Source code for gear

# Copyright 2013 OpenStack Foundation
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

import logging
import os
import select
import socket
import ssl
import struct
import threading
import time
import uuid as uuid_module

from gear import constants

try:
    import Queue as queue
except ImportError:
    import queue as queue

PRECEDENCE_NORMAL = 0
PRECEDENCE_LOW = 1
PRECEDENCE_HIGH = 2


[docs]class ConnectionError(Exception): pass
[docs]class InvalidDataError(Exception): pass
[docs]class ConfigurationError(Exception): pass
[docs]class NoConnectedServersError(Exception): pass
[docs]class UnknownJobError(Exception): pass
[docs]class InterruptedError(Exception): pass
class TimeoutError(Exception): pass class GearmanError(Exception): pass def convert_to_bytes(data): try: data = data.encode('utf8') except AttributeError: pass return data class Task(object): def __init__(self): self._wait_event = threading.Event() def setComplete(self): self._wait_event.set() def wait(self, timeout=None): """Wait for a response from Gearman. :arg int timeout: If not None, return after this many seconds if no response has been received (default: None). """ self._wait_event.wait(timeout) return self._wait_event.is_set() class SubmitJobTask(Task): def __init__(self, job): super(SubmitJobTask, self).__init__() self.job = job class OptionReqTask(Task): pass
[docs]class Connection(object): """A Connection to a Gearman Server.""" log = logging.getLogger("gear.Connection") def __init__(self, host, port, ssl_key=None, ssl_cert=None, ssl_ca=None): self.host = host self.port = port self.ssl_key = ssl_key self.ssl_cert = ssl_cert self.ssl_ca = ssl_ca self.echo_lock = threading.Lock() self._init() def _init(self): self.conn = None self.connected = False self.connect_time = None self.related_jobs = {} self.pending_tasks = [] self.admin_requests = [] self.echo_conditions = {} self.options = set() self.changeState("INIT") def changeState(self, state): # The state variables are provided as a convenience (and used by # the Worker implementation). They aren't used or modified within # the connection object itself except to reset to "INIT" immediately # after reconnection. self.log.debug("Setting state to: %s" % state) self.state = state self.state_time = time.time() def __repr__(self): return '<gear.Connection 0x%x host: %s port: %s>' % ( id(self), self.host, self.port)
[docs] def connect(self): """Open a connection to the server. :raises ConnectionError: If unable to open the socket. """ self.log.debug("Connecting to %s port %s" % (self.host, self.port)) s = None for res in socket.getaddrinfo(self.host, self.port, socket.AF_UNSPEC, socket.SOCK_STREAM): af, socktype, proto, canonname, sa = res try: s = socket.socket(af, socktype, proto) except socket.error: s = None continue if all([self.ssl_key, self.ssl_cert, self.ssl_ca]): self.log.debug("Using SSL") s = ssl.wrap_socket(s, ssl_version=ssl.PROTOCOL_TLSv1, cert_reqs=ssl.CERT_REQUIRED, keyfile=self.ssl_key, certfile=self.ssl_cert, ca_certs=self.ssl_ca) try: s.connect(sa) except socket.error: s.close() s = None continue break if s is None: self.log.debug("Error connecting to %s port %s" % ( self.host, self.port)) raise ConnectionError("Unable to open socket") self.log.debug("Connected to %s port %s" % (self.host, self.port)) self.conn = s self.connected = True self.connect_time = time.time()
[docs] def disconnect(self): """Disconnect from the server and remove all associated state data. """ if self.conn: try: self.conn.close() except Exception: pass self.log.debug("Disconnected from %s port %s" % (self.host, self.port)) self._init()
[docs] def reconnect(self): """Disconnect from and reconnect to the server, removing all associated state data. """ self.disconnect() self.connect()
[docs] def sendPacket(self, packet): """Send a packet to the server. :arg Packet packet: The :py:class:`Packet` to send. """ self.log.debug("Sending packet: %s" % packet) self.conn.send(packet.toBinary())
def _getAdminRequest(self): return self.admin_requests.pop(0)
[docs] def readPacket(self): """Read one packet or administrative response from the server. Blocks until the complete packet or response is read. :returns: The :py:class:`Packet` or :py:class:`AdminRequest` read. :rtype: :py:class:`Packet` or :py:class:`AdminRequest` """ packet = b'' datalen = 0 code = None ptype = None admin = None admin_request = None while True: c = self.conn.recv(1) if not c: return None if admin is None: if c == b'\x00': admin = False else: admin = True admin_request = self._getAdminRequest() packet += c if admin: if admin_request.isComplete(packet): return admin_request else: if len(packet) == 12: code, ptype, datalen = struct.unpack('!4sii', packet) if len(packet) == datalen + 12: return Packet(code, ptype, packet[12:], connection=self)
[docs] def sendAdminRequest(self, request, timeout=90): """Send an administrative request to the server. :arg AdminRequest request: The :py:class:`AdminRequest` to send. :arg numeric timeout: Number of seconds to wait until the response is received. If None, wait forever (default: 90 seconds). :raises TimeoutError: If the timeout is reached before the response is received. """ self.admin_requests.append(request) self.conn.send(request.getCommand()) complete = request.waitForResponse(timeout) if not complete: raise TimeoutError()
[docs] def echo(self, data=None, timeout=30): """Perform an echo test on the server. This method waits until the echo response has been received or the timeout has been reached. :arg bytes data: The data to request be echoed. If None, a random unique byte string will be generated. :arg numeric timeout: Number of seconds to wait until the response is received. If None, wait forever (default: 30 seconds). :raises TimeoutError: If the timeout is reached before the response is received. """ if data is None: data = uuid_module.uuid4().hex.encode('utf8') self.echo_lock.acquire() try: if data in self.echo_conditions: raise InvalidDataError("This client is already waiting on an " "echo response of: %s" % data) condition = threading.Condition() self.echo_conditions[data] = condition finally: self.echo_lock.release() self.sendEchoReq(data) condition.acquire() condition.wait(timeout) condition.release() if data in self.echo_conditions: return data raise TimeoutError()
def sendEchoReq(self, data): p = Packet(constants.REQ, constants.ECHO_REQ, data) self.sendPacket(p) def handleEchoRes(self, data): condition = None self.echo_lock.acquire() try: condition = self.echo_conditions.get(data) if condition: del self.echo_conditions[data] finally: self.echo_lock.release() if not condition: return False condition.notifyAll() return True def handleOptionRes(self, option): self.options.add(option)
[docs]class AdminRequest(object): """Encapsulates a request (and response) sent over the administrative protocol. This is a base class that may not be instantiated dircectly; a subclass implementing a specific command must be used instead. :arg list arguments: A list of byte string arguments for the command. The following instance attributes are available: **response** (bytes) The response from the server. **arguments** (bytes) The argument supplied with the constructor. **command** (bytes) The administrative command. """ log = logging.getLogger("gear.AdminRequest") command = None arguments = [] response = None def __init__(self, *arguments): self.wait_event = threading.Event() self.arguments = arguments if type(self) == AdminRequest: raise NotImplementedError("AdminRequest must be subclassed") def __repr__(self): return '<gear.AdminRequest 0x%x command: %s>' % ( id(self), self.command) def getCommand(self): cmd = self.command if self.arguments: cmd += b' ' + b' '.join(self.arguments) cmd += b'\n' return cmd def isComplete(self, data): if (data[-3:] == b'\n.\n' or data[-5:] == b'\r\n.\r\n' or data == b'.\n' or data == b'.\r\n'): self.response = data return True return False def setComplete(self): self.wait_event.set() def waitForResponse(self, timeout=None): self.wait_event.wait(timeout) return self.wait_event.is_set()
