指标工具

using System.Diagnostics.Metrics;

// Create a meter
var meter = new Meter("MyCompany.MyProduct", "1.0.0");

// Create a counter
var requestCounter = meter.CreateCounter<long>("request_counter", "requests", "Counts the number of requests");

// Increment by 1
requestCounter.Add(1);

// Increment with attributes
requestCounter.Add(1, new("endpoint", "/api/users"), new("method", "GET"));

// Create an up-down counter
var activeConnectionsCounter = meter.CreateUpDownCounter<int>("active_connections", "connections", "Number of active connections");

// Increment by 1
activeConnectionsCounter.Add(1);

// Decrement by 1
activeConnectionsCounter.Add(-1);

// With attributes
activeConnectionsCounter.Add(1, new("pool", "worker"), new("region", "west"));

// Create a histogram
var requestDurationHistogram = meter.CreateHistogram<double>("request_duration", "ms", "Request duration in milliseconds");

// Record a duration
requestDurationHistogram.Record(213.5);

// With attributes
requestDurationHistogram.Record(42.3, new("endpoint", "/api/users"), new("method", "GET"));

// Create an observable counter
meter.CreateObservableCounter("processed_items_total", () =>
{
    // Return the current count from some internal state
    return new Measurement<long>(GetCurrentProcessedCount(), new("queue", "default"));
}, "items", "Total number of processed items");

// Create an observable up-down counter
meter.CreateObservableUpDownCounter("active_tasks", () =>
{
    // Return current values from internal state
    return new[]
    {
        new Measurement<int>(GetHighPriorityTaskCount(), new("priority", "high")),
        new Measurement<int>(GetLowPriorityTaskCount(), new("priority", "low"))
    };
}, "tasks", "Current number of active tasks");

// Create an observable gauge
meter.CreateObservableGauge("cpu_usage", () =>
{
    // Get current CPU usage percentage
    return new Measurement<double>(GetCurrentCpuUsage());
}, "%", "Current CPU usage percentage");

// Register a single callback for multiple observable instruments
var observableCounter = meter.CreateObservableCounter<long>("my_observable_counter", "items");
var observableGauge = meter.CreateObservableGauge<double>("my_observable_gauge", "%");

meter.RegisterObservableCallback(observableInstruments =>
{
    // Record a value for the counter
    observableInstruments.Observe(observableCounter, 42, new("type", "product_a"));

    // Record a value for the gauge
    observableInstruments.Observe(observableGauge, 12.3, new("resource", "cpu"));
}, observableCounter, observableGauge);

// Specify unit and description
var requestSizeHistogram = meter.CreateHistogram<long>(
    name: "http.request.size",
    unit: "By",  // bytes
    description: "Size of HTTP request in bytes"
);