Class VmAllocationPolicyAbstract

java.lang.Object

org.cloudsimplus.allocationpolicies.VmAllocationPolicyAbstract

All Implemented Interfaces:

VmAllocationPolicy

Direct Known Subclasses:

VmAllocationPolicyBestFit, VmAllocationPolicyFirstFit, VmAllocationPolicyMigrationAbstract, VmAllocationPolicyRandom, VmAllocationPolicyRoundRobin, VmAllocationPolicySimple

public abstract class VmAllocationPolicyAbstract
extends 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.

Each Datacenter must 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.cloudsimplus.allocationpolicies.VmAllocationPolicy

DEF_HOST_COUNT_PARALLEL_SEARCH, LOGGER, NULL

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
final Set<HostSuitability>	allocateHostForVm(@NonNull List<Vm> vmList)	Tries to allocate a host for a each Vm or VmGroup into a given List.
HostSuitability	allocateHostForVm(Vm vm)	Allocates the host with less PEs in use for a given VM.
HostSuitability	allocateHostForVm(Vm vm, Host host)	Tries to allocate a specified host for a given Vm or VmGroup.
protected Set<HostSuitability>	allocateHostForVmInternal(@NonNull List<Vm> vmList)	If you override this method, you must call allocateHostForVm(Vm, Host) for each suitable Host you have found that want to create a VM.
void	deallocateHostForVm(Vm vm)	Releases the host used by a VM.
protected abstract Optional<Host>	defaultFindHostForVm(Vm vm)	Provides the default implementation of the policy to find a suitable Host for a given VM.
final Optional<Host>	findHostForVm(Vm vm)	Finds a suitable Host that has enough resources to place a given VM.
final <T extends Host> List<T>	getHostList()	Gets the list of Hosts available in the Datacenter linked to this VmAllocationPolicy, which will be used to place VMs.
Map<Vm,Host>	getOptimizedAllocationMap(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.
final VmAllocationPolicy	setFindHostForVmFunction(BiFunction<VmAllocationPolicy, Vm, Optional<Host>> findHostForVmFunction)	Sets a BiFunction that selects a Host for a given Vm.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.cloudsimplus.allocationpolicies.VmAllocationPolicy

getDatacenter, getHostCountForParallelSearch, isParallelHostSearchEnabled, setDatacenter, setHostCountForParallelSearch

Constructor Details

VmAllocationPolicyAbstract

public VmAllocationPolicyAbstract()

Creates a VmAllocationPolicy.

VmAllocationPolicyAbstract

public VmAllocationPolicyAbstract(BiFunction<VmAllocationPolicy, Vm, 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> List<T> getHostList()

Description copied from interface: VmAllocationPolicy

Gets the list of Hosts available in the Datacenter linked to this VmAllocationPolicy, which will be used to place VMs.

Specified by:

getHostList in interface VmAllocationPolicy

Type Parameters:

T - the host type

Returns:

datacenter the host list

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 final Set<HostSuitability> allocateHostForVm(@NonNull
 @NonNull List<Vm> vmList)

Description copied from interface: VmAllocationPolicy

Tries to allocate a host for a each Vm or VmGroup into a given List. The method should define how it will find a suitable Host for each Vm and then call VmAllocationPolicy.allocateHostForVm(Vm, Host) to actually create the VM inside the selected Host.

Specified by:

allocateHostForVm in interface VmAllocationPolicy

Parameters:

vmList - the List of Vms or VmGroups to allocate a host to

Returns:

a Set of HostSuitability to indicate if a Vm was placed into the host or not, containing a HostSuitability object for the last Host where each VM was tried to be created; or an empty set if the Datacenter has no hosts.

See Also:

• VmGroup

allocateHostForVmInternal

protected Set<HostSuitability> allocateHostForVmInternal(@NonNull
 @NonNull List<Vm> vmList)

If you override this method, you must call allocateHostForVm(Vm, Host) for each suitable Host you have found that want to create a VM.

See Also:

• allocateHostForVm(List)
• Host.getSuitabilityFor(Vm)

allocateHostForVm

public HostSuitability allocateHostForVm(Vm vm)

Allocates the host with less PEs in use for a given VM. Tries to allocate a host for a given Vm or VmGroup.

Specified by:

allocateHostForVm in interface VmAllocationPolicy

Parameters:

vm - the Vm or VmGroup to allocate a host to

Returns:

a HostSuitability to indicate if the Vm was placed into the host or not (if the Host doesn't have enough resources to allocate the Vm)

See Also:

• VmGroup

allocateHostForVm

public HostSuitability allocateHostForVm(Vm vm,
 Host host)

Description copied from interface: VmAllocationPolicy

Tries to allocate 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:

a HostSuitability to indicate if the Vm was placed into the host or not (if the Host doesn't have enough resources to allocate the Vm)

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 VmAllocationPolicy setFindHostForVmFunction(BiFunction<VmAllocationPolicy, Vm, 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 placed. It then returns an Optional<Host> that may contain a suitable Host for that Vm or not.

If no Function is set, the default VM selection method provided by implementing classes will be used instead.

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 will cause the usage of the default method to find a Host for a VM.

See Also:

• defaultFindHostForVm(Vm)

findHostForVm

public final 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

defaultFindHostForVm

protected abstract 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 Map<Vm,Host> getOptimizedAllocationMap(List<? extends Vm> vmList)

Description copied from interface: VmAllocationPolicy

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.

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

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:

true if VM migration is supported; false otherwise.

See Also:

• Datacenter.enableMigrations()
• Datacenter.disableMigrations()