Provide MeterProvider to replace MeterFactory to be in sync with spec. (

#919) * Provide MeterProvider to replace MeterFactory to be in sync with spec. * move OpenTelemetrymetrics to metrics folder * Update examples/Console/TestPrometheusExporter.cs Co-authored-by: Reiley Yang <[email protected]> * Sdk.CreateTracerProvider CreateMeterProvider * move Sdk to root * makr Sdk static Co-authored-by: Reiley Yang <[email protected]>
open-telemetry · Jul 24, 2020 · 920b0ed · 920b0ed
1 parent e416063
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Showing 47 changed files with 316 additions and 169 deletions.
diff --git a/docs/getting-started.md b/docs/getting-started.md
@@ -29,6 +29,7 @@ Update the `Program.cs` file with the following code:
 
 ```csharp
 using System.Diagnostics;
+using OpenTelemetry;
 using OpenTelemetry.Trace;
 
 class Program
@@ -38,7 +39,7 @@ class Program
 
     static void Main()
     {
-        using var otel = OpenTelemetrySdk.CreateTracerProvider(b => b
+        using var otel = Sdk.CreateTracerProvider(b => b
             .AddActivitySource("MyCompany.MyProduct.MyLibrary")
             .UseConsoleExporter());
 
@@ -74,7 +75,7 @@ Tracer](https://github.com/open-telemetry/opentelemetry-specification/blob/maste
 The activitysource instance is used to start an `Activity` which represent
 [OpenTelemetry
 Span](https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/trace/api.md#span).
-`OpenTelemetrySdk.CreateTracerProvider` sets up the OpenTelemetry Sdk, and
+`Sdk.CreateTracerProvider` sets up the OpenTelemetry Sdk, and
 configures it to subscribe to the activities from the source
 `MyCompany.MyProduct.MyLibrary`, and export it to `ConsoleExporter`, which
 simply displays it on the console.
diff --git a/examples/AspNet/Global.asax.cs b/examples/AspNet/Global.asax.cs
@@ -3,6 +3,7 @@
 using System.Web.Http;
 using System.Web.Mvc;
 using System.Web.Routing;
+using OpenTelemetry;
 using OpenTelemetry.Trace;
 
 namespace Examples.AspNet
@@ -13,7 +14,7 @@ public class WebApiApplication : HttpApplication
 
         protected void Application_Start()
         {
-            this.openTelemetry = OpenTelemetrySdk.CreateTracerProvider(
+            this.openTelemetry = Sdk.CreateTracerProvider(
                  (builder) => builder
                  .AddHttpInstrumentation()
                  .AddAspNetInstrumentation()

diff --git a/examples/Console/TestConsoleExporter.cs b/examples/Console/TestConsoleExporter.cs
@@ -18,6 +18,7 @@
 using System.Diagnostics;
 using System.Threading;
 using System.Threading.Tasks;
+using OpenTelemetry;
 using OpenTelemetry.Resources;
 using OpenTelemetry.Trace;
 
@@ -29,7 +30,7 @@ internal static object Run(ConsoleOptions options)
         {
             // Enable TracerProvider for the source "MyCompany.MyProduct.MyWebServer"
             // and use a single pipeline with a custom MyProcessor, and Console exporter.
