Package org.cloudbus.cloudsim.allocationpolicies

Class VmAllocationPolicySimple

java.lang.Object

org.cloudbus.cloudsim.allocationpolicies.VmAllocationPolicyAbstract

org.cloudbus.cloudsim.allocationpolicies.VmAllocationPolicySimple

All Implemented Interfaces:

VmAllocationPolicy

public class VmAllocationPolicySimple
extends VmAllocationPolicyAbstract

A VmAllocationPolicy implementation that chooses, as the host for a VM, that one with the fewest PEs in use. It is therefore a Worst Fit policy, allocating each VM into the host with most available PEs.

This is a really computationally complex policy since the worst-case complexity to allocate a Host for a VM is O(N), where N is the number of Hosts. Such an implementation is not appropriate for large scale scenarios.

NOTE: This policy doesn't perform optimization of VM allocation by means of VM migration.

Since:

CloudSim Toolkit 1.0

Author:

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

See Also:

• VmAllocationPolicyFirstFit
• VmAllocationPolicyBestFit

Field Summary

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

DEF_HOST_COUNT_PARALLEL_SEARCH, LOGGER, NULL

Constructor Summary

Constructors

Constructor	Description
VmAllocationPolicySimple()	Instantiates a VmAllocationPolicySimple.
VmAllocationPolicySimple(BiFunction<VmAllocationPolicy,Vm,Optional<Host>> findHostForVmFunction)	Instantiates a VmAllocationPolicySimple, changing the Function to select a Host for a Vm in order to define a different policy.

Method Summary

Modifier and Type	Method	Description
protected Optional<Host>	defaultFindHostForVm(Vm vm)	Gets the first suitable host from the VmAllocationPolicyAbstract.getHostList() that has the fewest number of used PEs (i.e, higher free PEs).

Methods inherited from class org.cloudbus.cloudsim.allocationpolicies.VmAllocationPolicyAbstract

allocateHostForVm, allocateHostForVm, allocateHostForVm, deallocateHostForVm, findHostForVm, getDatacenter, getHostCountForParallelSearch, getHostList, getOptimizedAllocationMap, isVmMigrationSupported, scaleVmVertically, setDatacenter, setFindHostForVmFunction, setHostCountForParallelSearch

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

VmAllocationPolicySimple

public VmAllocationPolicySimple()

Instantiates a VmAllocationPolicySimple.

VmAllocationPolicySimple

public VmAllocationPolicySimple(BiFunction<VmAllocationPolicy,Vm,Optional<Host>> findHostForVmFunction)

Instantiates a VmAllocationPolicySimple, changing the Function to select a Host for a Vm in order to define a different policy.

Parameters:

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

See Also:

• VmAllocationPolicy.setFindHostForVmFunction(java.util.function.BiFunction)

Method Details

defaultFindHostForVm

protected Optional<Host> defaultFindHostForVm(Vm vm)

Gets the first suitable host from the VmAllocationPolicyAbstract.getHostList() that has the fewest number of used PEs (i.e, higher free PEs).

Specified by:

defaultFindHostForVm in class VmAllocationPolicyAbstract

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 not found

See Also:

• VmAllocationPolicyAbstract.setFindHostForVmFunction(BiFunction)