)
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def _fetch_jobs(self, ensure_fresh=False):
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if ensure_fresh:
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self._force_refresh()
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with self._job_cond:
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return sorted(six.itervalues(self._known_jobs))
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def _force_refresh(self):
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try:
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children = self._client.get_children(self.path)
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except self._client.handler.timeout_exception:
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excp.raise_with_cause(excp.JobFailure,
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"Refreshing failure, operation timed out")
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except k_exceptions.SessionExpiredError:
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excp.raise_with_cause(excp.JobFailure,
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"Refreshing failure, session expired")
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except k_exceptions.NoNodeError:
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pass
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except k_exceptions.KazooException:
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excp.raise_with_cause(excp.JobFailure,
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"Refreshing failure, internal error")
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else:
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self._on_job_posting(children, delayed=False)
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def iterjobs(self, only_unclaimed=False, ensure_fresh=False):
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return ZookeeperJobBoardIterator(self,
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only_unclaimed=only_unclaimed,
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ensure_fresh=ensure_fresh)
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def _remove_job(self, path):
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if path not in self._known_jobs:
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return
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with self._job_cond:
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job = self._known_jobs.pop(path, None)
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if job is not None:
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LOG.debug("Removed job that was at path '%s'", path)
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self._emit(base.REMOVAL, details={'job': job})
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def _process_child(self, path, request):
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"""Receives the result of a child data fetch request."""
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job = None
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try:
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raw_data, node_stat = request.get()
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job_data = misc.decode_json(raw_data)
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created_on = misc.millis_to_datetime(node_stat.ctime)
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except (ValueError, TypeError, KeyError):
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LOG.warn("Incorrectly formatted job data found at path: %s",
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path, exc_info=True)
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except self._client.handler.timeout_exception:
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LOG.warn("Operation timed out fetching job data from path: %s",
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path, exc_info=True)
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except k_exceptions.SessionExpiredError:
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LOG.warn("Session expired fetching job data from path: %s", path,
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exc_info=True)
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except k_exceptions.NoNodeError:
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LOG.debug("No job node found at path: %s, it must have"
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" disappeared or was removed", path)
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except k_exceptions.KazooException:
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LOG.warn("Internal error fetching job data from path: %s",
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path, exc_info=True)
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else:
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with self._job_cond:
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# Now we can offically check if someone already placed this
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# jobs information into the known job set (if it's already
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# existing then just leave it alone).
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if path not in self._known_jobs:
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job = ZookeeperJob(job_data['name'], self,
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self._client, self._persistence, path,
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uuid=job_data['uuid'],
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book_data=job_data.get("book"),
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details=job_data.get("details", {}),
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created_on=created_on)
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self._known_jobs[path] = job
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self._job_cond.notify_all()
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if job is not None:
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self._emit(base.POSTED, details={'job': job})
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def _on_job_posting(self, children, delayed=True):
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LOG.debug("Got children %s under path %s", children, self.path)
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child_paths = []
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for c in children:
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if (c.endswith(self.LOCK_POSTFIX) or
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not c.startswith(self.JOB_PREFIX)):
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# Skip lock paths or non-job-paths (these are not valid jobs)
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continue
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child_paths.append(k_paths.join(self.path, c))
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# Figure out what we really should be investigating and what we
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# shouldn't (remove jobs that exist in our local version, but don't
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# exist in the children anymore) and accumulate all paths that we
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|
# need to trigger population of (without holding the job lock).
|
|
investigate_paths = []
|
|
pending_removals = []
|
|
with self._job_cond:
|
|
for path in six.iterkeys(self._known_jobs):
|
|
if path not in child_paths:
|
|
pending_removals.append(path)
|
|
for path in child_paths:
|
|
if path in self._bad_paths:
|
|
continue
|
|
# This pre-check will *not* guarantee that we will not already
|
|
# have the job (if it's being populated elsewhere) but it will
|
|
# reduce the amount of duplicated requests in general; later when
|
|
# the job information has been populated we will ensure that we
|
|
# are not adding duplicates into the currently known jobs...
|
|
if path in self._known_jobs:
|
|
continue
|
|
if path not in investigate_paths:
|
|
investigate_paths.append(path)
|
|
if pending_removals:
|
|
with self._job_cond:
|
|
for path in pending_removals:
|
|
self._remove_job(path)
|
|
for path in investigate_paths:
|
|
# Fire off the request to populate this job.
|
|
#
|
|
# This method is *usually* called from a asynchronous handler so
|
|
# it's better to exit from this quickly to allow other asynchronous
|
|
# handlers to be executed.
|
|
request = self._client.get_async(path)
|
|
if delayed:
|
|
request.rawlink(functools.partial(self._process_child, path))
|
|
else:
|
|
self._process_child(path, request)
|
|
|
|
def post(self, name, book=None, details=None):
|
|
|
|
def format_posting(job_uuid):
|
|
posting = {
|
|
'uuid': job_uuid,
|
|
'name': name,
|
|
}
|
|
if details:
|
|
posting['details'] = details
|
|
else:
|
|
posting['details'] = {}
|
|
if book is not None:
|
|
posting['book'] = {
|
|
'name': book.name,
|
|
'uuid': book.uuid,
|
|
}
|
|
return posting
|
|
|
|
# NOTE(harlowja): Jobs are not ephemeral, they will persist until they
|
|
# are consumed (this may change later, but seems safer to do this until
|
|
# further notice).
|
|
job_uuid = uuidutils.generate_uuid()
|
|
with self._wrap(job_uuid, None,
|
|
"Posting failure: %s", ensure_known=False):
|
|
job_posting = format_posting(job_uuid)
|
|
job_posting = misc.binary_encode(jsonutils.dumps(job_posting))
|
|
job_path = self._client.create(self._job_base,
|
|
value=job_posting,
|
|
sequence=True,
|
|
ephemeral=False)
|
|
job = ZookeeperJob(name, self, self._client,
|
|
self._persistence, job_path,
|
|
book=book, details=details,
|
|
uuid=job_uuid)
|
|
with self._job_cond:
|
|
self._known_jobs[job_path] = job
|
|
self._job_cond.notify_all()
|
|
self._emit(base.POSTED, details={'job': job})
|
|
return job
|
|
|
|
@check_who
|
|
def claim(self, job, who):
|
|
def _unclaimable_try_find_owner(cause):
|
|
try:
|
|
owner = self.find_owner(job)
|
|
except Exception:
|
|
owner = None
|
|
if owner:
|
|
message = "Job %s already claimed by '%s'" % (job.uuid, owner)
|
|
else:
|
|
message = "Job %s already claimed" % (job.uuid)
|
|
excp.raise_with_cause(excp.UnclaimableJob,
|
|
message, cause=cause)
|
|
|
|
with self._wrap(job.uuid, job.path, "Claiming failure: %s"):
|
|
# NOTE(harlowja): post as json which will allow for future changes
|
|
# more easily than a raw string/text.
|
|
value = jsonutils.dumps({
|
|
'owner': who,
|
|
})
|
|
# Ensure the target job is still existent (at the right version).
|
|
job_data, job_stat = self._client.get(job.path)
|
|
txn = self._client.transaction()
|
|
# This will abort (and not create the lock) if the job has been
|
|
# removed (somehow...) or updated by someone else to a different
|
|
# version...
|
|
txn.check(job.path, version=job_stat.version)
|
|
txn.create(job.lock_path, value=misc.binary_encode(value),
|
|
ephemeral=True)
|
|
try:
|
|
kazoo_utils.checked_commit(txn)
|
|
except k_exceptions.NodeExistsError as e:
|
|
_unclaimable_try_find_owner(e)
|
|
except kazoo_utils.KazooTransactionException as e:
|
|
if len(e.failures) < 2:
|
|
raise
|
|
else:
|
|
if isinstance(e.failures[0], k_exceptions.NoNodeError):
|
|
excp.raise_with_cause(
|
|
excp.NotFound,
|
|
"Job %s not found to be claimed" % job.uuid,
|
|
cause=e.failures[0])
|
|
if isinstance(e.failures[1], k_exceptions.NodeExistsError):
|
|
_unclaimable_try_find_owner(e.failures[1])
|
|
else:
|
|
excp.raise_with_cause(
|
|
excp.UnclaimableJob,
|
|
"Job %s claim failed due to transaction"
|
|
" not succeeding" % (job.uuid), cause=e)
|
|
|
|
@contextlib.contextmanager
|
|
def _wrap(self, job_uuid, job_path,
|
|
fail_msg_tpl="Failure: %s", ensure_known=True):
|
|
if job_path:
|
|
fail_msg_tpl += " (%s)" % (job_path)
|
|
if ensure_known:
|
|
if not job_path:
|
|
raise ValueError("Unable to check if %r is a known path"
|
|
% (job_path))
|
|
if job_path not in self._known_jobs:
|
|
fail_msg_tpl += ", unknown job"
|
|
