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
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. 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

  • Constructor Details

  • Method Details

    • getHostList

      public final <T extends Host> 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 VmAllocationPolicy.
      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 HostSuitability 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:
      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:

    • allocateHostForVm

      public <T extends Vm> List<T> allocateHostForVm(Collection<T> vmCollection)
      Description copied from interface: VmAllocationPolicy
      Tries to allocate hosts for a collection of Vms or VmGroups.
      Specified by:
      allocateHostForVm in interface VmAllocationPolicy
      Parameters:
      vmCollection - the Vm or VmGroup collection to allocate hosts to
      Returns:
      an empty list if hosts were allocated to all VMs or a list of Vms that a suitable host couldn't be found.
      See Also:

    • 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:

    • 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(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 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 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:

    • 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:

    • getOptimizedAllocationMap

      public 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. 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: