root / branches / 1.1 / src / haizea / core / scheduler / lease_scheduler.py @ 849
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# -------------------------------------------------------------------------- #
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# Copyright 2006-2009, University of Chicago #
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# Copyright 2008-2009, Distributed Systems Architecture Group, Universidad #
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# Complutense de Madrid (dsa-research.org) #
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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, #
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. #
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# See the License for the specific language governing permissions and #
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# limitations under the License. #
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# -------------------------------------------------------------------------- #
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"""This module provides the main classes for Haizea's lease scheduler, particularly
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the LeaseScheduler class. This module does *not* contain VM scheduling code (i.e.,
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the code that decides what physical hosts a VM should be mapped to), which is
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located in the vm_scheduler module. Lease preparation code (e.g., image transfer
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scheduling) is located in the preparation_schedulers package. In fact, the
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main purpose of the lease schedule is to orchestrate these preparation and VM
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schedulers.
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This module also includes a Queue class and a LeaseTable class, which are used
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by the lease scheduler.
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"""
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import haizea.common.constants as constants |
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from haizea.common.utils import round_datetime, get_config, get_clock, get_policy, get_persistence |
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from haizea.core.leases import Lease |
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from haizea.core.scheduler import RescheduleLeaseException, NormalEndLeaseException, InconsistentLeaseStateError, EnactmentError, UnrecoverableError, NotSchedulableException, EarliestStartingTime |
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from haizea.core.scheduler.vm_scheduler import VMResourceReservation |
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from haizea.core.scheduler.slottable import ResourceReservation |
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from operator import attrgetter |
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import logging |
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from mx.DateTime import DateTimeDelta |
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class LeaseScheduler(object): |
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"""The Haizea Lease Scheduler
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This is the main scheduling class in Haizea. It handles lease scheduling which,
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in turn, involves VM scheduling, preparation scheduling (such as transferring
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a VM image), and numerous bookkeeping operations. All these operations are
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handled by other classes, so this class acts mostly as an orchestrator that
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coordinates all the different operations involved in scheduling a lease.
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"""
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def __init__(self, vm_scheduler, preparation_scheduler, slottable, accounting): |
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"""Constructor
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The constructor does little more than create the lease scheduler's
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attributes. However, it does expect (in the arguments) a fully-constructed
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VMScheduler, PreparationScheduler, SlotTable, and PolicyManager (these are
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constructed in the Manager's constructor).
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Arguments:
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vm_scheduler -- VM scheduler
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preparation_scheduler -- Preparation scheduler
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slottable -- Slottable
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accounting -- AccountingDataCollection object
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"""
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# Logger
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self.logger = logging.getLogger("LSCHED") |
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# Assign schedulers and slottable
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self.vm_scheduler = vm_scheduler
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"""
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VM Scheduler
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@type: VMScheduler
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"""
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self.preparation_scheduler = preparation_scheduler
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self.slottable = slottable
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self.accounting = accounting
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# Create other data structures
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self.queue = Queue()
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self.leases = LeaseTable()
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self.completed_leases = LeaseTable()
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# Handlers are callback functions that get called whenever a type of
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# resource reservation starts or ends. Each scheduler publishes the
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# handlers it supports through its "handlers" attributes. For example,
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# the VMScheduler provides _handle_start_vm and _handle_end_vm that
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# must be called when a VMResourceReservation start or end is encountered
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# in the slot table.
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#
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# Handlers are called from the process_reservations method of this class
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self.handlers = {}
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for (type, handler) in self.vm_scheduler.handlers.items(): |
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self.handlers[type] = handler |
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for (type, handler) in self.preparation_scheduler.handlers.items(): |
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self.handlers[type] = handler |
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def request_lease(self, lease): |
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"""Requests a leases. This is the entry point of leases into the scheduler.
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Request a lease. The decision on whether to accept or reject a
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lease is deferred to the policy manager (through its admission
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control policy).
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If the policy determines the lease can be
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accepted, it is marked as "Pending". This still doesn't
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guarantee that the lease will be scheduled (e.g., an AR lease
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could still be rejected if the scheduler determines there are no
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resources for it; but that is a *scheduling* decision, not a admission
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control policy decision). The ultimate fate of the lease is determined
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the next time the scheduling function is called.
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If the policy determines the lease cannot be accepted, it is marked
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as rejected.
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Arguments:
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lease -- Lease object. Its state must be STATE_NEW.
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"""
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self.logger.info("Lease #%i has been requested." % lease.id) |
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if lease.submit_time == None: |
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lease.submit_time = round_datetime(get_clock().get_time()) |
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lease.print_contents() |
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lease.set_state(Lease.STATE_PENDING) |
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if get_policy().accept_lease(lease):
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self.logger.info("Lease #%i has been marked as pending." % lease.id) |
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self.leases.add(lease)
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else:
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self.logger.info("Lease #%i has not been accepted" % lease.id) |
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lease.set_state(Lease.STATE_REJECTED) |
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self.completed_leases.add(lease)
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self.accounting.at_lease_request(lease)
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get_persistence().persist_lease(lease) |
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def schedule(self, nexttime): |
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""" The main scheduling function
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The scheduling function looks at all pending requests and schedules them.
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Note that most of the actual scheduling code is contained in the
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__schedule_lease method and in the VMScheduler and PreparationScheduler classes.
