Performance Monitor Grid

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Introduction

The Performance Monitor Grid (PMG) displays performance counters of machines on a network in a DataGrid format. Each row in the DataGrid indicates the CPU%, Available Memory (in Megabytes) and Disk % for a particular host. A user can monitor up to 5 machines on the network at a time.

When closed, the application window remains in the systray and would "alert" the user if the performance counters on any host exceeds a certain threshold.

Background

Well, cutting to the chase, I am currently learning C# and writing some code along the way sounded good to me. If any piece of code in this app becomes useful to you any day, I would be really happy!

Using the code

The code uses .NET's WMI PerfRawData classes of the System.Management namespace. Figuring out how to make sense out of the "raw data" returned by these classes was a pain and I had to spend quite sometime in MSDN and Google for that!

The PerfRow class is the core class of the application. A separate instance of this class is created for each row in the DataGrid. The code below shows the connect method of the PerfRow class to connect to a host.

public int Connect()
{
    if (Dns.GetHostName() == strHostName)
    {
        mgmtScope = new 
          ManagementScope("\\\\" + strHostName+ "\\root\\cimv2");
    }
    else
    {
        options          = new ConnectionOptions();
        options.Username = strUserName;
        options.Password = strPassword;

        // scope object for remote machine
        mgmtScope = new 
          ManagementScope("\\\\" + strHostName + "\\root\\cimv2",options);
        
    }

    // connect to machine to monitor. Return 0 if not able to connect
    try
    {
        mgmtScope.Connect();
    }
    catch(System.UnauthorizedAccessException)
    {
        return 0;
    }

    // CPU%
    mPath_CPU                = new ManagementPath();
    mPath_CPU.RelativePath   = "Win32_PerfRawData_PerfOS_Processor.Name='0'";
    mObject_CPU  = new ManagementObject(mgmtScope,mPath_CPU,null);

    // Memory Available (in MBytes)
    mPath_Mem                = new ManagementPath();
    mPath_Mem.RelativePath   = "Win32_PerfRawData_PerfOS_Memory";
    mc  = new ManagementClass(mgmtScope,mPath_Mem,null);

    // Disk %            
    mPath_Disk               = new ManagementPath();
    mPath_Disk.RelativePath  = 
      "Win32_PerfRawData_PerfDisk_PhysicalDisk.Name='_total'";
    mObject_Disk = new ManagementObject(mgmtScope,mPath_Disk,null);

    return 1;
}

The PerfRow class contains the GetCPU(), GetDisk() and the GetMemory() methods to return the respective performance counters.

public string GetCPU()
{
    decimal PercentProcessorTime=0;
    mObject_CPU.Get();

    ulong  u_newCPU   = 
      (ulong)mObject_CPU.Properties["PercentProcessorTime"].Value;
    ulong u_newNano   = 
      (ulong)mObject_CPU.Properties["TimeStamp_Sys100NS"].Value;
    decimal d_newCPU  = Convert.ToDecimal(u_newCPU);
    decimal d_newNano = Convert.ToDecimal(u_newNano);
    decimal d_oldCPU  = Convert.ToDecimal(u_oldCPU);
    decimal d_oldNano = Convert.ToDecimal(u_oldNano);

    // Thanks to MSDN for giving me this formula !
    PercentProcessorTime = 
      (1 - ((d_newCPU-d_oldCPU)/(d_newNano - d_oldNano)))*100m;

    // Save the values for the next run
    u_oldCPU          = u_newCPU;
    u_oldNano         = u_newNano;
            
    return PercentProcessorTime.ToString("N",nfi);;
}

Points of interest

Need to add a lot of tweaks to the code. I have just about ignored cleaning up memory. Also would like to introduce an e-mailing feature in the alerts.

History

First cut on November 4th 2003