Package org.cloudbus.cloudsim.allocationpolicies

Class VmAllocationPolicyAbstract

java.lang.Object

org.cloudbus.cloudsim.allocationpolicies.VmAllocationPolicyAbstract

All Implemented Interfaces:

VmAllocationPolicy

Direct Known Subclasses:

VmAllocationPolicyBestFit, VmAllocationPolicyFirstFit, VmAllocationPolicyMigrationAbstract, VmAllocationPolicyRandom, VmAllocationPolicyRoundRobin, VmAllocationPolicySimple, VmAllocationPolicyWorstFit

public abstract class VmAllocationPolicyAbstract
extends java.lang.Object
implements VmAllocationPolicy

An abstract class that represents the policy used by a Datacenter to choose a Host to place or migrate a given Vm. It supports two-stage commit of reservation of hosts: first, we reserve the Host and, once committed by the customer, the VM is effectively allocated to that Host.

Each Datacenter must to have its own instance of a VmAllocationPolicy.

Since:

CloudSim Toolkit 1.0

Author:

Rodrigo N. Calheiros, Anton Beloglazov, Manoel Campos da Silva Filho

Field Summary

Fields inherited from interface org.cloudbus.cloudsim.allocationpolicies.VmAllocationPolicy

DEF_HOST_COUNT_FOR_PARALLEL_SEARCH, NULL

Constructor Summary

Constructors

Constructor	Description
VmAllocationPolicyAbstract()	Creates a VmAllocationPolicy.
VmAllocationPolicyAbstract(java.util.function.BiFunction<VmAllocationPolicy,Vm,java.util.Optional<Host>> findHostForVmFunction)	Creates a VmAllocationPolicy, changing the BiFunction to select a Host for a Vm.

Method Summary

Modifier and Type	Method	Description
boolean	allocateHostForVm(Vm vm)	Allocates the host with less PEs in use for a given VM.
boolean	allocateHostForVm(Vm vm, Host host)	Allocates a specified host for a given Vm or VmGroup.
void	deallocateHostForVm(Vm vm)	Releases the host used by a VM.
protected abstract java.util.Optional<Host>	defaultFindHostForVm(Vm vm)	Provides the default implementation of the policy to find a suitable Host for a given VM.
java.util.Optional<Host>	findHostForVm(Vm vm)	Finds a suitable host that has enough resources to place a given VM.
Datacenter	getDatacenter()	Gets the Datacenter associated to the Allocation Policy.
int	getHostCountForParallelSearch()	Gets the minimum number of Hosts to start using parallel search.
<T extends Host> java.util.List<T>	getHostList()	Gets the list of Hosts available in a Datacenter, that will be used by the Allocation Policy to place VMs.
java.util.Map<Vm,Host>	getOptimizedAllocationMap(java.util.List<? extends Vm> vmList)	Gets a map of optimized allocation for VMs according to current utilization and Hosts under and overloaded conditions.
boolean	isVmMigrationSupported()	Checks if VM migrations are supported by this VmAllocationPolicy.
boolean	scaleVmVertically(VerticalVmScaling scaling)	Try to scale some Vm's resource vertically up or down, respectively if: the Vm is overloaded and the Host where the Vm is placed has enough capacity the Vm is underloaded The resource to be scaled is defined by the given VerticalVmScaling object.
void	setDatacenter(Datacenter datacenter)	Sets the Datacenter associated to the Allocation Policy
void	setFindHostForVmFunction(java.util.function.BiFunction<VmAllocationPolicy,Vm,java.util.Optional<Host>> findHostForVmFunction)	Sets a BiFunction that selects a Host for a given Vm.
void	setHostCountForParallelSearch(int hostCountForParallelSearch)	Sets the minimum number of Hosts to start using parallel search.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.cloudbus.cloudsim.allocationpolicies.VmAllocationPolicy

isParallelHostSearchEnabled

Constructor Details

VmAllocationPolicyAbstract

public VmAllocationPolicyAbstract()

Creates a VmAllocationPolicy.

VmAllocationPolicyAbstract

public VmAllocationPolicyAbstract(java.util.function.BiFunction<VmAllocationPolicy,Vm,java.util.Optional<Host>> findHostForVmFunction)

Creates a VmAllocationPolicy, changing the BiFunction to select a Host for a Vm.

Parameters:

findHostForVmFunction - a BiFunction to select a Host for a given Vm.

See Also:

VmAllocationPolicy.setFindHostForVmFunction(BiFunction)

Method Details

getHostList

public final <T extends Host> java.util.List<T> getHostList()

Description copied from interface: VmAllocationPolicy

Gets the list of Hosts available in a Datacenter, that will be used by the Allocation Policy to place VMs.

Specified by:

getHostList in interface VmAllocationPolicy

Type Parameters:

T - The generic type

Returns:

the host list

getDatacenter

public Datacenter getDatacenter()

Description copied from interface: VmAllocationPolicy

Gets the Datacenter associated to the Allocation Policy.