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Arguments:
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nexttime -- The next time at which the scheduler can allocate resources.
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"""
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# Get pending leases
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pending_leases = self.leases.get_leases_by_state(Lease.STATE_PENDING)
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# Process leases that have to be queued. Right now, only best-effort leases get queued.
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queue_leases = [req for req in pending_leases if req.get_type() == Lease.BEST_EFFORT] |
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# Queue leases
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for lease in queue_leases: |
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self.__enqueue(lease)
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lease.set_state(Lease.STATE_QUEUED) |
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self.logger.info("Queued lease request #%i, %i nodes for %s." % (lease.id, lease.numnodes, lease.duration.requested)) |
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get_persistence().persist_lease(lease) |
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# Process leases that have to be scheduled right away. Right now, this is any
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# lease that is not a best-effort lease (ARs, immediate, and deadlined leases)
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now_leases = [req for req in pending_leases if req.get_type() != Lease.BEST_EFFORT] |
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# Schedule leases
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for lease in now_leases: |
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lease_type = Lease.type_str[lease.get_type()] |
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self.logger.info("Scheduling lease #%i (%i nodes) -- %s" % (lease.id, lease.numnodes, lease_type)) |
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if lease.get_type() == Lease.ADVANCE_RESERVATION:
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self.logger.info("From %s to %s" % (lease.start.requested, lease.start.requested + lease.duration.requested)) |
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elif lease.get_type() == Lease.DEADLINE:
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self.logger.info("Starting at %s. Deadline: %s" % (lease.start.requested, lease.deadline)) |
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lease.print_contents() |
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try:
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self.__schedule_lease(lease, nexttime=nexttime)
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self.logger.info("Lease #%i has been scheduled." % lease.id) |
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## BEGIN NOT-FIT-FOR-PRODUCTION CODE
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## This should happen when the lease is requested.
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get_policy().pricing.feedback(lease) |
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## END NOT-FIT-FOR-PRODUCTION CODE
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lease.print_contents() |
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except NotSchedulableException, exc:
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self.logger.info("Lease request #%i cannot be scheduled: %s" % (lease.id, exc.reason)) |
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## BEGIN NOT-FIT-FOR-PRODUCTION CODE
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## This should happen when the lease is requested.
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if lease.price == -1: |
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lease.set_state(Lease.STATE_REJECTED_BY_USER) |
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else:
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lease.set_state(Lease.STATE_REJECTED) |
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self.completed_leases.add(lease)
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self.accounting.at_lease_done(lease)
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## BEGIN NOT-FIT-FOR-PRODUCTION CODE
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## This should happen when the lease is requested.
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get_policy().pricing.feedback(lease) |
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## END NOT-FIT-FOR-PRODUCTION CODE
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self.leases.remove(lease)
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get_persistence().persist_lease(lease) |
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# Process queue (i.e., traverse queue in search of leases that can be scheduled)
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self.__process_queue(nexttime)
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get_persistence().persist_queue(self.queue)
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def process_starting_reservations(self, nowtime): |
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"""Processes starting reservations
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This method checks the slottable to see if there are any reservations that are
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starting at "nowtime". If so, the appropriate handler is called.
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Arguments:
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nowtime -- Time at which to check for starting reservations.
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"""
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# Find starting/ending reservations
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starting = self.slottable.get_reservations_starting_at(nowtime)
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starting = [res for res in starting if res.state == ResourceReservation.STATE_SCHEDULED] |
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# Process starting reservations
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for rr in starting: |
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lease = rr.lease |
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# Call the appropriate handler, and catch exceptions and errors.
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try:
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self.handlers[type(rr)].on_start(lease, rr) |
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# An InconsistentLeaseStateError is raised when the lease is in an inconsistent
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# state. This is usually indicative of a programming error, but not necessarily
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# one that affects all leases, so we just fail this lease. Note that Haizea can also
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# be configured to stop immediately when a lease fails.
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except InconsistentLeaseStateError, exc:
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self.fail_lease(lease, exc)
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# An EnactmentError is raised when the handler had to perform an enactment action
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# (e.g., stopping a VM), and that enactment action failed. This is currently treated
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# as a non-recoverable error for the lease, and the lease is failed.
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except EnactmentError, exc:
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self.fail_lease(lease, exc)
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# Other exceptions are not expected, and generally indicate a programming error.
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# Thus, they are propagated upwards to the Manager where they will make
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# Haizea crash and burn.
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get_persistence().persist_lease(lease) |
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def process_ending_reservations(self, nowtime): |
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"""Processes ending reservations
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This method checks the slottable to see if there are any reservations that are
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ending at "nowtime". If so, the appropriate handler is called.
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Arguments:
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nowtime -- Time at which to check for starting/ending reservations.
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"""
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# Find starting/ending reservations
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ending = self.slottable.get_reservations_ending_at(nowtime)
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ending = [res for res in ending if res.state == ResourceReservation.STATE_ACTIVE] |
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# Process ending reservations
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for rr in ending: |
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lease = rr.lease |
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self._handle_end_rr(rr)
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# Call the appropriate handler, and catch exceptions and errors.
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try:
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self.handlers[type(rr)].on_end(lease, rr) |
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# A RescheduleLeaseException indicates that the lease has to be rescheduled
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except RescheduleLeaseException, exc:
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# Currently, the only leases that get rescheduled are best-effort leases,
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# once they've been suspended.