-            using var tracerProvider = OpenTelemetrySdk.CreateTracerProvider(
+            using var tracerProvider = Sdk.CreateTracerProvider(
                 (builder) => builder.AddActivitySource("MyCompany.MyProduct.MyWebServer")
                     .SetResource(Resources.CreateServiceResource("MyServiceName"))
                     .UseConsoleExporter(opt => opt.DisplayAsJson = options.DisplayAsJson,

diff --git a/examples/Console/TestHttpClient.cs b/examples/Console/TestHttpClient.cs
@@ -15,6 +15,7 @@
 // </copyright>
 using System.Diagnostics;
 using System.Net.Http;
+using OpenTelemetry;
 using OpenTelemetry.Resources;
 using OpenTelemetry.Trace;
 
@@ -26,7 +27,7 @@ internal static object Run()
         {
             System.Console.WriteLine("Hello World!");
 
-            using var openTelemetry = OpenTelemetrySdk.CreateTracerProvider(
+            using var openTelemetry = Sdk.CreateTracerProvider(
                 (builder) => builder.AddHttpClientInstrumentation()
                 .SetResource(Resources.CreateServiceResource("http-service-example"))
                 .AddActivitySource("http-client-test")

diff --git a/examples/Console/TestJaegerExporter.cs b/examples/Console/TestJaegerExporter.cs
@@ -15,6 +15,7 @@
 // </copyright>
 using System;
 
+using OpenTelemetry;
 using OpenTelemetry.Trace;
 
 namespace Examples.Console
@@ -30,7 +31,7 @@ internal static object RunWithActivity(string host, int port)
         {
             // Enable OpenTelemetry for the sources "Samples.SampleServer" and "Samples.SampleClient"
             // and use the Jaeger exporter.
-            using var openTelemetry = OpenTelemetrySdk.CreateTracerProvider(
+            using var openTelemetry = Sdk.CreateTracerProvider(
                 builder => builder
                     .AddActivitySource("Samples.SampleServer")
                     .AddActivitySource("Samples.SampleClient")

diff --git a/examples/Console/TestOTelShimWithConsoleExporter.cs b/examples/Console/TestOTelShimWithConsoleExporter.cs
@@ -14,6 +14,7 @@
 // limitations under the License.
 // </copyright>
 
+using OpenTelemetry;
 using OpenTelemetry.Resources;
 using OpenTelemetry.Trace;
 
@@ -25,7 +26,7 @@ internal static object Run(OpenTelemetryShimOptions options)
         {
             // Enable OpenTelemetry for the source "MyCompany.MyProduct.MyWebServer"
             // and use a single pipeline with a custom MyProcessor, and Console exporter.
-            using var tracerProvider = OpenTelemetrySdk.CreateTracerProvider(
+            using var tracerProvider = Sdk.CreateTracerProvider(
                 (builder) => builder.AddActivitySource("MyCompany.MyProduct.MyWebServer")
                     .SetResource(Resources.CreateServiceResource("MyServiceName"))
                     .UseConsoleExporter(opt => opt.DisplayAsJson = options.DisplayAsJson));

diff --git a/examples/Console/TestOpenTracingWithConsoleExporter.cs b/examples/Console/TestOpenTracingWithConsoleExporter.cs
@@ -14,6 +14,7 @@
 // limitations under the License.
 // </copyright>
 
+using OpenTelemetry;
 using OpenTelemetry.Context.Propagation;
 using OpenTelemetry.Resources;
 using OpenTelemetry.Shims.OpenTracing;
@@ -28,7 +29,7 @@ internal static object Run(OpenTracingShimOptions options)
         {
             // Enable OpenTelemetry for the source "MyCompany.MyProduct.MyWebServer"
             // and use Console exporter.
-            using var openTelemetry = OpenTelemetrySdk.CreateTracerProvider(
+            using var openTelemetry = Sdk.CreateTracerProvider(
                 (builder) => builder.AddActivitySource("MyCompany.MyProduct.MyWebServer")
                     .SetResource(Resources.CreateServiceResource("MyServiceName"))
                     .UseConsoleExporter(opt => opt.DisplayAsJson = options.DisplayAsJson));

diff --git a/examples/Console/TestOtlpExporter.cs b/examples/Console/TestOtlpExporter.cs
@@ -14,6 +14,7 @@
 // limitations under the License.
 // </copyright>
 
+using OpenTelemetry;
 using OpenTelemetry.Trace;
 
 namespace Examples.Console
@@ -29,7 +30,7 @@ private static object RunWithActivitySource(string endpoint)
         {
             // Enable OpenTelemetry for the sources "Samples.SampleServer" and "Samples.SampleClient"
             // and use OTLP exporter.
