A CloudSim example using a VmAllocationPolicy and DatacenterBroker based in Round-Robin policy.

CloudSimExample9.java

package org.cloudbus.cloudsim.examples;

import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

import org.cloudbus.cloudsim.Cloudlet;
import org.cloudbus.cloudsim.CloudletSchedulerTimeShared;
import org.cloudbus.cloudsim.Datacenter;
import org.cloudbus.cloudsim.DatacenterBroker;
import org.cloudbus.cloudsim.DatacenterCharacteristics;
import org.cloudbus.cloudsim.Host;
import org.cloudbus.cloudsim.Log;
import org.cloudbus.cloudsim.Pe;
import org.cloudbus.cloudsim.Storage;
import org.cloudbus.cloudsim.UtilizationModel;
import org.cloudbus.cloudsim.UtilizationModelFull;
import org.cloudbus.cloudsim.Vm;
import org.cloudbus.cloudsim.VmSchedulerTimeShared;
import org.cloudbus.cloudsim.core.CloudSim;
import org.cloudbus.cloudsim.provisioners.BwProvisionerSimple;
import org.cloudbus.cloudsim.provisioners.PeProvisionerSimple;
import org.cloudbus.cloudsim.provisioners.RamProvisionerSimple;


public class CloudSimExample9 {

	/** The cloudlet list. */
	private static List<Cloudlet> cloudletList;

	/** The vmList. */
	private static List<Vm> vmList;

	private static List<Vm> createVM(int userId, int vms, int idShift) {
		//Creates a container to store VMs. This list is passed to the broker later
		LinkedList<Vm> list = new LinkedList<Vm>();

		//VM Parameters
		long size = 10000; //image size (MB)
		int ram = 512; //vm memory (MB)
		int mips = 250;
		long bw = 1000;
		int pesNumber = 1; //number of cpus
		String vmm = "Xen"; //VMM name

		//create VMs
		Vm[] vm = new Vm[vms];

		for(int i=0;i < vms;i++){
			vm[i] = new Vm(idShift + i, userId, mips, pesNumber, ram, bw, size, vmm, new CloudletSchedulerTimeShared());
			list.add(vm[i]);
		}

		return list;
	}


	private static List<Cloudlet> createCloudlet(int userId, int cloudlets, int idShift){
		// Creates a container to store Cloudlets
		LinkedList<Cloudlet> list = new LinkedList<Cloudlet>();

		//cloudlet parameters
		long length = 40000;
		long fileSize = 300;
		long outputSize = 300;
		int pesNumber = 1;
		UtilizationModel utilizationModel = new UtilizationModelFull();

		Cloudlet[] cloudlet = new Cloudlet[cloudlets];

		for(int i=0;i<cloudlets;i++){
			cloudlet[i] = new Cloudlet(idShift + i, length, pesNumber, fileSize, outputSize, utilizationModel, utilizationModel, utilizationModel);
			// setting the owner of these Cloudlets
			cloudlet[i].setUserId(userId);
			list.add(cloudlet[i]);
		}

		return list;
	}


	/**
	 * Creates main() to run this example
	 */
	public static void main(String[] args) {
		Log.printLine("Starting CloudSimExample8...");

		try {
			// First step: Initialize the CloudSim package. It should be called
			// before creating any entities.
			int num_user = 2;   // number of grid users
			Calendar calendar = Calendar.getInstance();
			boolean trace_flag = false;  // mean trace events

			// Initialize the CloudSim library
			CloudSim.init(num_user, calendar, trace_flag);

			//GlobalBroker globalBroker = new GlobalBroker("GlobalBroker");

			// Second step: Create Datacenters
			//Datacenters are the resource providers in CloudSim. We need at list one of them to run a CloudSim simulation
			Datacenter datacenter0 = createDatacenter("Datacenter_0");
			Datacenter datacenter1 = createDatacenter("Datacenter_1");