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if rr.lease.get_type() == Lease.BEST_EFFORT:
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if lease.get_state() == Lease.STATE_SUSPENDED_PENDING:
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# Put back in the queue, in the same order it arrived
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self.__enqueue_in_order(lease)
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lease.set_state(Lease.STATE_SUSPENDED_QUEUED) |
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get_persistence().persist_queue(self.queue)
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else:
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raise InconsistentLeaseStateError(lease, doing = "rescheduling best-effort lease") |
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# A NormalEndLeaseException indicates that the end of this reservations marks
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# the normal end of the lease.
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except NormalEndLeaseException, msg:
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self._handle_end_lease(lease)
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# An InconsistentLeaseStateError is raised when the lease is in an inconsistent
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# state. This is usually indicative of a programming error, but not necessarily
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# one that affects all leases, so we just fail this lease. Note that Haizea can also
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# be configured to stop immediately when a lease fails.
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except InconsistentLeaseStateError, exc:
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self.fail_lease(lease, exc)
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# An EnactmentError is raised when the handler had to perform an enactment action
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# (e.g., stopping a VM), and that enactment action failed. This is currently treated
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# as a non-recoverable error for the lease, and the lease is failed.
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except EnactmentError, exc:
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self.fail_lease(lease, exc)
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# Other exceptions are not expected, and generally indicate a programming error.
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# Thus, they are propagated upwards to the Manager where they will make
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# Haizea crash and burn.
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get_persistence().persist_lease(lease) |
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def get_lease_by_id(self, lease_id): |
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"""Gets a lease with the given ID
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This method is useful for UIs (like the CLI) that operate on the lease ID.
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If no lease with a given ID is found, None is returned.
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Arguments:
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lease_id -- The ID of the lease
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"""
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if not self.leases.has_lease(lease_id): |
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return None |
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else:
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return self.leases.get_lease(lease_id) |
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def cancel_lease(self, lease): |
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"""Cancels a lease.
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Arguments:
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lease -- Lease to cancel
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"""
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time = get_clock().get_time() |
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self.logger.info("Cancelling lease %i..." % lease.id) |
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lease_state = lease.get_state() |
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if lease_state == Lease.STATE_PENDING:
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# If a lease is pending, we just need to change its state and
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# remove it from the lease table. Since this is done at the
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# end of this method, we do nothing here.
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pass
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elif lease_state == Lease.STATE_ACTIVE:
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# If a lease is active, that means we have to shut down its VMs to cancel it.
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self.logger.info("Lease %i is active. Stopping active reservation..." % lease.id) |
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vmrr = lease.get_active_vmrrs(time)[0]
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self._handle_end_rr(vmrr)
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self.vm_scheduler._handle_unscheduled_end_vm(lease, vmrr)
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# Force machines to shut down
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try:
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self.vm_scheduler.resourcepool.stop_vms(lease, vmrr)
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except EnactmentError, exc:
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self.logger.error("Enactment error when shutting down VMs.") |
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# Right now, this is a non-recoverable error, so we just
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# propagate it upwards.
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# In the future, it may be possible to react to these
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# kind of errors.
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raise
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elif lease_state in [Lease.STATE_SCHEDULED, Lease.STATE_SUSPENDED_SCHEDULED, Lease.STATE_READY, Lease.STATE_RESUMED_READY]: |
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# If a lease is scheduled or ready, we just need to cancel all future reservations
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# for that lease
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self.logger.info("Lease %i is scheduled. Cancelling reservations." % lease.id) |
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rrs = lease.get_scheduled_reservations() |
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for r in rrs: |
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self.slottable.remove_reservation(r)
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elif lease_state in [Lease.STATE_QUEUED, Lease.STATE_SUSPENDED_QUEUED]: |
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# If a lease is in the queue, waiting to be scheduled, cancelling
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# just requires removing it from the queue
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self.logger.info("Lease %i is in the queue. Removing..." % lease.id) |
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self.queue.remove_lease(lease)
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get_persistence().persist_queue(self.queue)
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else:
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# Cancelling in any of the other states is currently unsupported
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raise InconsistentLeaseStateError(lease, doing = "cancelling the VM") |
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# Change state, and remove from lease table
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lease.set_state(Lease.STATE_CANCELLED) |
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self.completed_leases.add(lease)
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self.leases.remove(lease)
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get_persistence().persist_lease(lease) |
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def fail_lease(self, lease, exc=None): |
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"""Transitions a lease to a failed state, and does any necessary cleaning up
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Arguments:
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lease -- Lease to fail
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exc -- The exception that made the lease fail
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"""
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treatment = get_config().get("lease-failure-handling")
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if treatment == constants.ONFAILURE_CANCEL:
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# In this case, a lease failure is handled by cancelling the lease,
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# but allowing Haizea to continue to run normally.
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rrs = lease.get_scheduled_reservations() |
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for r in rrs: |
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self.slottable.remove_reservation(r)
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lease.set_state(Lease.STATE_FAIL) |
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self.completed_leases.add(lease)
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self.leases.remove(lease)
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get_persistence().persist_lease(lease) |
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elif treatment == constants.ONFAILURE_EXIT or treatment == constants.ONFAILURE_EXIT_RAISE: |
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# In this case, a lease failure makes Haizea exit. This is useful when debugging,
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# so we can immediately know about any errors.