-            using var openTelemetry = OpenTelemetrySdk.CreateTracerProvider(
+            using var openTelemetry = Sdk.CreateTracerProvider(
                 builder => builder
                     .AddActivitySource("Samples.SampleServer")
                     .AddActivitySource("Samples.SampleClient")

diff --git a/examples/Console/TestPrometheusExporter.cs b/examples/Console/TestPrometheusExporter.cs
@@ -18,6 +18,7 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Threading.Tasks;
+using OpenTelemetry;
 using OpenTelemetry.Exporter.Prometheus;
 using OpenTelemetry.Metrics;
 using OpenTelemetry.Metrics.Export;
@@ -54,17 +55,22 @@ internal static async Task<object> RunAsync(int port, int pushIntervalInSecs, in
             // Create Processor (called Batcher in Metric spec, this is still not decided)
             var processor = new UngroupedBatcher();
 
-            // MeterFactory is from where one can obtain Meters.
-            // All meters from this factory will be configured with the common processor.
-            var meterFactory = MeterFactory.Create(mb =>
-                {
-                    mb.SetMetricProcessor(processor);
-                    mb.SetMetricExporter(promExporter);
-                    mb.SetMetricPushInterval(TimeSpan.FromSeconds(pushIntervalInSecs));
-                });
-
-            // Obtain a Meter. Libraries would pass their name as argument.
-            var meter = meterFactory.GetMeter("MyMeter");
+            // Application which decides to enable OpenTelemetry metrics
+            // would setup a MeterProvider and make it default.
+            // All meters from this factory will be configured with the common processing pipeline.
+            MeterProvider.SetDefault(Sdk.CreateMeterProvider(mb =>
+            {
+                mb.SetMetricProcessor(processor);
+                mb.SetMetricExporter(promExporter);
+                mb.SetMetricPushInterval(TimeSpan.FromSeconds(pushIntervalInSecs));
+            }));
+
+            // The following shows how libraries would obtain a MeterProvider.
+            // MeterProvider is the entry point, which provides Meter.
+            // If user did not set the Default MeterProvider (shown in earlier lines),
+            // all metric operations become no-ops.
+            var meterProvider = MeterProvider.Default;
+            var meter = meterProvider.GetMeter("MyMeter");
 
             // the rest is purely from Metrics API.
             var testCounter = meter.CreateInt64Counter("MyCounter");

diff --git a/examples/Console/TestRedis.cs b/examples/Console/TestRedis.cs
@@ -17,6 +17,7 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Threading;
+using OpenTelemetry;
 using OpenTelemetry.Trace;
 using StackExchange.Redis;
 
@@ -41,7 +42,7 @@ internal static object Run(string zipkinUri)
             var connection = ConnectionMultiplexer.Connect("localhost");
 
             // Configure exporter to export traces to Zipkin
-            using var openTelemetry = OpenTelemetrySdk.CreateTracerProvider(
+            using var openTelemetry = Sdk.CreateTracerProvider(
                 builder => builder
                     .UseZipkinExporter(o =>
                     {

diff --git a/examples/Console/TestZPagesExporter.cs b/examples/Console/TestZPagesExporter.cs
@@ -16,6 +16,7 @@
 
 using System.Diagnostics;
 using System.Threading;
+using OpenTelemetry;
 using OpenTelemetry.Exporter.ZPages;
 using OpenTelemetry.Trace;
 
@@ -33,7 +34,7 @@ internal static object Run()
             // Start the server
             httpServer.Start();
 
-            using var openTelemetry = OpenTelemetrySdk.CreateTracerProvider(
+            using var openTelemetry = Sdk.CreateTracerProvider(
                 builder => builder
                     .AddActivitySource("zpages-test")
                     .UseZPagesExporter(

diff --git a/examples/Console/TestZipkinExporter.cs b/examples/Console/TestZipkinExporter.cs
@@ -15,6 +15,7 @@
 // </copyright>
 
 using System;
+using OpenTelemetry;
 using OpenTelemetry.Trace;
 
 namespace Examples.Console
@@ -32,7 +33,7 @@ internal static object Run(string zipkinUri)
 
             // Enable OpenTelemetry for the sources "Samples.SampleServer" and "Samples.SampleClient"
             // and use the Zipkin exporter.