[docs]class StatusAdminRequest(AdminRequest): """A "status" administrative request. The response from gearman may be found in the **response** attribute. """ command = b'status' def __init__(self): super(StatusAdminRequest, self).__init__()
[docs]class ShowJobsAdminRequest(AdminRequest): """A "show jobs" administrative request. The response from gearman may be found in the **response** attribute. """ command = b'show jobs' def __init__(self): super(ShowJobsAdminRequest, self).__init__()
[docs]class ShowUniqueJobsAdminRequest(AdminRequest): """A "show unique jobs" administrative request. The response from gearman may be found in the **response** attribute. """ command = b'show unique jobs' def __init__(self): super(ShowUniqueJobsAdminRequest, self).__init__()
[docs]class CancelJobAdminRequest(AdminRequest): """A "cancel job" administrative request. :arg str handle: The job handle to be canceled. The response from gearman may be found in the **response** attribute. """ command = b'cancel job' def __init__(self, handle): handle = convert_to_bytes(handle) super(CancelJobAdminRequest, self).__init__(handle) def isComplete(self, data): if data[-1:] == b'\n': self.response = data return True return False
[docs]class VersionAdminRequest(AdminRequest): """A "version" administrative request. The response from gearman may be found in the **response** attribute. """ command = b'version' def __init__(self): super(VersionAdminRequest, self).__init__() def isComplete(self, data): if data[-1:] == b'\n': self.response = data return True return False
class WorkersAdminRequest(AdminRequest): """A "workers" administrative request. The response from gearman may be found in the **response** attribute. """ command = b'workers' def __init__(self): super(WorkersAdminRequest, self).__init__()
[docs]class Packet(object): """A data packet received from or to be sent over a :py:class:`Connection`. :arg bytes code: The Gearman magic code (:py:data:`constants.REQ` or :py:data:`constants.RES`) :arg bytes ptype: The packet type (one of the packet types in constasts). :arg bytes data: The data portion of the packet. :arg Connection connection: The connection on which the packet was received (optional). :raises InvalidDataError: If the magic code is unknown. """ log = logging.getLogger("gear.Packet") def __init__(self, code, ptype, data, connection=None): if not isinstance(code, bytes) and not isinstance(code, bytearray): raise TypeError("code must be of type bytes or bytearray") if code[0:1] != b'\x00': raise InvalidDataError("First byte of packet must be 0") self.code = code self.ptype = ptype if not isinstance(data, bytes) and not isinstance(data, bytearray): raise TypeError("data must be of type bytes or bytearray") self.data = data self.connection = connection def __repr__(self): ptype = constants.types.get(self.ptype, 'UNKNOWN') return '<gear.Packet 0x%x type: %s>' % (id(self), ptype)
[docs] def toBinary(self): """Return a Gearman wire protocol binary representation of the packet. :returns: The packet in binary form. :rtype: bytes """ b = struct.pack('!4sii', self.code, self.ptype, len(self.data)) b = bytearray(b) b += self.data return b
[docs] def getArgument(self, index, last=False): """Get the nth argument from the packet data. :arg int index: The argument index to look up. :arg bool last: Whether this is the last argument (and thus nulls should be ignored) :returns: The argument value. :rtype: bytes """ parts = self.data.split(b'\x00') if not last: return parts[index] return b'\x00'.join(parts[index:])
[docs] def getJob(self): """Get the :py:class:`Job` associated with the job handle in this packet. :returns: The :py:class:`Job` for this packet. :rtype: Job :raises UnknownJobError: If the job is not known. """ handle = self.getArgument(0) job = self.connection.related_jobs.get(handle) if not job: raise UnknownJobError() return job
class BaseClientServer(object): log = logging.getLogger("gear.BaseClientServer") def __init__(self): self.running = True self.active_connections = [] self.inactive_connections = [] self.connection_index = -1 # A lock and notification mechanism to handle not having any # current connections self.connections_condition = threading.Condition() # A pipe to wake up the poll loop in case it needs to restart self.wake_read, self.wake_write = os.pipe() self.poll_thread = threading.Thread(name="Gearman client poll", target=self._doPollLoop) self.poll_thread.daemon = True self.poll_thread.start() self.connect_thread = threading.Thread(name="Gearman client connect", target=self._doConnectLoop) self.connect_thread.daemon = True self.connect_thread.start() def _doConnectLoop(self): # Outer run method of the reconnection thread while self.running: self.connections_condition.acquire() while self.running and not self.inactive_connections: self.log.debug("Waiting for change in available servers " "to reconnect") self.connections_condition.wait() self.connections_condition.release() self.log.debug("Checking if servers need to be reconnected") try: if self.running and not self._connectLoop(): # Nothing happened time.sleep(2) except Exception: self.log.exception("Exception in connect loop:") def _connectLoop(self): # Inner method of the reconnection loop, triggered by # a connection change success = False for conn in self.inactive_connections[:]: self.log.debug("Trying to reconnect %s" % conn) try: conn.reconnect() except ConnectionError: self.log.debug("Unable to connect to %s" % conn) continue except Exception: self.log.exception("Exception while connecting to %s" % conn) continue try: self._onConnect(conn) except Exception: self.log.exception("Exception while performing on-connect " "tasks for %s" % conn) continue self.connections_condition.acquire() self.inactive_connections.remove(conn) self.active_connections.append(conn) self.connections_condition.notifyAll() os.write(self.wake_write, b'1\n') self.connections_condition.release() try: self._onActiveConnection(conn) except Exception: self.log.exception("Exception while performing active conn " "tasks for %s" % conn) success = True return success def _onConnect(self, conn): # Called immediately after a successful (re-)connection pass def _onActiveConnection(self, conn): # Called immediately after a connection is activated pass def _lostConnection(self, conn): # Called as soon as a connection is detected as faulty. Remove # it and return ASAP and let the connection thread deal with it. self.log.debug("Marking %s as disconnected" % conn) self.connections_condition.acquire() jobs = conn.related_jobs.values() self.active_connections.remove(conn) self.inactive_connections.append(conn) self.connections_condition.notifyAll() self.connections_condition.release() for job in jobs: self.handleDisconnect(job) def _doPollLoop(self): # Outer run method of poll thread. while self.running: self.connections_condition.acquire() while self.running and not self.active_connections: self.log.debug("Waiting for change in available connections " "to poll") self.connections_condition.wait() self.connections_condition.release() try: self._pollLoop() except Exception: self.log.exception("Exception in poll loop:") def _pollLoop(self): # Inner method of poll loop self.log.debug("Preparing to poll") poll = select.poll() bitmask = (select.POLLIN | select.POLLERR | select.POLLHUP | select.POLLNVAL) # Reverse mapping of fd -> connection conn_dict = {} for conn in self.active_connections: poll.register(conn.conn.fileno(), bitmask) conn_dict[conn.conn.fileno()] = conn # Register the wake pipe so that we can break if we need to # reconfigure connections poll.register(self.wake_read, bitmask) while self.running: self.log.debug("Polling %s connections" % len(self.active_connections)) ret = poll.poll() for fd, event in ret: if fd == self.wake_read: self.log.debug("Woken by pipe") while True: if os.read(self.wake_read, 1) == b'\n': break return conn = conn_dict[fd] if event & select.POLLIN: self.log.debug("Processing input on %s" % conn) p = conn.readPacket() if p: if isinstance(p, Packet): self.handlePacket(p) else: self.handleAdminRequest(p) else: self.log.debug("Received no data on %s" % conn) self._lostConnection(conn) return else: self.log.debug("Received error event on %s" % conn) self._lostConnection(conn) return def handlePacket(self, packet): """Handle a received packet. This method is called whenever a packet is received from any connection. It normally calls the handle method appropriate for the specific packet. :arg Packet packet: The :py:class:`Packet` that was received. """ self.log.debug("Received packet %s" % packet) if packet.ptype == constants.JOB_CREATED: self.handleJobCreated(packet) elif packet.ptype == constants.WORK_COMPLETE: self.handleWorkComplete(packet) elif packet.ptype == constants.WORK_FAIL: self.handleWorkFail(packet) elif packet.ptype == constants.WORK_EXCEPTION: self.handleWorkException(packet) elif packet.ptype == constants.WORK_DATA: self.handleWorkData(packet) elif packet.ptype == constants.WORK_WARNING: self.handleWorkWarning(packet) elif packet.ptype == constants.WORK_STATUS: self.handleWorkStatus(packet) elif packet.ptype == constants.STATUS_RES: self.handleStatusRes(packet) elif packet.ptype == constants.GET_STATUS: self.handleGetStatus(packet) elif packet.ptype == constants.JOB_ASSIGN_UNIQ: self.handleJobAssignUnique(packet) elif packet.ptype == constants.JOB_ASSIGN: self.handleJobAssign(packet) elif packet.ptype == constants.NO_JOB: self.handleNoJob(packet) elif packet.ptype == constants.NOOP: self.handleNoop(packet) elif packet.ptype == constants.SUBMIT_JOB: self.handleSubmitJob(packet) elif packet.ptype == constants.SUBMIT_JOB_BG: self.handleSubmitJobBg(packet) elif packet.ptype == constants.SUBMIT_JOB_HIGH: self.handleSubmitJobHigh(packet) elif packet.ptype == constants.SUBMIT_JOB_HIGH_BG: self.handleSubmitJobHighBg(packet) elif packet.ptype == constants.SUBMIT_JOB_LOW: self.handleSubmitJobLow(packet) elif packet.ptype == constants.SUBMIT_JOB_LOW_BG: self.handleSubmitJobLowBg(packet) elif packet.ptype == constants.SUBMIT_JOB_SCHED: self.handleSubmitJobSched(packet) elif packet.ptype == constants.SUBMIT_JOB_EPOCH: self.handleSubmitJobEpoch(packet) elif packet.ptype == constants.GRAB_JOB_UNIQ: self.handleGrabJobUniq(packet) elif packet.ptype == constants.GRAB_JOB: self.handleGrabJob(packet) elif packet.ptype == constants.PRE_SLEEP: self.handlePreSleep(packet) elif packet.ptype == constants.SET_CLIENT_ID: self.handleSetClientID(packet) elif packet.ptype == constants.CAN_DO: self.handleCanDo(packet) elif packet.ptype == constants.CAN_DO_TIMEOUT: self.handleCanDoTimeout(packet) elif packet.ptype == constants.CANT_DO: self.handleCantDo(packet) elif packet.ptype == constants.RESET_ABILITIES: self.handleResetAbilities(packet) elif packet.ptype == constants.ECHO_REQ: self.handleEchoReq(packet) elif packet.ptype == constants.ECHO_RES: self.handleEchoRes(packet) elif packet.ptype == constants.ERROR: self.handleError(packet) elif packet.ptype == constants.ALL_YOURS: self.handleAllYours(packet) elif packet.ptype == constants.OPTION_REQ: self.handleOptionReq(packet) elif packet.ptype == constants.OPTION_RES: self.handleOptionRes(packet) else: self.log.error("Received unknown packet: %s" % packet) def _defaultPacketHandler(self, packet): self.log.error("Received unhandled packet: %s" % packet) def handleJobCreated(self, packet): return self._defaultPacketHandler(packet) def handleWorkComplete(self, packet): return self._defaultPacketHandler(packet) def handleWorkFail(self, packet): return self._defaultPacketHandler(packet) def handleWorkException(self, packet): return self._defaultPacketHandler(packet) def handleWorkData(self, packet): return self._defaultPacketHandler(packet) def handleWorkWarning(self, packet): return self._defaultPacketHandler(packet) def handleWorkStatus(self, packet): return self._defaultPacketHandler(packet) def handleStatusRes(self, packet): return self._defaultPacketHandler(packet) def handleGetStatus(self, packet): return self._defaultPacketHandler(packet) def handleJobAssignUnique(self, packet): return self._defaultPacketHandler(packet) def handleJobAssign(self, packet): return self._defaultPacketHandler(packet) def handleNoJob(self, packet): return self._defaultPacketHandler(packet) def handleNoop(self, packet): return self._defaultPacketHandler(packet) def handleSubmitJob(self, packet): return self._defaultPacketHandler(packet) def handleSubmitJobBg(self, packet): return self._defaultPacketHandler(packet) def handleSubmitJobHigh(self, packet): return self._defaultPacketHandler(packet) def handleSubmitJobHighBg(self, packet): return self._defaultPacketHandler(packet) def handleSubmitJobLow(self, packet): return self._defaultPacketHandler(packet) def handleSubmitJobLowBg(self, packet): return self._defaultPacketHandler(packet) def handleSubmitJobSched(self, packet): return self._defaultPacketHandler(packet) def handleSubmitJobEpoch(self, packet): return self._defaultPacketHandler(packet) def handleGrabJobUniq(self, packet): return self._defaultPacketHandler(packet) def handleGrabJob(self, packet): return self._defaultPacketHandler(packet) def handlePreSleep(self, packet): return self._defaultPacketHandler(packet) def handleSetClientID(self, packet): return self._defaultPacketHandler(packet) def handleCanDo(self, packet): return self._defaultPacketHandler(packet) def handleCanDoTimeout(self, packet): return self._defaultPacketHandler(packet) def handleCantDo(self, packet): return self._defaultPacketHandler(packet) def handleResetAbilities(self, packet): return self._defaultPacketHandler(packet) def handleEchoReq(self, packet): return self._defaultPacketHandler(packet) def handleEchoRes(self, packet): return self._defaultPacketHandler(packet) def handleError(self, packet): return self._defaultPacketHandler(packet) def handleAllYours(self, packet): return self._defaultPacketHandler(packet) def handleOptionReq(self, packet): return self._defaultPacketHandler(packet) def handleOptionRes(self, packet): return self._defaultPacketHandler(packet) def handleAdminRequest(self, request): """Handle an administrative command response from Gearman. This method is called whenever a response to a previously issued administrative command is received from one of this client's connections. It normally releases the wait lock on the initiating AdminRequest object. :arg AdminRequest request: The :py:class:`AdminRequest` that initiated the received response. """ self.log.debug("Received admin data %s" % request) request.setComplete() def shutdown(self): """Close all connections and stop all running threads. The object may no longer be used after shutdown is called. """ self.log.debug("Beginning shutdown") self._shutdown() self.log.debug("Beginning cleanup") self._cleanup() self.log.debug("Finished shutdown") def _shutdown(self): # The first part of the shutdown process where all threads # are told to exit. self.running = False self.connections_condition.acquire() self.connections_condition.notifyAll() os.write(self.wake_write, b'1\n') self.connections_condition.release() def _cleanup(self): # The second part of the shutdown process where we wait for all # threads to exit and then clean up. self.poll_thread.join() self.connect_thread.join() for connection in self.active_connections: connection.disconnect() self.active_connections = [] self.inactive_connections = [] class BaseClient(BaseClientServer): def __init__(self): super(BaseClient, self).