			//Third step: Create Broker
			DatacenterBroker broker = createBroker("Broker_0");
			int brokerId = broker.getId();

			//Fourth step: Create VMs and Cloudlets and send them to broker
			vmList = createVM(brokerId, 5, 0); //creating 5 vms
			cloudletList = createCloudlet(brokerId, 10, 0); // creating 10 cloudlets

			broker.submitVmList(vmList);
			broker.submitCloudletList(cloudletList);

			// Fifth step: Starts the simulation
			CloudSim.startSimulation();

			// Final step: Print results when simulation is over
			List<Cloudlet> newList = broker.getCloudletReceivedList();
			//newList.addAll(globalBroker.getBroker().getCloudletReceivedList());

			CloudSim.stopSimulation();

			printCloudletList(newList);

			//Print the debt of each user to each datacenter
			datacenter0.printDebts();
			datacenter1.printDebts();

			Log.printLine(CloudSimExample9.class.getName() + " finished!");
		}
		catch (Exception e)
		{
			e.printStackTrace();
			Log.printLine("The simulation has been terminated due to an unexpected error");
		}
	}

	private static Datacenter createDatacenter(String name){

		// Here are the steps needed to create a PowerDatacenter:
		// 1. We need to create a list to store one or more
		//    Machines
		List<Host> hostList = new ArrayList<Host>();

		// 2. A Machine contains one or more PEs or CPUs/Cores. Therefore, should
		//    create a list to store these PEs before creating
		//    a Machine.
		List<Pe> peList1 = new ArrayList<Pe>();

		int mips = 1000;

		// 3. Create PEs and add these into the list.
		//for a quad-core machine, a list of 4 PEs is required:
		peList1.add(new Pe(0, new PeProvisionerSimple(mips))); // need to store Pe id and MIPS Rating
		peList1.add(new Pe(1, new PeProvisionerSimple(mips)));
		peList1.add(new Pe(2, new PeProvisionerSimple(mips)));
		peList1.add(new Pe(3, new PeProvisionerSimple(mips)));

		//Another list, for a dual-core machine
		List<Pe> peList2 = new ArrayList<Pe>();

		peList2.add(new Pe(0, new PeProvisionerSimple(mips)));
		peList2.add(new Pe(1, new PeProvisionerSimple(mips)));

		//4. Create Hosts with its id and list of PEs and add them to the list of machines
		int hostId=0;
		int ram = 16384; //host memory (MB)
		long storage = 1000000; //host storage
		int bw = 10000;

		hostList.add(
    			new Host(
    				hostId,
    				new RamProvisionerSimple(ram),
    				new BwProvisionerSimple(bw),
    				storage,
    				peList1,
    				new VmSchedulerTimeShared(peList1)
    			)
    		); // This is our first machine

		hostId++;

		hostList.add(
    			new Host(
    				hostId,
    				new RamProvisionerSimple(ram),
    				new BwProvisionerSimple(bw),
    				storage,
    				peList2,
    				new VmSchedulerTimeShared(peList2)
    			)
    		); // Second machine

		// 5. Create a DatacenterCharacteristics object that stores the
		//    properties of a data center: architecture, OS, list of
		//    Machines, allocation policy: time- or space-shared, time zone
		//    and its price (G$/Pe time unit).
		String arch = "x86";      // system architecture
		String os = "Linux";          // operating system
		String vmm = "Xen";
		double time_zone = 10.0;         // time zone this resource located
		double cost = 3.0;              // the cost of using processing in this resource
		double costPerMem = 0.05;		// the cost of using memory in this resource
		double costPerStorage = 0.1;	// the cost of using storage in this resource
		double costPerBw = 0.1;			// the cost of using bw in this resource
		LinkedList<Storage> storageList = new LinkedList<Storage>();	//we are not adding SAN devices by now

		DatacenterCharacteristics characteristics = new DatacenterCharacteristics(
                arch, os, vmm, hostList, time_zone, cost, costPerMem, costPerStorage, costPerBw);


