prometheus-net

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using System.Diagnostics.Metrics;
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/// <summary>
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/// Sample custom metrics exported via the .NET Meters API.
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/// </summary>
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public static class CustomDotNetMeters
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{
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    public static void PublishSampleData()
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    {
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        // The meter object is the "container" for all the .NET metrics we will be publishing.
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        var meter1 = new Meter("Foobar.Wingwang.Dingdong", "vNext");
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        // Example metric: a simple counter.
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        var counter1 = meter1.CreateCounter<int>("wings-wanged", "wings", "Counts the number of wings that have been wanged.");
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        double nameCount = 1_000_000_000;
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        double HowManyNamesAreThereInTheWorld() => nameCount++;
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        var counter2 = meter1.CreateObservableCounter<double>("all-names", HowManyNamesAreThereInTheWorld, "names", "Count of how many unique names exist in the world up to this point");
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        // Example metric: an observable gauge.
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        IEnumerable<Measurement<double>> ObserveGrossNestsAll()
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        {
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            foreach (var neepitKeepit in Enumerable.Range(1, 10))
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                yield return new Measurement<double>(Random.Shared.Next(800), new KeyValuePair<string, object?>("beek-beek", "yes"), new KeyValuePair<string, object?>("neepit-keepit", Random.Shared.Next(neepitKeepit)));
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        }
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        var observableGauge1 = meter1.CreateObservableGauge<double>("gross-nests", ObserveGrossNestsAll, "nests (gross)", "Measures the amount of nests nested (gross).");
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        // Example metric: a histogram.
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        var histogram1 = meter1.CreateHistogram<byte>("bytes-considered", "bytes", "Informs about all the bytes considered.");
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        // .NET 7: Example metric: an up/down counter.
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        var upDown1 = meter1.CreateUpDownCounter<int>("water-level", "brick-heights", "Current water level in the tank (measured in visible bricks from the midpoint).");
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        // Example metric: an observable up/down counter.
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        int sandLevel = 0;
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        int MeasureSandLevel()
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        {
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            sandLevel += Random.Shared.Next(-1, 2);
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            return sandLevel;
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        }
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        var upDown2 = meter1.CreateObservableUpDownCounter<int>("sand-level", MeasureSandLevel, "chainlinks", "Current sand level in the tank (measured in visible chain links from the midpoint).");
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        // Example high cardinality metric: bytes sent per connection.
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        var highCardinalityCounter1 = meter1.CreateCounter<long>("bytes-sent", "bytes", "Bytes sent per connection.");
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        var activeConnections = new List<Guid>();
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        // Start with 10 active connections.
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        foreach (var _ in Enumerable.Range(0, 10))
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            activeConnections.Add(Guid.NewGuid());
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        // Dummy data generator.
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        _ = Task.Run(async delegate
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        {
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            while (true)
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            {
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                if (Random.Shared.Next(10) == 0)
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                    counter1.Add(1, new KeyValuePair<string, object?>("wing-type", "FlexxWing MaxxFling 3000"));
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                if (Random.Shared.Next(10) == 0)
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                    counter1.Add(1, new KeyValuePair<string, object?>("wing-type", "SlaxxWing 1.0"), new KeyValuePair<string, object?>("wing-version", "beta"));
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                // is-faulted here conflicts with the static label of the same name and gets overwritten by the static label.
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                histogram1.Record((byte)(Random.Shared.Next(256)), new KeyValuePair<string, object?>("is-faulted", true), new KeyValuePair<string, object?>("canbus_ver", "1.0"));
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                // .NET 7
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                upDown1.Add(Random.Shared.Next(-1, 2));
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                // Add some bytes for every active connection.
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                foreach (var connection in activeConnections)
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                    highCardinalityCounter1.Add(Random.Shared.Next(10_000_000), new KeyValuePair<string, object?>("connection-id", connection));
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                // Maybe some connection went away, maybe some was added.
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                // Timeseries that stop receiving updates will disappear from prometheus-net output after a short delay (up to 10 minutes by default).
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                if (Random.Shared.Next(100) == 0)
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                {
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                    activeConnections.RemoveAt(Random.Shared.Next(activeConnections.Count));
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                    activeConnections.Add(Guid.NewGuid());
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                }
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                await Task.Delay(100);
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            }
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        });
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    }
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}
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