__init__() # A lock to use when sending packets that set the state across # all known connections. Note that it doesn't necessarily need # to be used for all broadcasts, only those that affect multi- # connection state, such as setting options or functions. self.broadcast_lock = threading.RLock() def addServer(self, host, port=4730, ssl_key=None, ssl_cert=None, ssl_ca=None): """Add a server to the client's connection pool. Any number of Gearman servers may be added to a client. The client will connect to all of them and send jobs to them in a round-robin fashion. When servers are disconnected, the client will automatically remove them from the pool, continuously try to reconnect to them, and return them to the pool when reconnected. New servers may be added at any time. This is a non-blocking call that will return regardless of whether the initial connection succeeded. If you need to ensure that a connection is ready before proceeding, see :py:meth:`waitForServer`. When using SSL connections, all SSL files must be specified. :arg str host: The hostname or IP address of the server. :arg int port: The port on which the gearman server is listening. :arg str ssl_key: Path to the SSL private key. :arg str ssl_cert: Path to the SSL certificate. :arg str ssl_ca: Path to the CA certificate. :raises ConfigurationError: If the host/port combination has already been added to the client. """ self.log.debug("Adding server %s port %s" % (host, port)) self.connections_condition.acquire() try: for conn in self.active_connections + self.inactive_connections: if conn.host == host and conn.port == port: raise ConfigurationError("Host/port already specified") conn = Connection(host, port, ssl_key, ssl_cert, ssl_ca) self.inactive_connections.append(conn) self.connections_condition.notifyAll() finally: self.connections_condition.release() def waitForServer(self): """Wait for at least one server to be connected. Block until at least one gearman server is connected. """ connected = False while self.running: self.connections_condition.acquire() while self.running and not self.active_connections: self.log.debug("Waiting for at least one active connection") self.connections_condition.wait() if self.active_connections: self.log.debug("Active connection found") connected = True self.connections_condition.release() if connected: return def getConnection(self): """Return a connected server. Finds the next scheduled connected server in the round-robin rotation and returns it. It is not usually necessary to use this method external to the library, as more consumer-oriented methods such as submitJob already use it internally, but is available nonetheless if necessary. :returns: The next scheduled :py:class:`Connection` object. :rtype: :py:class:`Connection` :raises NoConnectedServersError: If there are not currently connected servers. """ conn = None try: self.connections_condition.acquire() if not self.active_connections: raise NoConnectedServersError("No connected Gearman servers") self.connection_index += 1 if self.connection_index >= len(self.active_connections): self.connection_index = 0 conn = self.active_connections[self.connection_index] finally: self.connections_condition.release() return conn def broadcast(self, packet): """Send a packet to all currently connected servers. :arg Packet packet: The :py:class:`Packet` to send. """ connections = self.active_connections[:] for connection in connections: try: self.sendPacket(packet, connection) except Exception: # Error handling is all done by sendPacket pass def sendPacket(self, packet, connection): """Send a packet to a single connection, removing it from the list of active connections if that fails. :arg Packet packet: The :py:class:`Packet` to send. :arg Connection connection: The :py:class:`Connection` on which to send the packet. """ try: connection.sendPacket(packet) return except Exception: self.log.exception("Exception while sending packet %s to %s" % (packet, connection)) # If we can't send the packet, discard the connection self._lostConnection(connection) raise def handleEchoRes(self, packet): """Handle an ECHO_RES packet. Causes the blocking :py:meth:`Connection.echo` invocation to return. :arg Packet packet: The :py:class:`Packet` that was received. :returns: None """ packet.connection.handleEchoRes(packet.getArgument(0, True)) def handleError(self, packet): """Handle an ERROR packet. Logs the error. :arg Packet packet: The :py:class:`Packet` that was received. :returns: None """ self.log.error("Received ERROR packet: %s: %s" % (packet.getArgument(0), packet.getArgument(1))) try: task = packet.connection.pending_tasks.pop(0) task.setComplete() except Exception: self.log.exception("Exception while handling error packet:") self._lostConnection(packet.connection)
[docs]class Client(BaseClient): """A Gearman client. You may wish to subclass this class in order to override the default event handlers to react to Gearman events. Be sure to call the superclass event handlers so that they may perform job-related housekeeping. """ log = logging.getLogger("gear.Client") def __init__(self): super(Client, self).__init__() self.options = set() def __repr__(self): return '<gear.Client 0x%x>' % id(self) def _onConnect(self, conn): # Called immediately after a successful (re-)connection self.broadcast_lock.acquire() try: super(Client, self)._onConnect(conn) for name in self.options: self._setOptionConnection(name, conn) finally: self.broadcast_lock.release() def _setOptionConnection(self, name, conn): # Set an option on a connection packet = Packet(constants.REQ, constants.OPTION_REQ, name) task = OptionReqTask() try: conn.pending_tasks.append(task) self.sendPacket(packet, conn) except Exception: # Error handling is all done by sendPacket task = None return task
[docs] def setOption(self, name, timeout=30): """Set an option for all connections. :arg str name: The option name to set. :arg int timeout: How long to wait (in seconds) for a response from the server before giving up (default: 30 seconds). :returns: True if the option was set on all connections, otherwise False :rtype: bool """ tasks = {} name = convert_to_bytes(name) self.broadcast_lock.acquire() try: self.options.add(name) connections = self.active_connections[:] for connection in connections: task = self._setOptionConnection(name, connection) if task: tasks[task] = connection finally: self.broadcast_lock.release() success = True for task in tasks.keys(): complete = task.wait(timeout) conn = tasks[task] if not complete: self.log.error("Connection %s timed out waiting for a " "response to an option request: %s" % (conn, name)) self._lostConnection(conn) continue if name not in conn.options: success = False return success
[docs] def submitJob(self, job, background=False, precedence=PRECEDENCE_NORMAL, timeout=30): """Submit a job to a Gearman server. Submits the provided job to the next server in this client's round-robin connection pool. If the job is a foreground job, updates will be made to the supplied :py:class:`Job` object as they are received. :arg Job job: The :py:class:`Job` to submit. :arg bool background: Whether the job should be backgrounded. :arg int precedence: Whether the job should have normal, low, or high precedence. One of :py:data:`PRECEDENCE_NORMAL`, :py:data:`PRECEDENCE_LOW`, or :py:data:`PRECEDENCE_HIGH` :arg int timeout: How long to wait (in seconds) for a response from the server before giving up (default: 30 seconds). :raises ConfigurationError: If an invalid precendence value is supplied. """ if job.unique is None: unique = b'' else: unique = job.unique data = b'\x00'.join((job.name, unique, job.arguments)) if background: if precedence == PRECEDENCE_NORMAL: cmd = constants.SUBMIT_JOB_BG elif precedence == PRECEDENCE_LOW: cmd = constants.SUBMIT_JOB_LOW_BG elif precedence == PRECEDENCE_HIGH: cmd = constants.SUBMIT_JOB_HIGH_BG else: raise ConfigurationError("Invalid precedence value") else: if precedence == PRECEDENCE_NORMAL: cmd = constants.SUBMIT_JOB elif precedence == PRECEDENCE_LOW: cmd = constants.SUBMIT_JOB_LOW elif precedence == PRECEDENCE_HIGH: cmd = constants.SUBMIT_JOB_HIGH else: raise ConfigurationError("Invalid precedence value") packet = Packet(constants.REQ, cmd, data) while True: conn = self.getConnection() task = SubmitJobTask(job) conn.pending_tasks.append(task) try: self.sendPacket(packet, conn) except Exception: # Error handling is all done by sendPacket continue complete = task.wait(timeout) if not complete: self.log.error("Connection %s timed out waiting for a " "response to a submit job request: %s" % (conn, job)) self._lostConnection(conn) continue if not job.handle: self.log.error("Connection %s sent an error in " "response to a submit job request: %s" % (conn, job)) continue job.connection = conn return raise GearmanError("Unable to submit job to any connected servers")
