why it returns worng performance metrics

[Ghetas]

hello every one
I am trying to collect performance metrics for CPU using the below code. the code is running without error but the performance metrics values i got from the code is completely different when it is compared with the values from top command

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import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.virtualbox_5_0.Holder;
import org.virtualbox_5_0.IMachine;
import org.virtualbox_5_0.IPerformanceCollector;
import org.virtualbox_5_0.IUnknown;
import org.virtualbox_5_0.IVirtualBox;
import org.virtualbox_5_0.VBoxException;
import org.virtualbox_5_0.VirtualBoxManager;


public class VmIPerformanceCollector {
	IVirtualBox vbox;
	IMachine machine;
	IPerformanceCollector oCollector;
	VirtualBoxManager mgr;
	String machinename;

	long scale;
	double Cpuutilization;
	
	public VmIPerformanceCollector(String machinename){
		this.machinename=machinename;
		
	}
	@SuppressWarnings("finally")
	public boolean ConnecttoVirtualbox(){
		boolean connectsucess=false;
		mgr = VirtualBoxManager.createInstance(null);
		try{
			mgr.connect(vm.getVboxsrvUrl(), null, null);
			vbox=mgr.getVBox();
			machine=vbox.findMachine(machinename);
			
		}catch (VBoxException e){
			e.printStackTrace();
		}finally{
		return connectsucess;
		}
	}
	
	public void setup(long Period, long Count){
		 oCollector = vbox.getPerformanceCollector();
         oCollector.setupMetrics(Arrays.asList(new String[]{"CPU/*:avg"}),
                 new ArrayList<IUnknown>(),
                 Period, Count);
	}

	public void CollectCpuUtilization(long time) throws InterruptedException{
		

        Holder<List<String>> names = new Holder<List<String>> ();
        Holder<List<IUnknown>> objects = new Holder<List<IUnknown>>() ;
        Holder<List<String>> units = new Holder<List<String>>();
        Holder<List<Long>> scales =  new Holder<List<Long>>();
        Holder<List<Long>> sequenceNumbers =  new Holder<List<Long>>();
        Holder<List<Long>> indices =  new Holder<List<Long>>();
        Holder<List<Long>> lengths =  new Holder<List<Long>>();
        oCollector = vbox.getPerformanceCollector();         

        List<Integer> values = oCollector.queryMetricsData(Arrays.asList(new String[]{"CPU/*:avg"}),
                Arrays.asList(new IUnknown[]{machine}),
                names, objects, units, scales,
                sequenceNumbers, indices, lengths);
        Cpuutilization=0;
        System.out.println();
        for (int i=0; i < names.value.size(); i++){
        		scale=scales.value.get(i);
        		System.out.println(names.value.get(i));
                for (int j = 0; j < lengths.value.get(i); j++)
                {
                    long val= values.get(indices.value.get(i).intValue() + j).longValue();
                    System.out.println(val);
                    Long val2=val;
                }
        }

        System.out.println("------------------");
        disconnect();
        
	}
	
	public void disconnect(){
        try {
            mgr.disconnect();
        } catch (VBoxException e) {
        	e.printStackTrace();
			safeprinterr.safeprintErr(e.getMessage());
			safePrintln.safeprintln("Cannot disconnect, start webserver first!");
        }
        mgr.cleanup();
	}

}

and i call the VmIPerformanceCollector from the main

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public class testcpuperformance {
	
	public static void main(String[] args) throws InterruptedException{
		
		String VmName="VmLab11";

		VmIPerformanceCollector vmper=new VmIPerformanceCollector(VmName);
		vmper.ConnecttoVirtualbox();
		vmper.setup(new Long(1), new Long(3));
		vmper.disconnect();
		for(int i=1; i<100; i++){
			Thread.sleep(2000);
			vmper.ConnecttoVirtualbox();
			
			vmper.CollectCpuUtilization(3);
		}
	}
}

and the output is

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CPU/Load/User
250
375
CPU/Load/Kernel
250
250
------------------

CPU/Load/User
375
250
125
CPU/Load/Kernel
250
125
250
------------------

the performance values are completely different from that i got using the top commands

i am using
Centos 6.7
Virtualbox 5.0.12
Language Java (jdk 1.7)

any help will be appreciated

[noteirak]

Nothing looks wrong to me, you do get values back.
If you are concerned about the values themselves, the CPU Load per example would be from 0 to 100 per CPU configured in the VM. so if you have 4 CPU all running at 50%, you'll get a load of 200.

