Aspire: enable Metrics for the FoundationDB componeent

- report the FdbClient metrics to the Aspire Host via OpenTelemetry
- add 'DisableMetrics' setting

Aspire.FoundationDB/FdbAspireComponentExtensions.cs

@@ -21,6 +21,7 @@ namespace Microsoft.Extensions.Hosting
 	using Microsoft.Extensions.Configuration;
 	using Microsoft.Extensions.DependencyInjection;
 	using Microsoft.Extensions.Diagnostics.HealthChecks;
+	using OpenTelemetry.Metrics;
 
 	/// <summary>Provides extension methods for adding FoundationDB to the local DI container.</summary>
 	[PublicAPI]
@@ -265,6 +266,23 @@ private static IHostApplicationBuilder AddFoundationDb(this IHostApplicationBuil
 					builder.Services.AddHealthChecks().Add(check);
 				}
 			}
+
+			if (!settings.DisableMetrics)
+			{
+				builder.Services.AddOpenTelemetry()
+					.WithMetrics((meterProviderBuilder) =>
+					{
+						meterProviderBuilder
+							.AddMeter("FdbClient")
+							.AddView("db.client.operation.duration",
+								new ExplicitBucketHistogramConfiguration
+								{
+									Boundaries = [0, 0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1, 2.5, 5, 7.5, 10],
+								})
+							;
+					});
+			}
+
 			return builder;
 		}
 
@@ -284,5 +302,4 @@ public Task<HealthCheckResult> CheckHealthAsync(HealthCheckContext context, Canc
 		}
 
 	}
-
 }

Aspire.FoundationDB/FdbClientSettings.cs

@@ -62,6 +62,10 @@ public sealed class FdbClientSettings
 		/// <remarks><para>Enabled by default.</para></remarks>
 		public bool DisableTracing { get; set; }
 
+		/// <summary>Gets or sets a boolean value that indicates whether the OpenTelemetry metrics are disabled or not.</summary>
+		/// <remarks><para>Enabled by default.</para></remarks>
+		public bool DisableMetrics { get; set; }
+
 	}
 
 }

Aspire.FoundationDB/FdbHealthCheck.cs

@@ -31,12 +31,14 @@ public FdbHealthCheck(FdbHealthCheckOptions options)
 
 		public FdbHealthCheckOptions Options { get; set; }
 
-		public async Task<HealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken cancellationToken = new CancellationToken())
+		public async Task<HealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken ct = default)
 		{
-			cancellationToken.ThrowIfCancellationRequested();
+			ct.ThrowIfCancellationRequested();
 			try
 			{
-				var rv = await this.Options.Provider.ReadAsync(tr => tr.GetReadVersionAsync(), cancellationToken);
+				//TODO: change this to get the "status json" ?
+
+				var rv = await this.Options.Provider.ReadAsync(tr => tr.GetReadVersionAsync(), ct);
 				return HealthCheckResult.Healthy(data: new Dictionary<string, object>()
 				{
 					["readVersion"] = rv,