[docs] def handleJobCreated(self, packet): """Handle a JOB_CREATED packet. Updates the appropriate :py:class:`Job` with the newly returned job handle. :arg Packet packet: The :py:class:`Packet` that was received. :returns: The :py:class:`Job` object associated with the job request. :rtype: :py:class:`Job` """ task = packet.connection.pending_tasks.pop(0) if not isinstance(task, SubmitJobTask): msg = ("Unexpected response received to submit job " "request: %s" % packet) self.log.error(msg) self._lostConnection(packet.connection) raise GearmanError(msg) job = task.job job.handle = packet.data packet.connection.related_jobs[job.handle] = job task.setComplete() self.log.debug("Job created; handle: %s" % job.handle) return job
[docs] def handleWorkComplete(self, packet): """Handle a WORK_COMPLETE packet. Updates the referenced :py:class:`Job` with the returned data and removes it from the list of jobs associated with the connection. :arg Packet packet: The :py:class:`Packet` that was received. :returns: The :py:class:`Job` object associated with the job request. :rtype: :py:class:`Job` """ job = packet.getJob() data = packet.getArgument(1, True) if data: job.data.append(data) job.complete = True job.failure = False del packet.connection.related_jobs[job.handle] self.log.debug("Job complete; handle: %s data: %s" % (job.handle, job.data)) return job
[docs] def handleWorkFail(self, packet): """Handle a WORK_FAIL packet. Updates the referenced :py:class:`Job` with the returned data and removes it from the list of jobs associated with the connection. :arg Packet packet: The :py:class:`Packet` that was received. :returns: The :py:class:`Job` object associated with the job request. :rtype: :py:class:`Job` """ job = packet.getJob() job.complete = True job.failure = True del packet.connection.related_jobs[job.handle] self.log.debug("Job failed; handle: %s" % job.handle) return job
[docs] def handleWorkException(self, packet): """Handle a WORK_Exception packet. Updates the referenced :py:class:`Job` with the returned data and removes it from the list of jobs associated with the connection. :arg Packet packet: The :py:class:`Packet` that was received. :returns: The :py:class:`Job` object associated with the job request. :rtype: :py:class:`Job` """ job = packet.getJob() job.exception = packet.getArgument(1, True) job.complete = True job.failure = True del packet.connection.related_jobs[job.handle] self.log.debug("Job exception; handle: %s data: %s" % (job.handle, job.exception)) return job
[docs] def handleWorkData(self, packet): """Handle a WORK_DATA packet. Updates the referenced :py:class:`Job` with the returned data. :arg Packet packet: The :py:class:`Packet` that was received. :returns: The :py:class:`Job` object associated with the job request. :rtype: :py:class:`Job` """ job = packet.getJob() data = packet.getArgument(1, True) if data: job.data.append(data) self.log.debug("Job data; handle: %s data: %s" % (job.handle, job.data)) return job
[docs] def handleWorkWarning(self, packet): """Handle a WORK_WARNING packet. Updates the referenced :py:class:`Job` with the returned data. :arg Packet packet: The :py:class:`Packet` that was received. :returns: The :py:class:`Job` object associated with the job request. :rtype: :py:class:`Job` """ job = packet.getJob() data = packet.getArgument(1, True) if data: job.data.append(data) job.warning = True self.log.debug("Job warning; handle: %s data: %s" % (job.handle, job.data)) return job
[docs] def handleWorkStatus(self, packet): """Handle a WORK_STATUS packet. Updates the referenced :py:class:`Job` with the returned data. :arg Packet packet: The :py:class:`Packet` that was received. :returns: The :py:class:`Job` object associated with the job request. :rtype: :py:class:`Job` """ job = packet.getJob() job.numerator = packet.getArgument(1) job.denominator = packet.getArgument(2) try: job.fraction_complete = (float(job.numerator) / float(job.denominator)) except Exception: job.fraction_complete = None self.log.debug("Job status; handle: %s complete: %s/%s" % (job.handle, job.numerator, job.denominator)) return job
[docs] def handleStatusRes(self, packet): """Handle a STATUS_RES packet. Updates the referenced :py:class:`Job` with the returned data. :arg Packet packet: The :py:class:`Packet` that was received. :returns: The :py:class:`Job` object associated with the job request. :rtype: :py:class:`Job` """ job = packet.getJob() job.known = (packet.getArgument(1) == 1) job.running = (packet.getArgument(2) == 1) job.numerator = packet.getArgument(3) job.denominator = packet.getArgument(4) try: job.fraction_complete = (float(job.numerator) / float(job.denominator)) except Exception: job.fraction_complete = None return job
[docs] def handleOptionRes(self, packet): """Handle an OPTION_RES packet. Updates the set of options for the connection. :arg Packet packet: The :py:class:`Packet` that was received. :returns: None. """ task = packet.connection.pending_tasks.pop(0) if not isinstance(task, OptionReqTask): msg = ("Unexpected response received to option " "request: %s" % packet) self.log.error(msg) self._lostConnection(packet.connection) raise GearmanError(msg) packet.connection.handleOptionRes(packet.getArgument(0)) task.setComplete()
[docs] def handleDisconnect(self, job): """Handle a Gearman server disconnection. If the Gearman server is disconnected, this will be called for any jobs currently associated with the server. :arg Job packet: The :py:class:`Job` that was running when the server disconnected. """ return job
[docs]class FunctionRecord(object): """Represents a function that should be registered with Gearman. This class only directly needs to be instatiated for use with :py:meth:`Worker.setFunctions`. If a timeout value is supplied, the function will be registered with CAN_DO_TIMEOUT. :arg str name: The name of the function to register. :arg numeric timeout: The timeout value (optional). """ def __init__(self, name, timeout=None): self.name = name self.timeout = timeout def __repr__(self): return '<gear.FunctionRecord 0x%x name: %s timeout: %s>' % ( id(self), self.name, self.timeout)
[docs]class Worker(BaseClient): """A Gearman worker. :arg str worker_id: The worker ID to provide to Gearman (will appear in administrative command output). """ log = logging.getLogger("gear.Worker") def __init__(self, worker_id): self.worker_id = convert_to_bytes(worker_id) self.functions = {} self.job_lock = threading.Lock() self.waiting_for_jobs = 0 self.job_queue = queue.Queue() super(Worker, self).__init__() def __repr__(self): return '<gear.Worker 0x%x>' % id(self)
[docs] def registerFunction(self, name, timeout=None): """Register a function with Gearman. If a timeout value is supplied, the function will be registered with CAN_DO_TIMEOUT. :arg str name: The name of the function to register. :arg numeric timeout: The timeout value (optional). """ name = convert_to_bytes(name) self.functions[name] = FunctionRecord(name, timeout) if timeout: self._sendCanDoTimeout(name, timeout) else: self._sendCanDo(name)
[docs] def unRegisterFunction(self, name): """Remove a function from Gearman's registry. :arg str name: The name of the function to remove. """ name = convert_to_bytes(name) del self.functions[name] self._sendCantDo(name)
[docs] def setFunctions(self, functions): """Replace the set of functions registered with Gearman. Accepts a list of :py:class:`FunctionRecord` objects which represents the complete set of functions that should be registered with Gearman. Any existing functions will be unregistered and these registered in their place. If the empty list is supplied, then the Gearman registered function set will be cleared. :arg list functions: A list of :py:class:`FunctionRecord` objects. """ self._sendResetAbilities() self.functions = {} for f in functions: if not isinstance(f, FunctionRecord): raise InvalidDataError( "An iterable of FunctionRecords is required.") self.functions[f.name] = f for f in self.functions.values(): if f.timeout: self._sendCanDoTimeout(f.name, f.timeout) else: self._sendCanDo(f.name)