[noteirak]

Actually, checking the doc again to be sure, here is the meaning of CPU/Load:

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CPU/Load/User        %             0     100000          0          0 Percentage of processor time spent in user mode by the VM process.

If you want a full list of metrics and their meaning, via the API: IPerformanceCollector::metrics and then ::getMetrics() on each and finally IPerformanceMetric::getDescription()

via vboxmanage:

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vboxmanage metrics list

[Ghetas]

Nothing looks wrong to me, you do get values back.
If you are concerned about the values themselves, the CPU Load per example would be from 0 to 100 per CPU configured in the VM. so if you have 4 CPU all running at 50%, you'll get a load of 200.

thanks noteirak
now i update my code to display metric name, unit and scale as indicated by the comments

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    import java.util.ArrayList;
    import java.util.Arrays;
    import java.util.List;
    import org.virtualbox_5_0.Holder;
    import org.virtualbox_5_0.IMachine;
    import org.virtualbox_5_0.IPerformanceCollector;
    import org.virtualbox_5_0.IUnknown;
    import org.virtualbox_5_0.IVirtualBox;
    import org.virtualbox_5_0.VBoxException;
    import org.virtualbox_5_0.VirtualBoxManager;


    public class VmIPerformanceCollector {
       IVirtualBox vbox;
       IMachine machine;
       IPerformanceCollector oCollector;
       VirtualBoxManager mgr;
       String machinename;

       long scale;
       double Cpuutilization;
       
       public VmIPerformanceCollector(String machinename){
          this.machinename=machinename;
          
       }
       @SuppressWarnings("finally")
       public boolean ConnecttoVirtualbox(){
          boolean connectsucess=false;
          mgr = VirtualBoxManager.createInstance(null);
          try{
             mgr.connect(vm.getVboxsrvUrl(), null, null);
             vbox=mgr.getVBox();
             machine=vbox.findMachine(machinename);
             
          }catch (VBoxException e){
             e.printStackTrace();
          }finally{
          return connectsucess;
          }
       }
       
       public void setup(long Period, long Count){
           oCollector = vbox.getPerformanceCollector();
             oCollector.setupMetrics(Arrays.asList(new String[]{"CPU/*:avg"}),
                     new ArrayList<IUnknown>(),
                     Period, Count);
       }

       public void CollectCpuUtilization(long time) throws InterruptedException{
          

            Holder<List<String>> names = new Holder<List<String>> ();
            Holder<List<IUnknown>> objects = new Holder<List<IUnknown>>() ;
            Holder<List<String>> units = new Holder<List<String>>();
            Holder<List<Long>> scales =  new Holder<List<Long>>();
            Holder<List<Long>> sequenceNumbers =  new Holder<List<Long>>();
            Holder<List<Long>> indices =  new Holder<List<Long>>();
            Holder<List<Long>> lengths =  new Holder<List<Long>>();
            oCollector = vbox.getPerformanceCollector();         

            List<Integer> values = oCollector.queryMetricsData(Arrays.asList(new String[]{"CPU/*:avg"}),
                    Arrays.asList(new IUnknown[]{machine}),
                    names, objects, units, scales,
                    sequenceNumbers, indices, lengths);
            Cpuutilization=0;
            System.out.println();
           // new updated part
            for (int i=0; i < names.value.size(); i++){
                 scale=scales.value.get(i);
                  System.out.println(names.value.get(i));
        		System.out.println("Metric Name: "+names.value.get(i));
        		System.out.println("Scale: "+scales.value.get(i));
        		System.out.println("unit: "+units.value.get(i));
        		scale=scales.value.get(i);
                for (int j = 0; j < lengths.value.get(i); j++)
                {
                    long val= values.get(indices.value.get(i).intValue() + j).longValue();
                    System.out.println("value: "+ val); 
                }
            }