Specified by:

getDatacenter in interface VmAllocationPolicy

Returns:

setDatacenter

public final void setDatacenter(Datacenter datacenter)

Sets the Datacenter associated to the Allocation Policy

Specified by:

setDatacenter in interface VmAllocationPolicy

Parameters:

datacenter - the Datacenter to set

scaleVmVertically

public boolean scaleVmVertically(VerticalVmScaling scaling)

Description copied from interface: VmAllocationPolicy

Try to scale some Vm's resource vertically up or down, respectively if:

• the Vm is overloaded and the Host where the Vm is placed has enough capacity
• the Vm is underloaded

The resource to be scaled is defined by the given VerticalVmScaling object.

Specified by:

scaleVmVertically in interface VmAllocationPolicy

Parameters:

scaling - the VerticalVmScaling object with information of which resource is being requested to be scaled

Returns:

true if the requested resource was scaled, false otherwise

allocateHostForVm

public boolean allocateHostForVm(Vm vm)

Allocates the host with less PEs in use for a given VM.

Specified by:

allocateHostForVm in interface VmAllocationPolicy

Parameters:

vm - the Vm or VmGroup to allocate a host to

Returns:

true if the host could be allocated; false otherwise

See Also:

VmGroup

allocateHostForVm

public boolean allocateHostForVm(Vm vm, Host host)

Description copied from interface: VmAllocationPolicy

Allocates a specified host for a given Vm or VmGroup.

Specified by:

allocateHostForVm in interface VmAllocationPolicy

Parameters:

vm - the Vm or VmGroup to allocate a host to

host - the host to allocate to the given Vm or VmGroup

Returns:

true if the host could be allocated; false otherwise

See Also:

VmGroup

deallocateHostForVm

public void deallocateHostForVm(Vm vm)

Description copied from interface: VmAllocationPolicy

Releases the host used by a VM.

Specified by:

deallocateHostForVm in interface VmAllocationPolicy

Parameters:

vm - the vm to get its host released

setFindHostForVmFunction

public final void setFindHostForVmFunction(java.util.function.BiFunction<VmAllocationPolicy,Vm,java.util.Optional<Host>> findHostForVmFunction)

Sets a BiFunction that selects a Host for a given Vm. This Function receives the current VmAllocationPolicy and the Vm requesting to be place. It then returns an Optional<Host> that may contain a suitable Host for that Vm or not.

If not Function is set, the default VM selection method provided by implementing classes will be used.

The default implementation of such a Function is provided by the method findHostForVm(Vm).

Specified by:

setFindHostForVmFunction in interface VmAllocationPolicy

Parameters:

findHostForVmFunction - the BiFunction to set. Passing null makes the default method to find a Host for a VM to be used.

findHostForVm

public final java.util.Optional<Host> findHostForVm(Vm vm)

Description copied from interface: VmAllocationPolicy

Finds a suitable host that has enough resources to place a given VM. Internally it may use a default implementation or one set in runtime.

Specified by:

findHostForVm in interface VmAllocationPolicy

Parameters:

vm - the vm to find a host for it

Returns:

an Optional containing a suitable Host to place the VM or an empty Optional if no suitable Host was found

See Also:

VmAllocationPolicy.setFindHostForVmFunction(BiFunction)

defaultFindHostForVm

protected abstract java.util.Optional<Host> defaultFindHostForVm(Vm vm)

Provides the default implementation of the policy to find a suitable Host for a given VM.

Parameters:

vm - the VM to find a suitable Host to

Returns:

an Optional containing a suitable Host to place the VM or an empty Optional if no suitable Host was found

See Also:

setFindHostForVmFunction(BiFunction)

getOptimizedAllocationMap

public java.util.Map<Vm,Host> getOptimizedAllocationMap(java.util.List<? extends Vm> vmList)

Gets a map of optimized allocation for VMs according to current utilization and Hosts under and overloaded conditions. The conditions that will make a new VM placement map to be proposed and returned is defined by each implementing class.

This method implementation doesn't perform any VM placement optimization and, in fact, has no effect. Classes implementing the VmAllocationPolicyMigration provide actual implementations for this method that can be overridden by subclasses.

Specified by:

getOptimizedAllocationMap in interface VmAllocationPolicy

Parameters:

vmList - the list of VMs to be reallocated

Returns:

the new vm placement map, where each key is a VM and each value is the host where such a Vm has to be placed

getHostCountForParallelSearch

public int getHostCountForParallelSearch()

Description copied from interface: VmAllocationPolicy

Gets the minimum number of Hosts to start using parallel search.

Specified by:

getHostCountForParallelSearch in interface VmAllocationPolicy

Returns:

setHostCountForParallelSearch

public void setHostCountForParallelSearch(int hostCountForParallelSearch)

Description copied from interface: VmAllocationPolicy

Sets the minimum number of Hosts to start using parallel search.

Specified by:

setHostCountForParallelSearch in interface VmAllocationPolicy

Parameters:

hostCountForParallelSearch - the value to set (use Integer.MAX_VALUE to disable parallel search)

isVmMigrationSupported

public boolean isVmMigrationSupported()

Description copied from interface: VmAllocationPolicy

Checks if VM migrations are supported by this VmAllocationPolicy. Realize that even if the policy allows VM migration, such operations can be dynamically enabled/disabled by the Datacenter.

Specified by:

isVmMigrationSupported in interface VmAllocationPolicy

Returns:

See Also:

Datacenter.enableMigrations(), Datacenter.disableMigrations()