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raise UnrecoverableError(exc)
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def notify_event(self, lease, event): |
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"""Notifies an event that affects a lease.
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This is the entry point of asynchronous events into the scheduler. Currently,
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the only supported event is the premature end of a VM (i.e., before its
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scheduled end). Other events will emerge when we integrate Haizea with OpenNebula 1.4,
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since that version will support sending asynchronous events to Haizea.
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Arguments:
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lease -- Lease the event refers to
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event -- Event type
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"""
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time = get_clock().get_time() |
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if event == constants.EVENT_END_VM:
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vmrr = lease.get_vmrr_at(time) |
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vmrrs_after = lease.get_vmrr_after(time) |
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for vmrr_after in vmrrs_after: |
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for rr in vmrr_after.pre_rrs: |
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self.slottable.remove_reservation(rr)
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for rr in vmrr_after.post_rrs: |
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self.slottable.remove_reservation(rr)
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self.slottable.remove_reservation(vmrr_after)
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lease.remove_vmrr(vmrr_after) |
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self._handle_end_rr(vmrr)
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# TODO: Exception handling
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self.vm_scheduler._handle_unscheduled_end_vm(lease, vmrr)
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# We need to reevaluate the schedule to see if there are any
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# leases scheduled in the future that could be rescheduled
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# to start earlier
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nexttime = get_clock().get_next_schedulable_time() |
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self.reevaluate_schedule(nexttime, lease)
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self._handle_end_lease(lease)
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get_persistence().persist_lease(lease) |
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|
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def reevaluate_schedule(self, nexttime, ending_lease): |
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"""Reevaluates the schedule.
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450 |
|
451 |
This method can be called whenever resources are freed up
|
452 |
unexpectedly (e.g., a lease than ends earlier than expected))
|
453 |
to check if any leases scheduled in the future could be
|
454 |
rescheduled to start earlier on the freed up resources.
|
455 |
|
456 |
Currently, this method only checks if best-effort leases
|
457 |
scheduled in the future (using a backfilling algorithm)
|
458 |
can be rescheduled
|
459 |
|
460 |
Arguments:
|
461 |
nexttime -- The next time at which the scheduler can allocate resources.
|
462 |
"""
|
463 |
future = self.vm_scheduler.get_future_reschedulable_leases()
|
464 |
## BEGIN NOT-FIT-FOR-PRODUCTION CODE
|
465 |
## This is only necessary because we're currently using the best-effort
|
466 |
## scheduling algorithm for many of the deadline leases
|
467 |
future_best_effort = [l for l in future if l.get_type() == Lease.BEST_EFFORT] |
468 |
## END NOT-FIT-FOR-PRODUCTION CODE
|
469 |
for l in future_best_effort: |
470 |
# We can only reschedule leases in the following four states
|
471 |
# TODO: Leases in PREPARING state should be rescheduleable.
|
472 |
#if l.get_state() in (Lease.STATE_PREPARING, Lease.STATE_READY, Lease.STATE_SCHEDULED, Lease.STATE_SUSPENDED_SCHEDULED):
|
473 |
if l.get_state() in (Lease.STATE_READY, Lease.STATE_SCHEDULED, Lease.STATE_SUSPENDED_SCHEDULED): |
474 |
self.logger.debug("Rescheduling lease %i" % l.id) |
475 |
# For each reschedulable lease already scheduled in the
|
476 |
# future, we cancel the lease's preparation and
|
477 |
# the last scheduled VM.
|
478 |
if l.get_state() in (Lease.STATE_READY, Lease.STATE_SCHEDULED, Lease.STATE_PREPARING): |
479 |
self.preparation_scheduler.cancel_preparation(l)
|
480 |
l.set_state(Lease.STATE_PENDING) |
481 |
elif l.get_state() == Lease.STATE_SUSPENDED_SCHEDULED:
|
482 |
self.preparation_scheduler.cancel_preparation(l, remove_files = False) |
483 |
l.set_state(Lease.STATE_SUSPENDED_PENDING) |
484 |
|
485 |
vmrr = l.get_last_vmrr() |
486 |
self.vm_scheduler.cancel_vm(vmrr)