def _sendCanDo(self, name): self.broadcast_lock.acquire() try: p = Packet(constants.REQ, constants.CAN_DO, name) self.broadcast(p) finally: self.broadcast_lock.release() def _sendCanDoTimeout(self, name, timeout): self.broadcast_lock.acquire() try: data = name + b'\x00' + timeout p = Packet(constants.REQ, constants.CAN_DO_TIMEOUT, data) self.broadcast(p) finally: self.broadcast_lock.release() def _sendCantDo(self, name): self.broadcast_lock.acquire() try: p = Packet(constants.REQ, constants.CANT_DO, name) self.broadcast(p) finally: self.broadcast_lock.release() def _sendResetAbilities(self): self.broadcast_lock.acquire() try: p = Packet(constants.REQ, constants.RESET_ABILITIES, b'') self.broadcast(p) finally: self.broadcast_lock.release() def _sendPreSleep(self, connection): p = Packet(constants.REQ, constants.PRE_SLEEP, b'') self.sendPacket(p, connection) def _sendGrabJobUniq(self, connection=None): p = Packet(constants.REQ, constants.GRAB_JOB_UNIQ, b'') if connection: self.sendPacket(p, connection) else: self.broadcast(p) def _onConnect(self, conn): self.broadcast_lock.acquire() try: # Called immediately after a successful (re-)connection p = Packet(constants.REQ, constants.SET_CLIENT_ID, self.worker_id) conn.sendPacket(p) super(Worker, self)._onConnect(conn) for f in self.functions.values(): if f.timeout: data = f.name + b'\x00' + f.timeout p = Packet(constants.REQ, constants.CAN_DO_TIMEOUT, data) else: p = Packet(constants.REQ, constants.CAN_DO, f.name) conn.sendPacket(p) conn.changeState("IDLE") finally: self.broadcast_lock.release() # Any exceptions will be handled by the calling function, and the # connection will not be put into the pool. def _onActiveConnection(self, conn): self.job_lock.acquire() try: if self.waiting_for_jobs > 0: self._updateStateMachines() finally: self.job_lock.release() def _updateStateMachines(self): connections = self.active_connections[:] for connection in connections: if (connection.state == "IDLE" and self.waiting_for_jobs > 0): self._sendGrabJobUniq(connection) connection.changeState("GRAB_WAIT") if (connection.state != "IDLE" and self.waiting_for_jobs < 1): connection.changeState("IDLE")
[docs] def getJob(self): """Get a job from Gearman. Blocks until a job is received. This method is re-entrant, so it is safe to call this method on a single worker from multiple threads. In that case, one of them at random will receive the job assignment. :returns: The :py:class:`WorkerJob` assigned. :rtype: :py:class:`WorkerJob`. :raises InterruptedError: If interrupted (by :py:meth:`stopWaitingForJobs`) before a job is received. """ self.job_lock.acquire() try: self.waiting_for_jobs += 1 self.log.debug("Get job; number of threads waiting for jobs: %s" % self.waiting_for_jobs) try: job = self.job_queue.get(False) except queue.Empty: job = None if not job: self._updateStateMachines() finally: self.job_lock.release() if not job: job = self.job_queue.get() self.log.debug("Received job: %s" % job) if job is None: raise InterruptedError() return job
[docs] def stopWaitingForJobs(self): """Interrupts all running :py:meth:`getJob` calls, which will raise an exception. """ self.job_lock.acquire() while True: connections = self.active_connections[:] now = time.time() ok = True for connection in connections: if connection.state == "GRAB_WAIT": # Replies to GRAB_JOB should be fast, give up if we've # been waiting for more than 5 seconds. if now - connection.state_time > 5: self._lostConnection(connection) else: ok = False if ok: break else: self.job_lock.release() time.sleep(0.1) self.job_lock.acquire() while self.waiting_for_jobs > 0: self.waiting_for_jobs -= 1 self.job_queue.put(None) self._updateStateMachines() self.job_lock.release()
def _shutdown(self): super(Worker, self)._shutdown() self.stopWaitingForJobs()
[docs] def handleNoop(self, packet): """Handle a NOOP packet. Sends a GRAB_JOB_UNIQ packet on the same connection. GRAB_JOB_UNIQ will return jobs regardless of whether they have been specified with a unique identifier when submitted. If they were not, then :py:attr:`WorkerJob.unique` attribute will be None. :arg Packet packet: The :py:class:`Packet` that was received. """ self.job_lock.acquire() try: if packet.connection.state == "SLEEP": self.log.debug("Sending GRAB_JOB_UNIQ") self._sendGrabJobUniq(packet.connection) packet.connection.changeState("GRAB_WAIT") else: self.log.debug("Received unexpecetd NOOP packet on %s" % packet.connection) finally: self.job_lock.release()
[docs] def handleNoJob(self, packet): """Handle a NO_JOB packet. Sends a PRE_SLEEP packet on the same connection. :arg Packet packet: The :py:class:`Packet` that was received. """ self.job_lock.acquire() try: if packet.connection.state == "GRAB_WAIT": self.log.debug("Sending PRE_SLEEP") self._sendPreSleep(packet.connection) packet.connection.changeState("SLEEP") else: self.log.debug("Received unexpected NO_JOB packet on %s" % packet.connection) finally: self.job_lock.release()
[docs] def handleJobAssign(self, packet): """Handle a JOB_ASSIGN packet. Adds a WorkerJob to the internal queue to be picked up by any threads waiting in :py:meth:`getJob`. :arg Packet packet: The :py:class:`Packet` that was received. """ handle = packet.getArgument(0) name = packet.getArgument(1) arguments = packet.getArgument(2, True) return self._handleJobAssignment(packet, handle, name, arguments, None)
[docs] def handleJobAssignUnique(self, packet): """Handle a JOB_ASSIGN_UNIQ packet. Adds a WorkerJob to the internal queue to be picked up by any threads waiting in :py:meth:`getJob`. :arg Packet packet: The :py:class:`Packet` that was received. """ handle = packet.getArgument(0) name = packet.getArgument(1) unique = packet.getArgument(2) if unique == b'': unique = None arguments = packet.getArgument(3, True) return self._handleJobAssignment(packet, handle, name, arguments, unique)
def _handleJobAssignment(self, packet, handle, name, arguments, unique): job = WorkerJob(handle, name, arguments, unique) job.connection = packet.connection self.job_lock.acquire() try: packet.connection.changeState("IDLE") self.waiting_for_jobs -= 1 self.log.debug("Job assigned; number of threads waiting for " "jobs: %s" % self.waiting_for_jobs) self.job_queue.put(job) self._updateStateMachines() finally: self.job_lock.release()
class BaseJob(object): log = logging.getLogger("gear.Job") def __init__(self, name, arguments, unique=None, handle=None): self.name = convert_to_bytes(name) if (not isinstance(arguments, bytes) and not isinstance(arguments, bytearray)): raise TypeError("arguments must be of type bytes or bytearray") self.arguments = arguments self.unique = convert_to_bytes(unique) self.handle = handle self.connection = None def __repr__(self): return '<gear.Job 0x%x handle: %s name: %s unique: %s>' % ( id(self), self.handle, self.name, self.unique)
[docs]class Job(BaseJob): """A job to run or being run by Gearman. :arg str name: The name of the job. :arg bytes arguments: The opaque data blob to be passed to the worker as arguments. :arg str unique: A byte string to uniquely identify the job to Gearman (optional). The following instance attributes are available: **name** (str) The name of the job. **arguments** (bytes) The opaque data blob passed to the worker as arguments. **unique** (str or None) The unique ID of the job (if supplied). **handle** (bytes or None) The Gearman job handle. None if no job handle has been received yet. **data** (list of byte-arrays) The result data returned from Gearman. Each packet appends an element to the list. Depending on the nature of the data, the elements may need to be concatenated before use. **exception** (bytes or None) Exception information returned from Gearman. None if no exception has been received. **warning** (bool) Whether the worker has reported a warning. **complete** (bool) Whether the job is complete. **failure** (bool) Whether the job has failed. Only set when complete is True. **numerator** (bytes or None) The numerator of the completion ratio reported by the worker. Only set when a status update is sent by the worker. **denominator** (bytes or None) The denominator of the completion ratio reported by the worker. Only set when a status update is sent by the worker. **fraction_complete** (float or None) The fractional complete ratio reported by the worker. Only set when a status update is sent by the worker. **known** (bool or None) Whether the job is known to Gearman. Only set by handleStatusRes() in response to a getStatus() query. **running** (bool or None) Whether the job is running. Only set by handleStatusRes() in response to a getStatus() query. **connection** (:py:class:`Connection` or None) The connection associated with the job. Only set after the job has been submitted to a Gearman server. """ log = logging.getLogger("gear.Job") def __init__(self, name, arguments, unique=None): super(Job, self).__init__(name, arguments, unique) self.data = [] self.exception = None self.warning = False self.complete = False self.failure = False self.numerator = None self.denominator = None self.fraction_complete = None self.known = None self.running = None