raise excp.NotFound(fail_msg_tpl % (job_uuid))
|
|
try:
|
|
yield
|
|
except self._client.handler.timeout_exception:
|
|
fail_msg_tpl += ", operation timed out"
|
|
excp.raise_with_cause(excp.JobFailure, fail_msg_tpl % (job_uuid))
|
|
except k_exceptions.SessionExpiredError:
|
|
fail_msg_tpl += ", session expired"
|
|
excp.raise_with_cause(excp.JobFailure, fail_msg_tpl % (job_uuid))
|
|
except k_exceptions.NoNodeError:
|
|
fail_msg_tpl += ", unknown job"
|
|
excp.raise_with_cause(excp.NotFound, fail_msg_tpl % (job_uuid))
|
|
except k_exceptions.KazooException:
|
|
fail_msg_tpl += ", internal error"
|
|
excp.raise_with_cause(excp.JobFailure, fail_msg_tpl % (job_uuid))
|
|
|
|
def find_owner(self, job):
|
|
with self._wrap(job.uuid, job.path, "Owner query failure: %s"):
|
|
try:
|
|
self._client.sync(job.lock_path)
|
|
raw_data, _lock_stat = self._client.get(job.lock_path)
|
|
data = misc.decode_json(raw_data)
|
|
owner = data.get("owner")
|
|
except k_exceptions.NoNodeError:
|
|
owner = None
|
|
return owner
|
|
|
|
def _get_owner_and_data(self, job):
|
|
lock_data, lock_stat = self._client.get(job.lock_path)
|
|
job_data, job_stat = self._client.get(job.path)
|
|
return (misc.decode_json(lock_data), lock_stat,
|
|
misc.decode_json(job_data), job_stat)
|
|
|
|
@check_who
|
|
def consume(self, job, who):
|
|
with self._wrap(job.uuid, job.path, "Consumption failure: %s"):
|
|
try:
|
|
owner_data = self._get_owner_and_data(job)
|
|
lock_data, lock_stat, data, data_stat = owner_data
|
|
except k_exceptions.NoNodeError:
|
|
excp.raise_with_cause(excp.JobFailure,
|
|
"Can not consume a job %s"
|
|
" which we can not determine"
|
|
" the owner of" % (job.uuid))
|
|
if lock_data.get("owner") != who:
|
|
raise excp.JobFailure("Can not consume a job %s"
|
|
" which is not owned by %s"
|
|
% (job.uuid, who))
|
|
txn = self._client.transaction()
|
|
txn.delete(job.lock_path, version=lock_stat.version)
|
|
txn.delete(job.path, version=data_stat.version)
|
|
kazoo_utils.checked_commit(txn)
|
|
self._remove_job(job.path)
|
|
|
|
@check_who
|
|
def abandon(self, job, who):
|
|
with self._wrap(job.uuid, job.path, "Abandonment failure: %s"):
|
|
try:
|
|
owner_data = self._get_owner_and_data(job)
|
|
lock_data, lock_stat, data, data_stat = owner_data
|
|
except k_exceptions.NoNodeError:
|
|
excp.raise_with_cause(excp.JobFailure,
|
|
"Can not abandon a job %s"
|
|
" which we can not determine"
|
|
" the owner of" % (job.uuid))
|
|
if lock_data.get("owner") != who:
|
|
raise excp.JobFailure("Can not abandon a job %s"
|
|
" which is not owned by %s"
|
|
% (job.uuid, who))
|
|
txn = self._client.transaction()
|
|
txn.delete(job.lock_path, version=lock_stat.version)
|
|
kazoo_utils.checked_commit(txn)
|
|
|
|
@check_who
|
|
def trash(self, job, who):
|
|
with self._wrap(job.uuid, job.path, "Trash failure: %s"):
|
|
try:
|
|
owner_data = self._get_owner_and_data(job)
|
|
lock_data, lock_stat, data, data_stat = owner_data
|
|
except k_exceptions.NoNodeError:
|
|
excp.raise_with_cause(excp.JobFailure,
|
|
"Can not trash a job %s"
|
|
" which we can not determine"
|
|
" the owner of" % (job.uuid))
|
|
if lock_data.get("owner") != who:
|
|
raise excp.JobFailure("Can not trash a job %s"
|
|
" which is not owned by %s"
|
|
% (job.uuid, who))
|
|
trash_path = job.path.replace(self.path, self.trash_path)
|
|
value = misc.binary_encode(jsonutils.dumps(data))
|
|
txn = self._client.transaction()
|
|
txn.create(trash_path, value=value)
|
|
txn.delete(job.lock_path, version=lock_stat.version)
|
|
txn.delete(job.path, version=data_stat.version)
|
|
kazoo_utils.checked_commit(txn)
|
|
|
|
def _state_change_listener(self, state):
|
|
LOG.debug("Kazoo client has changed to state: %s", state)
|
|
|
|
def wait(self, timeout=None):