|
487 |
l.remove_vmrr(vmrr) |
488 |
|
489 |
# At this point, the lease just looks like a regular
|
490 |
# pending lease that can be handed off directly to the
|
491 |
# __schedule_lease method.
|
492 |
# TODO: We should do exception handling here. However,
|
493 |
# since we can only reschedule best-effort leases that were
|
494 |
# originally schedule in the future, the scheduling function
|
495 |
# should always be able to schedule the lease (worst-case
|
496 |
# scenario is that it simply replicates the previous schedule)
|
497 |
self.__schedule_lease(l, nexttime)
|
498 |
|
499 |
numnodes = ending_lease.numnodes |
500 |
freetime = ending_lease.duration.requested - ending_lease.duration.accumulated |
501 |
until = nexttime + freetime |
502 |
freecapacity = numnodes * freetime |
503 |
|
504 |
future_vmrrs = self.slottable.get_reservations_starting_after(nexttime)
|
505 |
future_vmrrs.sort(key=attrgetter("start"))
|
506 |
future_vmrrs = [rr for rr in future_vmrrs |
507 |
if isinstance(rr, VMResourceReservation) |
508 |
and rr.lease.get_type() == Lease.DEADLINE
|
509 |
and rr.lease.get_state() in (Lease.STATE_SCHEDULED, Lease.STATE_READY) |
510 |
and not rr.is_suspending() and not rr.is_resuming() |
511 |
and rr.start != rr.lease.start.requested]
|
512 |
|
513 |
leases = list(set([future_vmrr.lease for future_vmrr in future_vmrrs])) |
514 |
leases = [l for l in leases if l.numnodes <= numnodes |
515 |
and l.start.requested <= until
|
516 |
and l.duration.requested <= min(freetime, until - l.start.requested)] |
517 |
leases.sort(key= lambda l: (l.deadline - nexttime) / l.duration.requested)
|
518 |
self.logger.debug("Rescheduling future deadline leases") |
519 |
|
520 |
filled = DateTimeDelta(0)
|
521 |
for l in leases: |
522 |
dur = min(until - l.start.requested, l.duration.requested)
|
523 |
capacity = l.numnodes * dur |
524 |
|
525 |
if filled + capacity <= freecapacity:
|
526 |
# This lease might fit
|
527 |
self.logger.debug("Trying to reschedule lease %i" % l.id) |
528 |
self.slottable.push_state([l])
|
529 |
node_ids = self.slottable.nodes.keys()
|
530 |
earliest = {} |
531 |
for node in node_ids: |
532 |
earliest[node] = EarliestStartingTime(nexttime, EarliestStartingTime.EARLIEST_NOPREPARATION) |
533 |
|
534 |
for vmrr in [vmrr2 for vmrr2 in future_vmrrs if vmrr2.lease == l]: |
535 |
vmrr.lease.remove_vmrr(vmrr) |
536 |
self.vm_scheduler.cancel_vm(vmrr)
|
537 |
|
538 |
try:
|
539 |
origd = l.deadline |
540 |
l.deadline = until |
541 |
(new_vmrr, preemptions) = self.vm_scheduler.reschedule_deadline(l, dur, nexttime, earliest)
|
542 |
l.deadline = origd |
543 |
|
544 |
# Add VMRR to lease
|
545 |
l.append_vmrr(new_vmrr) |
546 |
|
547 |
# Add resource reservations to slottable
|
548 |
|
549 |
# Pre-VM RRs (if any)
|
550 |
for rr in new_vmrr.pre_rrs: |
551 |
self.slottable.add_reservation(rr)
|
552 |
|
553 |
# VM
|
554 |
self.slottable.add_reservation(new_vmrr)
|
555 |
|
556 |
# Post-VM RRs (if any)
|
557 |
for rr in new_vmrr.post_rrs: |
558 |
self.slottable.add_reservation(rr)
|
559 |
|
560 |
self.logger.debug("Rescheduled lease %i" % l.id) |
561 |
self.logger.vdebug("Lease after rescheduling:") |
562 |
l.print_contents() |
563 |
|
564 |
filled += capacity |
565 |
|
566 |
self.slottable.pop_state(discard=True) |
567 |
except NotSchedulableException:
|
568 |
l.deadline = origd |
569 |
self.logger.debug("Lease %i could not be rescheduled" % l.id) |
570 |
self.slottable.pop_state()
|
571 |
|
572 |
def is_queue_empty(self): |
573 |
"""Return True is the queue is empty, False otherwise"""
|
574 |
return self.queue.is_empty() |
575 |
|
576 |
|
577 |
def exists_scheduled_leases(self): |
578 |
"""Return True if there are any leases scheduled in the future"""
|
579 |
return not self.slottable.is_empty() |
580 |
|
581 |
|
582 |
def __process_queue(self, nexttime): |
583 |
""" Traverses the queue in search of leases that can be scheduled.
|
584 |
|
585 |
This method processes the queue in order, but takes into account that
|
586 |
it may be possible to schedule leases in the future (using a
|
587 |
backfilling algorithm)
|
588 |
|
589 |
Arguments:
|
590 |
nexttime -- The next time at which the scheduler can allocate resources.
|
591 |
"""
|
592 |
|
593 |
done = False
|
594 |
newqueue = Queue() |
595 |
while not done and not self.is_queue_empty(): |
596 |
if not self.vm_scheduler.can_schedule_in_future() and self.slottable.is_full(nexttime, restype = constants.RES_CPU): |
597 |
self.logger.debug("Used up all future reservations and slot table is full. Skipping rest of queue.") |
598 |
done = True
|
599 |
else:
|
600 |
lease = self.queue.dequeue()
|
601 |
try:
|
602 |
self.logger.info("Next request in the queue is lease %i. Attempting to schedule..." % lease.id) |
603 |
lease.print_contents() |
604 |
self.__schedule_lease(lease, nexttime)
|
605 |
except NotSchedulableException, msg:
|
606 |
# Put back on queue
|
607 |
newqueue.enqueue(lease) |
608 |
self.logger.info("Lease %i could not be scheduled at this time." % lease.id) |
609 |
if get_config().get("backfilling") == constants.BACKFILLING_OFF: |
610 |
done = True
|
611 |
|
612 |
for lease in self.queue: |
613 |
newqueue.enqueue(lease) |
614 |
|
615 |
self.queue = newqueue
|
616 |
|
617 |
|
618 |
def __schedule_lease(self, lease, nexttime): |
619 |
""" Schedules a lease.
|
620 |
|
621 |
This method orchestrates the preparation and VM scheduler to
|
622 |
schedule a lease.