[docs]class WorkerJob(BaseJob): """A job that Gearman has assigned to a Worker. Not intended to be instantiated directly, but rather returned by :py:meth:`Worker.getJob`. :arg str handle: The job handle assigned by gearman. :arg str name: The name of the job. :arg bytes arguments: The opaque data blob passed to the worker as arguments. :arg str unique: A byte string to uniquely identify the job to Gearman (optional). The following instance attributes are available: **name** (str) The name of the job. **arguments** (bytes) The opaque data blob passed to the worker as arguments. **unique** (str or None) The unique ID of the job (if supplied). **handle** (bytes) The Gearman job handle. **connection** (:py:class:`Connection` or None) The connection associated with the job. Only set after the job has been submitted to a Gearman server. """ log = logging.getLogger("gear.WorkerJob") def __init__(self, handle, name, arguments, unique=None): super(WorkerJob, self).__init__(name, arguments, unique, handle)
[docs] def sendWorkData(self, data=b''): """Send a WORK_DATA packet to the client. :arg bytes data: The data to be sent to the client (optional). """ data = self.handle + b'\x00' + data p = Packet(constants.REQ, constants.WORK_DATA, data) self.connection.sendPacket(p)
[docs] def sendWorkWarning(self, data=b''): """Send a WORK_WARNING packet to the client. :arg bytes data: The data to be sent to the client (optional). """ data = self.handle + b'\x00' + data p = Packet(constants.REQ, constants.WORK_WARNING, data) self.connection.sendPacket(p)
[docs] def sendWorkStatus(self, numerator, denominator): """Send a WORK_STATUS packet to the client. Sends a numerator and denominator that together represent the fraction complete of the job. :arg numeric numerator: The numerator of the fraction complete. :arg numeric denominator: The denominator of the fraction complete. """ data = (self.handle + b'\x00' + str(numerator).encode('utf8') + b'\x00' + str(denominator).encode('utf8')) p = Packet(constants.REQ, constants.WORK_STATUS, data) self.connection.sendPacket(p)
[docs] def sendWorkComplete(self, data=b''): """Send a WORK_COMPLETE packet to the client. :arg bytes data: The data to be sent to the client (optional). """ data = self.handle + b'\x00' + data p = Packet(constants.REQ, constants.WORK_COMPLETE, data) self.connection.sendPacket(p)
[docs] def sendWorkFail(self): "Send a WORK_FAIL packet to the client." p = Packet(constants.REQ, constants.WORK_FAIL, self.handle) self.connection.sendPacket(p)
[docs] def sendWorkException(self, data=b''): """Send a WORK_EXCEPTION packet to the client. :arg bytes data: The exception data to be sent to the client (optional). """ data = self.handle + b'\x00' + data p = Packet(constants.REQ, constants.WORK_EXCEPTION, data) self.connection.sendPacket(p) # Below are classes for use in the server implementation:
class ServerJob(Job): """A job record for use in a server. :arg str name: The name of the job. :arg bytes arguments: The opaque data blob to be passed to the worker as arguments. :arg str unique: A byte string to uniquely identify the job to Gearman (optional). The following instance attributes are available: **name** (str) The name of the job. **arguments** (bytes) The opaque data blob passed to the worker as arguments. **unique** (str or None) The unique ID of the job (if supplied). **handle** (bytes or None) The Gearman job handle. None if no job handle has been received yet. **data** (list of byte-arrays) The result data returned from Gearman. Each packet appends an element to the list. Depending on the nature of the data, the elements may need to be concatenated before use. **exception** (bytes or None) Exception information returned from Gearman. None if no exception has been received. **warning** (bool) Whether the worker has reported a warning. **complete** (bool) Whether the job is complete. **failure** (bool) Whether the job has failed. Only set when complete is True. **numerator** (bytes or None) The numerator of the completion ratio reported by the worker. Only set when a status update is sent by the worker. **denominator** (bytes or None) The denominator of the completion ratio reported by the worker. Only set when a status update is sent by the worker. **fraction_complete** (float or None) The fractional complete ratio reported by the worker. Only set when a status update is sent by the worker. **known** (bool or None) Whether the job is known to Gearman. Only set by handleStatusRes() in response to a getStatus() query. **running** (bool or None) Whether the job is running. Only set by handleStatusRes() in response to a getStatus() query. **client_connection** :py:class:`Connection` The client connection associated with the job. **worker_connection** (:py:class:`Connection` or None) The worker connection associated with the job. Only set after the job has been assigned to a worker. """ log = logging.getLogger("gear.ServerJob") def __init__(self, handle, name, arguments, client_connection, unique=None): super(ServerJob, self).__init__(name, arguments, unique) self.handle = handle self.client_connection = client_connection self.worker_connection = None del self.connection class ServerAdminRequest(AdminRequest): """An administrative request sent to a server.""" def __init__(self, connection): super(ServerAdminRequest, self).__init__() self.connection = connection def isComplete(self, data): if data[-1:] == b'\n': self.command = data.strip() return True return False class ServerConnection(Connection): """A Connection to a Gearman Client.""" def __init__(self, addr, conn): self.host = addr[0] self.port = addr[1] self.conn = conn self.client_id = None self.functions = set() self.related_jobs = {} self.changeState("INIT") def _getAdminRequest(self): return ServerAdminRequest(self) def __repr__(self): if self.client_id: name = self.client_id else: name = '0x%x' % id(self) return '<gear.Connection name: %s host: %s port: %s>' % ( name, self.host, self.port)
[docs]class Server(BaseClientServer): """A simple gearman server implementation for testing (not for production use). :arg int port: The TCP port on which to listen. """ def __init__(self, port=4730, ssl_key=None, ssl_cert=None, ssl_ca=None): self.port = port self.ssl_key = ssl_key self.ssl_cert = ssl_cert self.ssl_ca = ssl_ca self.high_queue = [] self.normal_queue = [] self.low_queue = [] self.jobs = {} self.functions = set() self.max_handle = 0 self.connect_wake_read, self.connect_wake_write = os.pipe() for res in socket.getaddrinfo(None, self.port, socket.AF_UNSPEC, socket.SOCK_STREAM, 0, socket.AI_PASSIVE): af, socktype, proto, canonname, sa = res try: self.socket = socket.socket(af, socktype, proto) self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) except socket.error: self.socket = None continue try: self.socket.bind(sa) self.socket.listen(1) except socket.error: self.socket.close() self.socket = None continue break if self.socket is None: raise Exception("Could not open socket") if port == 0: self.port = self.socket.getsockname()[1] super(Server, self).