86 lines
3.6 KiB
Python
86 lines
3.6 KiB
Python
# Copyright (c) 2014 Cisco Systems Inc.
|
|
# All Rights Reserved.
|
|
#
|
|
# 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.
|
|
|
|
|
|
from oslo.config import cfg
|
|
|
|
from nova.scheduler.solvers import linearconstraints
|
|
|
|
CONF = cfg.CONF
|
|
CONF.import_opt('ram_allocation_ratio', 'nova.scheduler.filters.ram_filter')
|
|
|
|
|
|
class MaxRamAllocationPerHostConstraint(
|
|
linearconstraints.ResourceAllocationConstraint):
|
|
"""Constraint of the total ram demand acceptable on each host."""
|
|
|
|
# The linear constraint should be formed as:
|
|
# coeff_vectors * var_vectors' (operator) (constants)
|
|
# where (operator) is ==, >, >=, <, <=, !=, etc.
|
|
# For convenience, the (constants) is merged into left-hand-side,
|
|
# thus the right-hand-side is 0.
|
|
|
|
def get_coefficient_vectors(self, variables, hosts, instance_uuids,
|
|
request_spec, filter_properties):
|
|
# Give demand as coefficient for each variable and -supply as constant
|
|
# in each constraint.
|
|
[num_hosts, num_instances] = self._get_host_instance_nums(hosts,
|
|
instance_uuids, request_spec)
|
|
demand = [self._get_required_memory_mb(filter_properties)
|
|
for j in range(self.num_instances)]
|
|
supply = [self._get_usable_memory_mb(hosts[i])
|
|
for i in range(self.num_hosts)]
|
|
coefficient_vectors = [demand + [-supply[i]]
|
|
for i in range(self.num_hosts)]
|
|
return coefficient_vectors
|
|
|
|
def get_variable_vectors(self, variables, hosts, instance_uuids,
|
|
request_spec, filter_properties):
|
|
# The variable_vectors[i,j] denotes the relationship between host[i]
|
|
# and instance[j].
|
|
variable_vectors = []
|
|
variable_vectors = [[variables[i][j]
|
|
for j in range(self.num_instances)]
|
|
+ [1] for i in range(self.num_hosts)]
|
|
return variable_vectors
|
|
|
|
def get_operations(self, variables, hosts, instance_uuids, request_spec,
|
|
filter_properties):
|
|
# Operations are '<='.
|
|
operations = [(lambda x: x <= 0) for i in range(self.num_hosts)]
|
|
return operations
|
|
|
|
def _get_usable_memory_mb(self, host_state):
|
|
"""This method returns the usable memory in mb for the given host.
|
|
Takes into account the ram allocation ratio (Virtual ram to
|
|
physical ram allocation ratio)
|
|
"""
|
|
free_ram_mb = host_state.free_ram_mb
|
|
total_usable_ram_mb = host_state.total_usable_ram_mb
|
|
memory_mb_limit = total_usable_ram_mb * CONF.ram_allocation_ratio
|
|
used_ram_mb = total_usable_ram_mb - free_ram_mb
|
|
usable_ram_mb = memory_mb_limit - used_ram_mb
|
|
return usable_ram_mb
|
|
|
|
def _get_required_memory_mb(self, filter_properties):
|
|
"""This method returns the required memory in mb from
|
|
the given filter_properties dictionary object.
|
|
"""
|
|
required_ram_mb = 0
|
|
instance_type = filter_properties.get('instance_type')
|
|
if instance_type is not None:
|
|
required_ram_mb = instance_type.get('memory_mb', 0)
|
|
return required_ram_mb
|