|
623 |
|
624 |
Arguments:
|
625 |
lease -- Lease to schedule.
|
626 |
nexttime -- The next time at which the scheduler can allocate resources.
|
627 |
"""
|
628 |
|
629 |
lease_state = lease.get_state() |
630 |
migration = get_config().get("migration")
|
631 |
|
632 |
# Determine earliest start time in each node
|
633 |
if lease_state == Lease.STATE_PENDING or lease_state == Lease.STATE_QUEUED: |
634 |
# This lease might require preparation. Ask the preparation
|
635 |
# scheduler for the earliest starting time.
|
636 |
earliest = self.preparation_scheduler.find_earliest_starting_times(lease, nexttime)
|
637 |
elif lease_state == Lease.STATE_SUSPENDED_PENDING or lease_state == Lease.STATE_SUSPENDED_QUEUED: |
638 |
# This lease may have to be migrated.
|
639 |
# We have to ask both the preparation scheduler and the VM
|
640 |
# scheduler what would be the earliest possible starting time
|
641 |
# on each node, assuming we have to transfer files between
|
642 |
# nodes.
|
643 |
|
644 |
node_ids = self.slottable.nodes.keys()
|
645 |
earliest = {} |
646 |
if migration == constants.MIGRATE_NO:
|
647 |
# If migration is disabled, the earliest starting time
|
648 |
# is simply nexttime.
|
649 |
for node in node_ids: |
650 |
earliest[node] = EarliestStartingTime(nexttime, EarliestStartingTime.EARLIEST_NOPREPARATION) |
651 |
else:
|
652 |
# Otherwise, we ask the preparation scheduler and the VM
|
653 |
# scheduler how long it would take them to migrate the
|
654 |
# lease state.
|
655 |
prep_migr_time = self.preparation_scheduler.estimate_migration_time(lease)
|
656 |
vm_migr_time = self.vm_scheduler.estimate_migration_time(lease)
|
657 |
for node in node_ids: |
658 |
earliest[node] = EarliestStartingTime(nexttime + prep_migr_time + vm_migr_time, EarliestStartingTime.EARLIEST_MIGRATION) |
659 |
else:
|
660 |
raise InconsistentLeaseStateError(lease, doing = "scheduling a best-effort lease") |
661 |
|
662 |
# Now, we give the lease to the VM scheduler, along with the
|
663 |
# earliest possible starting times. If the VM scheduler can
|
664 |
# schedule VMs for this lease, it will return a resource reservation
|
665 |
# that we can add to the slot table, along with a list of
|
666 |
# leases that have to be preempted.
|
667 |
# If the VM scheduler can't schedule the VMs, it will throw an
|
668 |
# exception (we don't catch it here, and it is just thrown up
|
669 |
# to the calling method.
|
670 |
(vmrr, preemptions) = self.vm_scheduler.schedule(lease, lease.duration.get_remaining_duration(), nexttime, earliest)
|
671 |
|
672 |
## BEGIN NOT-FIT-FOR-PRODUCTION CODE
|
673 |
## Pricing shouldn't live here. Instead, it should happen before a lease is accepted
|
674 |
## It is being done here in the interest of developing a first prototype
|
675 |
## that incorporates pricing in simulations (but not interactively yet)
|
676 |
|
677 |
# Call pricing policy
|
678 |
lease_price = get_policy().price_lease(lease, preemptions) |
679 |
|
680 |
# Determine whether to accept price or not (this in particular
|
681 |
# should happen in the lease admission step)
|
682 |
if lease.extras.has_key("simul_userrate"): |
683 |
user_rate = float(lease.extras["simul_userrate"]) |
684 |
if get_config().get("policy.pricing") != "free": |
685 |
user_price = get_policy().pricing.get_base_price(lease, user_rate) |
686 |
# We want to record the rate at which the lease was priced
|
687 |
lease.extras["rate"] = get_policy().pricing.rate
|
688 |
if lease_price > user_price:
|
689 |
lease.price = -1
|
690 |
lease.extras["rejected_price"] = lease_price
|
691 |
raise NotSchedulableException, "Lease priced at %.2f. User is only willing to pay %.2f" % (lease_price, user_price) |
692 |
|
693 |
lease.price = lease_price |
694 |
## END NOT-FIT-FOR-PRODUCTION CODE
|
695 |
|
696 |
# Schedule lease preparation
|
697 |
is_ready = False
|
698 |
preparation_rrs = [] |
699 |
if lease_state in (Lease.STATE_SUSPENDED_PENDING, Lease.STATE_SUSPENDED_QUEUED) and migration != constants.MIGRATE_NO: |
700 |
# The lease might require migration
|
701 |
migr_rrs = self.preparation_scheduler.schedule_migration(lease, vmrr, nexttime)
|
702 |
if len(migr_rrs) > 0: |
703 |
end_migr = migr_rrs[-1].end
|
704 |
else:
|
705 |
end_migr = nexttime |
706 |
migr_rrs += self.vm_scheduler.schedule_migration(lease, vmrr, end_migr)
|
707 |
migr_rrs.reverse() |
708 |
for migr_rr in migr_rrs: |
709 |
vmrr.pre_rrs.insert(0, migr_rr)
|
710 |
if len(migr_rrs) == 0: |
711 |
is_ready = True
|
712 |
elif lease_state in (Lease.STATE_SUSPENDED_PENDING, Lease.STATE_SUSPENDED_QUEUED) and migration == constants.MIGRATE_NO: |
713 |
# No migration means the lease is ready
|
714 |
is_ready = True
|
715 |
elif lease_state in (Lease.STATE_PENDING, Lease.STATE_QUEUED): |
716 |
# The lease might require initial preparation
|
717 |
preparation_rrs, is_ready = self.preparation_scheduler.schedule(lease, vmrr, earliest, nexttime)