__init__() def _doConnectLoop(self): while self.running: try: self.connectLoop() except Exception: self.log.exception("Exception in connect loop:") def connectLoop(self): poll = select.poll() bitmask = (select.POLLIN | select.POLLERR | select.POLLHUP | select.POLLNVAL) # Register the wake pipe so that we can break if we need to # shutdown. poll.register(self.connect_wake_read, bitmask) poll.register(self.socket.fileno(), bitmask) while self.running: ret = poll.poll() for fd, event in ret: if fd == self.connect_wake_read: self.log.debug("Accept woken by pipe") while True: if os.read(self.connect_wake_read, 1) == b'\n': break return if event & select.POLLIN: self.log.debug("Accepting new connection") c, addr = self.socket.accept() self.log.debug("Accepted new connection") if all([self.ssl_key, self.ssl_cert, self.ssl_ca]): c = ssl.wrap_socket(c, server_side=True, keyfile=self.ssl_key, certfile=self.ssl_cert, ca_certs=self.ssl_ca, cert_reqs=ssl.CERT_REQUIRED, ssl_version=ssl.PROTOCOL_TLSv1) conn = ServerConnection(addr, c) self.connections_condition.acquire() self.active_connections.append(conn) self.connections_condition.notifyAll() os.write(self.wake_write, b'1\n') self.connections_condition.release() def _shutdown(self): super(Server, self)._shutdown() os.write(self.connect_wake_write, b'1\n') def _cleanup(self): super(Server, self)._cleanup() self.socket.close() def _lostConnection(self, conn): # Called as soon as a connection is detected as faulty. self.log.debug("Marking %s as disconnected" % conn) self.connections_condition.acquire() jobs = conn.related_jobs.values() self.active_connections.remove(conn) self.connections_condition.notifyAll() self.connections_condition.release() for job in jobs: if job.worker_connection == conn: # the worker disconnected, alert the client try: p = Packet(constants.REQ, constants.WORK_FAIL, job.handle) job.client_connection.sendPacket(p) except Exception: self.log.exception("Sending WORK_FAIL to client after " "worker disconnect failed:") del job.client_connection.related_jobs[job.handle] if job.worker_connection: del job.worker_connection.related_jobs[job.handle] del self.jobs[job.handle]
[docs] def getQueue(self): """Returns a copy of all internal queues in a flattened form. :returns: The Gearman queue. :rtype: list of :py:class:`WorkerJob`. """ ret = [] for queue in [self.high_queue, self.normal_queue, self.low_queue]: ret += queue return ret
def handleAdminRequest(self, request): if request.command.startswith(b'cancel job'): self.handleCancelJob(request) elif request.command.startswith(b'status'): self.handleStatus(request) elif request.command.startswith(b'workers'): self.handleWorkers(request) def handleCancelJob(self, request): words = request.command.split() handle = words[2] if handle in self.jobs: for queue in [self.high_queue, self.normal_queue, self.low_queue]: for job in queue: if handle == job.handle: queue.remove(job) del self.jobs[handle] request.connection.conn.send(b'OK\n') return request.connection.conn.send(b'ERR UNKNOWN_JOB\n') def handleStatus(self, request): functions = {} for function in self.functions: # Total, running, workers functions[function] = [0, 0, 0] for job in self.jobs.values(): functions[job.name][0] += 1 if job.running: functions[job.name][1] += 1 for connection in self.active_connections: for function in connection.functions: functions[function][2] += 1 for name, values in functions.items(): request.connection.conn.send(("%s\t%s\t%s\t%s\n" % (name, values[0], values[1], values[2])).encode('utf8')) request.connection.conn.send(b'.\n') def handleWorkers(self, request): for connection in self.active_connections: fd = connection.conn.fileno() ip = connection.host client_id = connection.client_id or '-' functions = ' '.join(connection.functions) request.connection.conn.send(("%s %s %s : %s\n" % (fd, ip, client_id, functions)) .encode('utf8')) request.connection.conn.send(b'.\n') def wakeConnections(self): p = Packet(constants.RES, constants.NOOP, b'') for connection in self.active_connections: if connection.state == 'SLEEP': connection.changeState("AWAKE") connection.sendPacket(p) def _handleSubmitJob(self, packet, precedence): name = packet.getArgument(0) unique = packet.getArgument(1) if not unique: unique = None arguments = packet.getArgument(2, True) self.max_handle += 1 handle = ('H:%s:%s' % (packet.connection.host, self.max_handle)).encode('utf8') job = ServerJob(handle, name, arguments, packet.connection, unique) p = Packet(constants.RES, constants.JOB_CREATED, handle) packet.connection.sendPacket(p) self.jobs[handle] = job packet.connection.related_jobs[handle] = job if precedence == PRECEDENCE_HIGH: self.high_queue.append(job) elif precedence == PRECEDENCE_NORMAL: self.normal_queue.append(job) elif precedence == PRECEDENCE_LOW: self.low_queue.append(job) self.wakeConnections() def handleSubmitJob(self, packet): return self._handleSubmitJob(packet, PRECEDENCE_NORMAL) def handleSubmitJobHigh(self, packet): return self._handleSubmitJob(packet, PRECEDENCE_HIGH) def handleSubmitJobLow(self, packet): return self._handleSubmitJob(packet, PRECEDENCE_LOW) def getJobForConnection(self, connection, peek=False): for queue in [self.high_queue, self.normal_queue, self.low_queue]: for job in queue: if job.name in connection.functions: if not peek: queue.remove(job) connection.related_jobs[job.handle] = job job.worker_connection = connection job.running = True return job return None def handleGrabJobUniq(self, packet): job = self.getJobForConnection(packet.connection) if job: self.sendJobAssignUniq(packet.connection, job) else: self.sendNoJob(packet.connection) def sendJobAssignUniq(self, connection, job): unique = job.unique if not unique: unique = b'' data = b'\x00'.join((job.handle, job.name, unique, job.arguments)) p = Packet(constants.RES, constants.JOB_ASSIGN_UNIQ, data) connection.sendPacket(p) def sendNoJob(self, connection): p = Packet(constants.RES, constants.NO_JOB, b'') connection.sendPacket(p) def handlePreSleep(self, packet): packet.connection.changeState("SLEEP") if self.getJobForConnection(packet.connection, peek=True): self.wakeConnections() def handleWorkComplete(self, packet): self.handlePassthrough(packet, True) def handleWorkFail(self, packet): self.handlePassthrough(packet, True) def handleWorkException(self, packet): self.handlePassthrough(packet, True) def handleWorkData(self, packet): self.handlePassthrough(packet) def handleWorkWarning(self, packet): self.handlePassthrough(packet) def handleWorkStatus(self, packet): handle = packet.getArgument(0) job = self.jobs.get(handle) if not job: raise UnknownJobError() job.numerator = packet.getArgument(1) job.denominator = packet.getArgument(2) self.handlePassthrough(packet) def handlePassthrough(self, packet, finished=False): handle = packet.getArgument(0) job = self.jobs.get(handle) if not job: raise UnknownJobError() packet.code = constants.RES job.client_connection.sendPacket(packet) if finished: del self.jobs[handle] del job.client_connection.related_jobs[handle] del job.worker_connection.related_jobs[handle] def handleSetClientID(self, packet): name = packet.getArgument(0) packet.connection.client_id = name def handleCanDo(self, packet): name = packet.getArgument(0) self.log.debug("Adding function %s to %s" % (name, packet.connection)) packet.connection.functions.add(name) self.functions.add(name) def handleCantDo(self, packet): name = packet.getArgument(0) self.log.debug("Removing function %s from %s" % (name, packet.connection)) packet.connection.functions.remove(name) def handleResetAbilities(self, packet): self.log.debug("Resetting functions for %s" % packet.connection) packet.connection.functions = set() def handleGetStatus(self, packet): handle = packet.getArgument(0) self.log.debug("Getting status for %s" % handle) known = 0 running = 0 numerator = b'' denominator = b'' job = self.jobs.get(handle) if job: known = 1 if job.running: running = 1 numerator = job.numerator or b'' denominator = job.denominator or b'' data = (handle + b'\x00' + str(known).encode('utf8') + b'\x00' + str(running).encode('utf8') + b'\x00' + numerator + b'\x00' + denominator) p = Packet(constants.RES, constants.STATUS_RES, data) packet.connection.sendPacket(p)

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