terracotta/neat/locals/vm_selection/algorithms.py

129 lines
3.8 KiB
Python

# Copyright 2012 Anton Beloglazov
#
# 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.
""" VM selection algorithms.
"""
from contracts import contract
from neat.contracts_extra import *
from random import choice
import operator
import logging
log = logging.getLogger(__name__)
@contract
def random_factory(time_step, migration_time, params):
""" Creates the random VM selection algorithm.
:param time_step: The length of the simulation time step in seconds.
:type time_step: int,>=0
:param migration_time: The VM migration time in time seconds.
:type migration_time: float,>=0
:param params: A dictionary containing the algorithm's parameters.
:type params: dict(str: *)
:return: A function implementing the random VM selection algorithm.
:rtype: function
"""
return lambda vms_cpu, vms_ram, state=None: ([random(vms_cpu)], {})
@contract
def minimum_utilization_factory(time_step, migration_time, params):
""" Creates the minimum utilization VM selection algorithm.
:param time_step: The length of the simulation time step in seconds.
:type time_step: int,>=0
:param migration_time: The VM migration time in time seconds.
:type migration_time: float,>=0
:param params: A dictionary containing the algorithm's parameters.
:type params: dict(str: *)
:return: A function implementing the minimum utilization VM selection.
:rtype: function
"""
return lambda vms_cpu, vms_ram, state=None: \
([minimum_utilization(vms_cpu)], {})
@contract
def minimum_migration_time_factory(time_step, migration_time, params):
""" Creates the minimum migration time VM selection algorithm.
:param time_step: The length of the simulation time step in seconds.
:type time_step: int,>=0
:param migration_time: The VM migration time in time seconds.
:type migration_time: float,>=0
:param params: A dictionary containing the algorithm's parameters.
:type params: dict(str: *)
:return: A function implementing the minimum migration time VM selection.
:rtype: function
"""
return lambda vms_cpu, vms_ram, state=None: \
([minimum_migration_time(vms_ram)], {})
@contract
def minimum_migration_time(vms_ram):
""" Selects the VM with the minimum RAM usage.
:param vms_ram: A map of VM UUID and their RAM usage data.
:type vms_ram: dict(str: number)
:return: A VM to migrate from the host.
:rtype: str
"""
min_index, min_value = min(enumerate(vms_ram.values()),
key=operator.itemgetter(1))
return vms_ram.keys()[min_index]
@contract
def minimum_utilization(vms_cpu):
""" Selects the VM with the minimum CPU utilization.
:param vms_cpu: A map of VM UUID and their CPU utilization histories.
:type vms_cpu: dict(str: list)
:return: A VM to migrate from the host.
:rtype: str
"""
last_utilization = [x[-1] for x in vms_cpu.values()]
min_index, min_value = min(enumerate(last_utilization),
key=operator.itemgetter(1))
return vms_cpu.keys()[min_index]
@contract
def random(vms_cpu):
""" Selects a random VM.
:param vms_cpu: A map of VM UUID and their CPU utilization histories.
:type vms_cpu: dict(str: list)
:return: A VM to migrate from the host.
:rtype: str
"""
return choice(vms_cpu.keys())