|
718 |
|
719 |
# If scheduling the lease involves preempting other leases,
|
720 |
# go ahead and preempt them.
|
721 |
if len(preemptions) > 0: |
722 |
self.logger.info("Must preempt leases %s to make room for lease #%i" % ([l.id for l in preemptions], lease.id)) |
723 |
for l in preemptions: |
724 |
self.__preempt_lease(l, preemption_time=vmrr.start)
|
725 |
|
726 |
# At this point, the lease is feasible.
|
727 |
# Commit changes by adding RRs to lease and to slot table
|
728 |
|
729 |
# Add preparation RRs (if any) to lease
|
730 |
for rr in preparation_rrs: |
731 |
lease.append_preparationrr(rr) |
732 |
|
733 |
# Add VMRR to lease
|
734 |
lease.append_vmrr(vmrr) |
735 |
|
736 |
|
737 |
# Add resource reservations to slottable
|
738 |
|
739 |
# Preparation RRs (if any)
|
740 |
for rr in preparation_rrs: |
741 |
self.slottable.add_reservation(rr)
|
742 |
|
743 |
# Pre-VM RRs (if any)
|
744 |
for rr in vmrr.pre_rrs: |
745 |
self.slottable.add_reservation(rr)
|
746 |
|
747 |
# VM
|
748 |
self.slottable.add_reservation(vmrr)
|
749 |
|
750 |
# Post-VM RRs (if any)
|
751 |
for rr in vmrr.post_rrs: |
752 |
self.slottable.add_reservation(rr)
|
753 |
|
754 |
# Change lease state
|
755 |
if lease_state == Lease.STATE_PENDING or lease_state == Lease.STATE_QUEUED: |
756 |
lease.set_state(Lease.STATE_SCHEDULED) |
757 |
if is_ready:
|
758 |
lease.set_state(Lease.STATE_READY) |
759 |
elif lease_state == Lease.STATE_SUSPENDED_PENDING or lease_state == Lease.STATE_SUSPENDED_QUEUED: |
760 |
lease.set_state(Lease.STATE_SUSPENDED_SCHEDULED) |
761 |
|
762 |
get_persistence().persist_lease(lease) |
763 |
|
764 |
lease.print_contents() |
765 |
|
766 |
|
767 |
def __preempt_lease(self, lease, preemption_time): |
768 |
""" Preempts a lease.
|
769 |
|
770 |
This method preempts a lease such that any resources allocated
|
771 |
to that lease after a given time are freed up. This may require
|
772 |
scheduling the lease to suspend before that time, or cancelling
|
773 |
the lease altogether.
|
774 |
|
775 |
Arguments:
|
776 |
lease -- Lease to schedule.
|
777 |
preemption_time -- Time at which lease must be preempted
|
778 |
"""
|
779 |
|
780 |
self.logger.info("Preempting lease #%i..." % (lease.id)) |
781 |
self.logger.vdebug("Lease before preemption:") |
782 |
lease.print_contents() |
783 |
vmrr = lease.get_last_vmrr() |
784 |
|
785 |
if vmrr.state == ResourceReservation.STATE_SCHEDULED and vmrr.start >= preemption_time: |
786 |
self.logger.debug("Lease was set to start in the middle of the preempting lease.") |
787 |
must_cancel_and_requeue = True
|
788 |
else:
|
789 |
susptype = get_config().get("suspension")
|
790 |
if susptype == constants.SUSPENSION_NONE:
|
791 |
must_cancel_and_requeue = True
|
792 |
else:
|
793 |
can_suspend = self.vm_scheduler.can_suspend_at(lease, preemption_time)
|
794 |
if not can_suspend: |
795 |
self.logger.debug("Suspending the lease does not meet scheduling threshold.") |
796 |
must_cancel_and_requeue = True
|
797 |
else:
|
798 |
if lease.numnodes > 1 and susptype == constants.SUSPENSION_SERIAL: |
799 |
self.logger.debug("Can't suspend lease because only suspension of single-node leases is allowed.") |
800 |
must_cancel_and_requeue = True
|
801 |
else:
|
802 |
self.logger.debug("Lease can be suspended") |
803 |
must_cancel_and_requeue = False
|
804 |
|
805 |
if must_cancel_and_requeue:
|
806 |
self.logger.info("... lease #%i has been cancelled and requeued." % lease.id) |
807 |
if lease.get_state() == Lease.STATE_SUSPENDED_SCHEDULED:
|
808 |
self.preparation_scheduler.cancel_preparation(lease, remove_files = False) |
809 |
else:
|
810 |
self.preparation_scheduler.cancel_preparation(lease)
|
811 |
self.vm_scheduler.cancel_vm(vmrr)
|
812 |
lease.remove_vmrr(vmrr) |
813 |
# TODO: Take into account other states
|
814 |
if lease.get_state() == Lease.STATE_SUSPENDED_SCHEDULED:
|
815 |
lease.set_state(Lease.STATE_SUSPENDED_QUEUED) |
816 |
else:
|
817 |
lease.set_state(Lease.STATE_QUEUED) |
818 |
self.__enqueue_in_order(lease)
|
819 |
else:
|
820 |
self.logger.info("... lease #%i will be suspended at %s." % (lease.id, preemption_time)) |
821 |
self.vm_scheduler.preempt_vm(vmrr, preemption_time)
|
822 |
|
823 |
get_persistence().persist_lease(lease) |
824 |
|
825 |
self.logger.vdebug("Lease after preemption:") |
826 |
lease.print_contents() |
827 |
|
828 |
def __enqueue(self, lease): |
829 |
"""Queues a best-effort lease request
|
830 |
|
831 |
Arguments:
|
832 |
lease -- Lease to be queued
|
833 |
"""
|
834 |
self.queue.enqueue(lease)
|
835 |
|
836 |
|
837 |
def __enqueue_in_order(self, lease): |
838 |
"""Queues a lease in order (currently, time of submission)
|
839 |
|
840 |
Arguments:
|
841 |
lease -- Lease to be queued
|
842 |
"""
|
843 |
self.queue.enqueue_in_order(lease)
|
844 |
|
845 |
|
846 |
def _handle_end_rr(self, rr): |
847 |
"""Performs actions that have to be done each time a reservation ends.
