Get cluster performance history

Applies to: Azure Stack HCI, versions 22H2; Windows Server 2022, Windows Server 2019

The Health Service reduces the work required to get live performance and capacity information from your Storage Spaces Direct cluster. One cmdlet provides a curated list of essential metrics, which are collected efficiently and aggregated dynamically across nodes, with built-in logic to detect cluster membership. All values are real-time and point-in-time only.

Usage in PowerShell

Use the following cmdlet to get metrics for the entire Storage Spaces Direct cluster:

Get-ClusterPerformanceHistory

You can also get metrics for one specific volume or server:

Get-Volume -FileSystemLabel <Label> | Get-ClusterPerformanceHistory

Get-StorageNode -Name <Name> | Get-ClusterPerformanceHistory

Usage in .NET and C#

This sections shows how to connect to the Health Service, use discover objects, and implement an Observer to begin streaming metrics.

Connect

In order to query the Health Service, you establish a CimSession with the cluster. To do so, you need some things that are only available in full Microsoft .NET, meaning you cannot readily do this directly from a web or mobile app. The code samples in this section use C#, the most straightforward choice for this data access layer.

using System.Security;
using Microsoft.Management.Infrastructure;

public CimSession Connect(string Domain = "...", string Computer = "...", string Username = "...", string Password = "...")
{
    SecureString PasswordSecureString = new SecureString();
    foreach (char c in Password)
    {
        PasswordSecureString.AppendChar(c);
    }

    CimCredential Credentials = new CimCredential(
        PasswordAuthenticationMechanism.Default, Domain, Username, PasswordSecureString);
    WSManSessionOptions SessionOptions = new WSManSessionOptions();
    SessionOptions.AddDestinationCredentials(Credentials);
    Session = CimSession.Create(Computer, SessionOptions);
    return Session;
}

The provided username should be a local administrator of the target computer.

We recommend constructing the Password SecureString directly from user input in real-time, so that the password is never stored in memory in cleartext. This helps mitigate a variety of security concerns. But in practice, constructing it as above is common for prototyping purposes.

Discover objects

With the CimSession established, you can query Windows Management Instrumentation (WMI) on the cluster.

Before you can get faults or metrics, you need to get instances of several relevant objects. First, get the MSFT_StorageSubSystem that represents Storage Spaces Direct on the cluster. Using that, you can get every MSFT_StorageNode in the cluster, and every MSFT_Volume of the data volumes. Finally, you need to get the MSCluster_ClusterHealthService, the Health Service itself.

CimInstance Cluster;
List<CimInstance> Nodes;
List<CimInstance> Volumes;
CimInstance HealthService;

public void DiscoverObjects(CimSession Session)
{
    // Get MSFT_StorageSubSystem for Storage Spaces Direct
    Cluster = Session.QueryInstances(@"root\microsoft\windows\storage", "WQL", "SELECT * FROM MSFT_StorageSubSystem")
        .First(Instance => (Instance.CimInstanceProperties["FriendlyName"].Value.ToString()).Contains("Cluster"));

    // Get MSFT_StorageNode for each cluster node
    Nodes = Session.EnumerateAssociatedInstances(Cluster.CimSystemProperties.Namespace,
        Cluster, "MSFT_StorageSubSystemToStorageNode", null, "StorageSubSystem", "StorageNode").ToList();

    // Get MSFT_Volumes for each data volume
    Volumes = Session.EnumerateAssociatedInstances(Cluster.CimSystemProperties.Namespace,
        Cluster, "MSFT_StorageSubSystemToVolume", null, "StorageSubSystem", "Volume").ToList();

    // Get MSCluster_ClusterHealthService itself
    HealthService = session.QueryInstances(@"root\MSCluster", "WQL", "SELECT * FROM MSCluster_ClusterHealthService").First();
}

These are the same objects you get in PowerShell using cmdlets like Get-StorageSubSystem, Get-StorageNode, and Get-Volume.

You can access all the same properties, documented at Storage Management API Classes.

using System.Diagnostics;

foreach (CimInstance Node in Nodes)
{
    // For illustration, write each node's Name to the console. You could also write State (up/down), or anything else!
    Debug.WriteLine("Discovered Node " + Node.CimInstanceProperties["Name"].Value.ToString());
}

Invoke GetMetric to begin streaming samples of an expert-curated list of essential metrics based on provided metric names from MetricName parameter, which are collected efficiently and aggregated dynamically across nodes, with built-in logic to detect cluster membership. Samples arrive based on the provided timeframe from the StreamName parameter.

For the complete list of available metrics, see Performance history for Storage Spaces Direct.

IObserver.OnNext()

This sample code uses the Observer Design Pattern to implement an Observer whose OnNext() method is invoked when each new sample of metrics arrives. Its OnCompleted() method is called if/when streaming ends. For example, you might use it to reinitiate streaming, so that it continues indefinitely.

class MetricsObserver<T> : IObserver<T>
{
    public void OnNext(T Result)
    {
        // Cast
        CimMethodStreamedResult StreamedResult = Result as CimMethodStreamedResult;

        if (StreamedResult != null)
        {
            CimInstance Metric = (CimInstance)StreamedResult.ItemValue;
            Console.WriteLine("MetricName: " + Metric.CimInstanceProperties["MetricId"].Value);
            IEnumerable<CimInstance> Records = (IEnumerable<CimInstance>)Metric.CimInstanceProperties["Records"].Value;

            foreach (CimInstance Record in Records)
            {
                // Each Record has "TimeStamp" and "Value. For Illustration, just print the metric"
                Console.WriteLine(record.CimInstanceProperties["TimeStamp"] + ": " + record.CimInstanceProperties["Value"]);

            }

            // TODO: Whatever you want!
        }
    }
    public void OnError(Exception e)
    {
        // Handle Exceptions
    }
    public void OnCompleted()
    {
        // Reinvoke BeginStreamingMetrics(), defined in the next section
    }
}

Begin streaming

With the Observer defined, you can begin streaming.

Specify the target CimInstance to which you want the metrics scoped. It can be the cluster, any node, or any volume.

The count parameter is the number of samples before streaming ends.

CimInstance Target = Cluster; // From among the objects discovered in DiscoverObjects()

public void BeginStreamingMetrics(CimSession Session, CimInstance HealthService, CimInstance Target)
{
    // Set Parameters
    CimMethodParametersCollection MetricsParams = new CimMethodParametersCollection();
    string[] metricNames = new string[] { "ClusterNode.Cpu.Usage,ClusterNode=RRN44-13-01", "ClusterNode.Cpu.Usage.Host,ClusterNode=RRN44-13-01" };
    MetricsParams.Add(CimMethodParameter.Create("MetricName", metricNames, CimType.StringArray, CimFlags.In));
    MetricsParams.Add(CimMethodParameter.Create("StreamName", "LastHour", CimType.String, CimFlags.In));

    // Enable WMI Streaming
    CimOperationOptions Options = new CimOperationOptions();
    Options.EnableMethodResultStreaming = true;
    // Invoke API
    CimAsyncMultipleResults<CimMethodResultBase> InvokeHandler;
    InvokeHandler = Session.InvokeMethodAsync(
        HealthService.CimSystemProperties.Namespace, HealthService, "GetMetric", MetricsParams, Options
        );
    // Subscribe the Observer
    MetricsObserver<CimMethodResultBase> Observer = new MetricsObserver<CimMethodResultBase>(this);
    IDisposable Disposeable = InvokeHandler.Subscribe(Observer);
}

These metrics can be visualized, stored in a database, or used in whatever way you see fit.

Additional references

• Performance history for Storage Spaces Direct