            System.out.println("------------------");
            disconnect();
           
       }
       
       public void disconnect(){
            try {
                mgr.disconnect();
            } catch (VBoxException e) {
               e.printStackTrace();
             safeprinterr.safeprintErr(e.getMessage());
             safePrintln.safeprintln("Cannot disconnect, start webserver first!");
            }
            mgr.cleanup();
       }

    }

i update testcpuperformance class to get the metric one time

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    public class testcpuperformance {
       
       public static void main(String[] args) throws InterruptedException{
          
          String VmName="VmLab11";

          VmIPerformanceCollector vmper=new VmIPerformanceCollector(VmName);
          vmper.ConnecttoVirtualbox();
          vmper.setup(new Long(1), new Long(3));
          vmper.disconnect();

             Thread.sleep(2000);
             vmper.ConnecttoVirtualbox();
             
             vmper.CollectCpuUtilization(3);

       }
    }

the output results from the running is

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Metric Name: CPU/Load/User:avg
Scale: 1000
unit: %
value: 66
Metric Name: CPU/Load/Kernel:avg
Scale: 1000
unit: %
value: 125
------------------

here the virtual machine has one virtual cpu
please correct me if i am wrong, the CPU/Load/User:avg is 6.6 % of virtual CPU and CPU/Load/Kernel:avg is 12.5% of virtual CPU, therefore the total the average CPU usage in the monitoring period is 12.5+6.6= 19.1 % of the virtual CPU
is explanation for these values correct?
thanks

[noteirak]

here the virtual machine has one virtual cpu
please correct me if i am wrong, the CPU/Load/User:avg is 6.6 % and CPU/Load/Kernel:avg is 12.5%

I think the values are actually 0.066% and 0.125%
Scale is 1000, max value is 100000, so 100000 would be 100% while the scale would give you where to put the decimal delimiter

If you want from the guest, you need Guest/CPU/Load/<type>

[noteirak]

I've edited my previous reply, make sure to double check it

[Ghetas]

here the virtual machine has one virtual cpu
please correct me if i am wrong, the CPU/Load/User:avg is 6.6 % and CPU/Load/Kernel:avg is 12.5%

I think the values are actually 0.066% and 0.125%
Scale is 1000, max value is 100000, so 100000 would be 100% while the scale would give you where to put the decimal delimiter

If you want from the guest, you need Guest/CPU/Load/<type>

i want to get the virtual CPU usage of Virtual machine now i update the metric as follows

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oCollector.setupMetrics(Arrays.asList(new String[]{"Guest/CPU/Load/User:avg"}),

and

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        List<Integer> values = oCollector.queryMetricsData(Arrays.asList(new String[]{"Guest/CPU/Load/User:avg"}),
                Arrays.asList(new IUnknown[]{machine}),
                names, objects, units, scales,
                sequenceNumbers, indices, lengths);

and i use the following to get the metrics as before

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        for (int i=0; i < names.value.size(); i++){
        		
        		System.out.println("Metric Name: "+names.value.get(i));
        		System.out.println("Scale: "+scales.value.get(i));
        		System.out.println("unit: "+units.value.get(i));
        		scale=scales.value.get(i);
                for (int j = 0; j < lengths.value.get(i); j++)
                {
                    long val= values.get(indices.value.get(i).intValue() + j).longValue();
                    Long val2=val;
                    double val3=val2.doubleValue()/scale;
                    System.out.println(val3);
                }
        }

but it does not give me any values

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Metric Name: Guest/CPU/Load/User:avg
Scale: 1000
unit: %
------------------

[noteirak]

Do you have the guest additions installed in the VM? Last I rememeber, guest metrics don't work if they are not installed.

[Ghetas]

Do you have the guest additions installed in the VM? Last I rememeber, guest metrics don't work if they are not installed.

no i don't, i will install and try again
thanks so much noteirak

[Ghetas]

Do you have the guest additions installed in the VM? Last I rememeber, guest metrics don't work if they are not installed.

Thanks noteirak i installed Guest Additions and now it works with me very well

thanks

[noteirak]

Glad this is solved then happy coding!