|
848 |
|
849 |
Arguments:
|
850 |
rr -- Reservation that ended
|
851 |
"""
|
852 |
self.slottable.remove_reservation(rr)
|
853 |
|
854 |
|
855 |
def _handle_end_lease(self, l): |
856 |
"""Performs actions that have to be done each time a lease ends.
|
857 |
|
858 |
Arguments:
|
859 |
lease -- Lease that has ended
|
860 |
"""
|
861 |
l.set_state(Lease.STATE_DONE) |
862 |
l.duration.actual = l.duration.accumulated |
863 |
l.end = round_datetime(get_clock().get_time()) |
864 |
if get_config().get("sanity-check"): |
865 |
if l.duration.known != None and l.duration.known < l.duration.requested: |
866 |
duration = l.duration.known |
867 |
else:
|
868 |
duration = l.duration.requested |
869 |
|
870 |
assert duration == l.duration.actual
|
871 |
|
872 |
if l.start.is_requested_exact():
|
873 |
assert l.vm_rrs[0].start >= l.start.requested |
874 |
if l.deadline != None: |
875 |
assert l.end <= l.deadline
|
876 |
|
877 |
self.preparation_scheduler.cleanup(l)
|
878 |
self.completed_leases.add(l)
|
879 |
self.leases.remove(l)
|
880 |
self.accounting.at_lease_done(l)
|
881 |
|
882 |
|
883 |
|
884 |
|
885 |
|
886 |
class Queue(object): |
887 |
"""A simple queue for leases
|
888 |
|
889 |
This class is a simple queue container for leases, with some
|
890 |
extra syntactic sugar added for convenience.
|
891 |
"""
|
892 |
|
893 |
def __init__(self): |
894 |
self.__q = []
|
895 |
|
896 |
def is_empty(self): |
897 |
return len(self.__q)==0 |
898 |
|
899 |
def enqueue(self, r): |
900 |
self.__q.append(r)
|
901 |
|
902 |
def dequeue(self): |
903 |
return self.__q.pop(0) |
904 |
|
905 |
def enqueue_in_order(self, r): |
906 |
self.__q.append(r)
|
907 |
self.__q.sort(key=attrgetter("submit_time")) |
908 |
|
909 |
def length(self): |
910 |
return len(self.__q) |
911 |
|
912 |
def has_lease(self, lease_id): |
913 |
return (1 == len([l for l in self.__q if l.id == lease_id])) |
914 |
|
915 |
def get_lease(self, lease_id): |
916 |
return [l for l in self.__q if l.id == lease_id][0] |
917 |
|
918 |
def remove_lease(self, lease): |
919 |
self.__q.remove(lease)
|
920 |
|
921 |
def __iter__(self): |
922 |
return iter(self.__q) |
923 |
|
924 |
class LeaseTable(object): |
925 |
"""A simple container for leases
|
926 |
|
927 |
This class is a simple dictionary-like container for leases, with some
|
928 |
extra syntactic sugar added for convenience.
|
929 |
"""
|
930 |
|
931 |
def __init__(self): |
932 |
self.entries = {}
|
933 |
|
934 |
def has_lease(self, lease_id): |
935 |
return self.entries.has_key(lease_id) |
936 |
|
937 |
def get_lease(self, lease_id): |
938 |
return self.entries[lease_id] |
939 |
|
940 |
def is_empty(self): |
941 |
return len(self.entries)==0 |
942 |
|
943 |
def remove(self, lease): |
944 |
del self.entries[lease.id] |
945 |
|
946 |
def add(self, lease): |
947 |
self.entries[lease.id] = lease
|
948 |
|
949 |
def get_leases(self, type=None): |
950 |
if type==None: |
951 |
return self.entries.values() |
952 |
else:
|
953 |
return [e for e in self.entries.values() if e.get_type() == type] |
954 |
|
955 |
def get_leases_by_state(self, state): |
956 |
return [e for e in self.entries.values() if e.get_state() == state] |
957 |
|
958 |
|