		// 6. Finally, we need to create a PowerDatacenter object.
		Datacenter datacenter = null;
		try {
			RoundRobinVmAllocationPolicy vm_policy = new RoundRobinVmAllocationPolicy(hostList);
			datacenter = new Datacenter(name, characteristics, vm_policy, storageList, 0);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return datacenter;
	}
	

	public static class VmAllocationPolicyMinimum extends org.cloudbus.cloudsim.VmAllocationPolicy {

		private Map<String, Host> vm_table = new HashMap<String, Host>();
		
		private final Hosts hosts;
		private Datacenter datacenter;

		public VmAllocationPolicyMinimum(List<? extends Host> list) {
			super(list);
			hosts = new Hosts(list);
		}
		
		public void setDatacenter(Datacenter datacenter) {
			this.datacenter = datacenter;
		}
		
		public Datacenter getDatacenter() {
			return datacenter;
		}

		@Override
		public boolean allocateHostForVm(Vm vm) {

			if (this.vm_table.containsKey(vm.getUid()))
				return true;

			boolean vm_allocated = false;
			int tries = 0;
			
			do 
			{
				Host host = this.hosts.getWithMinimumNumberOfPesEquals(vm.getNumberOfPes());
				vm_allocated = this.allocateHostForVm(vm, host);
				
			} while (!vm_allocated && tries++ < hosts.size());

			return vm_allocated;
		}

		@Override
		public boolean allocateHostForVm(Vm vm, Host host) 
		{
			if (host != null && host.vmCreate(vm)) 
			{
				vm_table.put(vm.getUid(), host);
				Log.formatLine("%.4f: VM #" + vm.getId() + " has been allocated to the host#" + host.getId() + 
						" datacenter #" + host.getDatacenter().getId() + "(" + host.getDatacenter().getName() + ") #", 
						CloudSim.clock());
				return true;
			}
			return false;
		}

		@Override
		public List<Map<String, Object>> optimizeAllocation(List<? extends Vm> vmList) {
			return null;
		}

		@Override
		public void deallocateHostForVm(Vm vm) {
			Host host = this.vm_table.remove(vm.getUid());
			
			if (host != null)
			{
				host.vmDestroy(vm);
			}
		}

		@Override
		public Host getHost(Vm vm) {
			return this.vm_table.get(vm.getUid());
		}

		@Override
		public Host getHost(int vmId, int userId) {
			return this.vm_table.get(Vm.getUid(userId, vmId));
		}
	}

	
	private static DatacenterBroker createBroker(String name) throws Exception{
		return new RoundRobinDatacenterBroker(name);
	}

	/**
	 * Prints the Cloudlet objects
	 * @param list  list of Cloudlets
	 */
	private static void printCloudletList(List<Cloudlet> list) {
		int size = list.size();
		Cloudlet cloudlet;

		String indent = "    ";
		Log.printLine();
		Log.printLine("========== OUTPUT ==========");
		Log.printLine("Cloudlet ID" + indent + "STATUS" + indent +
				"Data center ID" + indent + "VM ID" + indent + indent + "Time" + indent + "Start Time" + indent + "Finish Time");

		DecimalFormat dft = new DecimalFormat("###.##");
		for (int i = 0; i < size; i++) {
			cloudlet = list.get(i);
			Log.print(indent + cloudlet.getCloudletId() + indent + indent);

			if (cloudlet.getCloudletStatus() == Cloudlet.SUCCESS){
				Log.print("SUCCESS");

				Log.printLine( indent + indent + cloudlet.getResourceId() + indent + indent + indent + cloudlet.getVmId() +
						indent + indent + indent + dft.format(cloudlet.getActualCPUTime()) +
						indent + indent + dft.format(cloudlet.getExecStartTime())+ indent + indent + indent + dft.format(cloudlet.getFinishTime()));
			}
		}
	}
}