[Ghetas]

Glad this is solved then happy coding!

hi noteirak
my code is running well but i noticed one problem
i setup the metric using

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	public void setup(long Period, long Count){
		 oCollector = vbox.getPerformanceCollector();
         oCollector.setupMetrics(Arrays.asList(new String[]{"Guest/CPU/Load/Kernel:avg,Guest/CPU/Load/User:avg,Guest/CPU/Load/Idle:avg"}),
                 new ArrayList<IUnknown>(),
                 Period, Count);
	}

and collect performance using

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        List<Integer> values = oCollector.queryMetricsData(Arrays.asList(new String[]{"Guest/CPU/Load/Kernel:avg,Guest/CPU/Load/User:avg,Guest/CPU/Load/Idle:avg"}),
                Arrays.asList(new IUnknown[]{machine}),
                names, objects, units, scales,
                sequenceNumbers, indices, lengths);

the code is running well and gives me correct values but if i restart my VM and try to run my code again to collect performance values it returns all values zero
but if i change the setup to

Code: Select all

	public void setup(long Period, long Count){
		 oCollector = vbox.getPerformanceCollector();
         oCollector.setupMetrics(Arrays.asList(new String[]{"*"}),
                 new ArrayList<IUnknown>(),
                 Period, Count);
	}

and try to run the code it gives me values that are correct and non zeros

is there any explanation and solution to this ?

appreciate your help

[noteirak]

If by restart you mean poweroff and then poweron, this is normal. Performance metrics collector are bound to the running process of the VM and therefore lost when you restart it.
You'll need to re-add a performance collector when the VM restart. This is explained in the description of IPerformanceCollector.

If you want to do it the right way, you would need to setup an event listener on IVirtualBox object that would add the performance monitor again.
If you go in the Samples topic, you'll find a specific example for events that show the particular event you're looking for. While it's for 4.3.x, just adjust the imports for 5.0.x and it should work out of the box.

[Ghetas]

If by restart you mean poweroff and then poweron, this is normal. Performance metrics collector are bound to the running process of the VM and therefore lost when you restart it.
You'll need to re-add a performance collector when the VM restart. This is explained in the description of IPerformanceCollector.

If you want to do it the right way, you would need to setup an event listener on IVirtualBox object that would add the performance monitor again.
If you go in the Samples topic, you'll find a specific example for events that show the particular event you're looking for. While it's for 4.3.x, just adjust the imports for 5.0.x and it should work out of the box.

let me check and understand how it works and come back a while

[Ghetas]

Hello noteirak
please this is the problem in details

if i call the oCollector.setupMetrics with the same type of performance metrics that i used before i turn off the vm then the following function

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public void CollectCpuUtilization(long time) throws InterruptedException{
        Holder<List<String>> names = new Holder<List<String>> ();
        Holder<List<IUnknown>> objects = new Holder<List<IUnknown>>() ;
        Holder<List<String>> units = new Holder<List<String>>();
        Holder<List<Long>> scales =  new Holder<List<Long>>();
        Holder<List<Long>> sequenceNumbers =  new Holder<List<Long>>();
        Holder<List<Long>> indices =  new Holder<List<Long>>();
        Holder<List<Long>> lengths =  new Holder<List<Long>>();
        oCollector = vbox.getPerformanceCollector();         

        List<Integer> values = oCollector.queryMetricsData(Arrays.asList(new String[]{"CPU/*:avg"}),
                Arrays.asList(new IUnknown[]{machine}),
                names, objects, units, scales,
                sequenceNumbers, indices, lengths);
        Cpuutilization=0;
        System.out.println();
        for (int i=0; i < names.value.size(); i++){
              scale=scales.value.get(i);
              System.out.println(names.value.get(i));
                for (int j = 0; j < lengths.value.get(i); j++)
                {
                    long val= values.get(indices.value.get(i).intValue() + j).longValue();
                    System.out.println(val);
                    Long val2=val;
                }
        }

        System.out.println("------------------");
        disconnect();
       
   }

it reruns all values zero

but if i change the performance metrics than i used before i turned off the VM it gives me correct values.

to solve this problem i tried to call the setup metrics every time i turned vm on and off but it still not working
i hope i could make it clear
appreciated your help thanks