NServiceBus Machine Latency Windows Performance Counter Sample

OriginatingMachineLatencyBehavior-v7.cs

using System;
using System.Collections.Concurrent;
using System.Diagnostics;
using System.Threading.Tasks;
using NServiceBus;
using NServiceBus.Pipeline;

class OriginatingMachineLatencyBehavior : Behavior<IIncomingPhysicalMessageContext>
{
    ConcurrentDictionary<string, (PerformanceCounter Counter, PerformanceCounter Base)> machineCounters = new ConcurrentDictionary<string, (PerformanceCounter,PerformanceCounter)>();
    const string Category = "NServiceBus Machine Latency Sample";
    const string LatencyDurationKey = "Latency Duration";
    const string LatencyDurationBaseKey = LatencyDurationKey + "Base";

    public OriginatingMachineLatencyBehavior()
    {
        if (PerformanceCounterCategory.Exists(Category))
        {
            return;
        }

        var counterCreationDataCollection = new CounterCreationDataCollection
        {
            new CounterCreationData(LatencyDurationKey, "Time between sending and fetching the message. Requires all system clocks to be synchronized!", PerformanceCounterType.AverageTimer32),
            new CounterCreationData(LatencyDurationBaseKey, string.Empty, PerformanceCounterType.AverageBase)
        };
        PerformanceCounterCategory.Create(Category, "Sample showing how to monitor the time between sending and fetching a message just before invoking the handlers (excluding processing time).", PerformanceCounterCategoryType.MultiInstance, counterCreationDataCollection);
    }

    public override Task Invoke(IIncomingPhysicalMessageContext context, Func<Task> next)
    {
        var headers = context.MessageHeaders;
        var originatingMachine = headers[Headers.OriginatingMachine];
        var timeSent = DateTimeExtensions.ToUtcDateTime(headers[Headers.TimeSent]);

        var counter = machineCounters.GetOrAdd(originatingMachine, k => (new PerformanceCounter(Category, LatencyDurationKey, originatingMachine, false),new PerformanceCounter(Category, LatencyDurationBaseKey, originatingMachine, false)));

        var duration = DateTime.UtcNow - timeSent;

        var performanceCounterTicks = duration.Ticks * Stopwatch.Frequency / TimeSpan.TicksPerSecond;

        counter.Counter.IncrementBy(duration.Ticks);
        counter.Base.Increment();

        return next();
    }
}