|
|
# Wait until timeout expires (or forever) for jobs to appear.
|
|
watch = tt.StopWatch(duration=timeout)
|
|
watch.start()
|
|
with self._job_cond:
|
|
while True:
|
|
if not self._known_jobs:
|
|
if watch.expired():
|
|
raise excp.NotFound("Expired waiting for jobs to"
|
|
" arrive; waited %s seconds"
|
|
% watch.elapsed())
|
|
# This is done since the given timeout can not be provided
|
|
# to the condition variable, since we can not ensure that
|
|
# when we acquire the condition that there will actually
|
|
# be jobs (especially if we are spuriously awaken), so we
|
|
# must recalculate the amount of time we really have left.
|
|
self._job_cond.wait(watch.leftover(return_none=True))
|
|
else:
|
|
it = ZookeeperJobBoardIterator(self)
|
|
it._jobs.extend(self._fetch_jobs())
|
|
it._fetched = True
|
|
return it
|
|
|
|
@property
|
|
def connected(self):
|
|
return self._connected and self._client.connected
|
|
|
|
@fasteners.locked(lock='_open_close_lock')
|
|
def close(self):
|
|
if self._owned:
|
|
LOG.debug("Stopping client")
|
|
kazoo_utils.finalize_client(self._client)
|
|
if self._worker is not None:
|
|
LOG.debug("Shutting down the notifier")
|
|
self._worker.shutdown()
|
|
self._worker = None
|
|
with self._job_cond:
|
|
self._known_jobs.clear()
|
|
LOG.debug("Stopped & cleared local state")
|
|
self._connected = False
|
|
|
|
@fasteners.locked(lock='_open_close_lock')
|
|
def connect(self, timeout=10.0):
|
|
|
|
def try_clean():
|
|
# Attempt to do the needed cleanup if post-connection setup does
|
|
# not succeed (maybe the connection is lost right after it is
|
|
# obtained).
|
|
try:
|
|
self.close()
|
|
except k_exceptions.KazooException:
|
|
LOG.exception("Failed cleaning-up after post-connection"
|
|
" initialization failed")
|
|
|
|
try:
|
|
if timeout is not None:
|
|
timeout = float(timeout)
|
|
self._client.start(timeout=timeout)
|
|
except (self._client.handler.timeout_exception,
|
|
k_exceptions.KazooException):
|
|
excp.raise_with_cause(excp.JobFailure,
|
|
"Failed to connect to zookeeper")
|
|
try:
|
|
if self._conf.get('check_compatible', True):
|
|
kazoo_utils.check_compatible(self._client, self.MIN_ZK_VERSION)
|
|
if self._worker is None and self._emit_notifications:
|
|
self._worker = futures.ThreadPoolExecutor(max_workers=1)
|
|
self._client.ensure_path(self.path)
|
|
self._client.ensure_path(self.trash_path)
|
|
if self._job_watcher is None:
|
|
self._job_watcher = watchers.ChildrenWatch(
|
|
self._client,
|
|
self.path,
|
|
func=self._on_job_posting,
|
|
allow_session_lost=True)
|
|
self._connected = True
|
|
except excp.IncompatibleVersion:
|
|
with excutils.save_and_reraise_exception():
|
|
try_clean()
|
|
except (self._client.handler.timeout_exception,
|
|
k_exceptions.KazooException):
|
|
exc_type, exc, exc_tb = sys.exc_info()
|
|
try:
|
|
try_clean()
|
|
excp.raise_with_cause(excp.JobFailure,
|
|
"Failed to do post-connection"
|
|
" initialization", cause=exc)
|
|
finally:
|
|
del(exc_type, exc, exc_tb)
|