-            using var openTelemetry = OpenTelemetrySdk.CreateTracerProvider(
+            using var openTelemetry = Sdk.CreateTracerProvider(
                 builder => builder
                     .AddActivitySource("Samples.SampleServer")
                     .AddActivitySource("Samples.SampleClient")

diff --git a/src/OpenTelemetry.Api/Metrics/MeterProvider.cs b/src/OpenTelemetry.Api/Metrics/MeterProvider.cs
@@ -0,0 +1,98 @@
+// <copyright file="MeterProvider.cs" company="OpenTelemetry Authors">
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// </copyright>
+
+using System;
+
+namespace OpenTelemetry.Metrics
+{
+    /// <summary>
+    /// MeterProvider is the entry point of the OpenTelemetry Metrics API. It provides access to Meters.
+    /// </summary>
+    public class MeterProvider : IDisposable
+    {
+        private static ProxyMeter proxyMeter = new ProxyMeter();
+        private static bool isInitialized;
+        private static MeterProvider defaultProvider = new MeterProvider();
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="MeterProvider"/> class.
+        /// </summary>
+        protected MeterProvider()
+        {
+        }
+
+        /// <summary>
+        /// Gets the dafult instance of a <see cref="MeterProvider"/>.
+        /// </summary>
+        public static MeterProvider Default
+        {
+            get => defaultProvider;
+        }
+
+        /// <summary>
+        /// Sets the default instance of <see cref="MeterProvider"/>.
+        /// </summary>
+        /// <param name="meterProvider">Instance of <see cref="MeterProvider"/>.</param>
+        /// <remarks>
+        /// This method can only be called once. Calling it multiple times will throw an <see cref="System.InvalidOperationException"/>.
+        /// </remarks>
+        /// <exception cref="InvalidOperationException">Thrown when called multiple times.</exception>
+        public static void SetDefault(MeterProvider meterProvider)
+        {
+            if (isInitialized)
+            {
+                throw new InvalidOperationException("Default factory is already set");
+            }
+
+            defaultProvider = meterProvider ?? throw new ArgumentNullException(nameof(meterProvider));
+
+            // some libraries might have already used and cached ProxyMeter.
+            // let's update it to real one and forward all calls.
+
+            // TODO:
+            // resource assignment is not possible for libraries that cache meter before SDK is initialized.
+            // SDK (Meter) must be at least partially initialized before any collection starts to capture resources.
+            // we might be able to work this around in future.
+            proxyMeter.UpdateMeter(defaultProvider.GetMeter(null));
+
+            isInitialized = true;
+        }
+
+        /// <inheritdoc/>
+        public virtual void Dispose()
+        {
+        }
+
+        /// <summary>
+        /// Returns a Meter for a given name and version.
+        /// </summary>
+        /// <param name="name">Name of the instrumentation library.</param>
+        /// <param name="version">Version of the instrumentation library (optional).</param>
+        /// <returns>Meter for the given name and version information.</returns>
+        public virtual Meter GetMeter(string name, string version = null)
+        {
+            return isInitialized ? defaultProvider.GetMeter(name, version) : proxyMeter;
+        }
+
+        // for tests
+        internal void Reset()
+        {
+            proxyMeter = new ProxyMeter();
+            isInitialized = false;
+            defaultProvider = new MeterProvider();
+        }
+    }
+}
diff --git a/src/OpenTelemetry.Extensions.Hosting/OpenTelemetryServicesExtensions.cs b/src/OpenTelemetry.Extensions.Hosting/OpenTelemetryServicesExtensions.cs
@@ -17,6 +17,7 @@
 using System;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Hosting;
+using OpenTelemetry;
 using OpenTelemetry.Extensions.Hosting.Implementation;
 using OpenTelemetry.Trace;
 
@@ -46,7 +47,7 @@ public static IServiceCollection AddOpenTelemetry(this IServiceCollection servic
         /// <returns>The <see cref="IServiceCollection"/> so that additional calls can be chained.</returns>
         public static IServiceCollection AddOpenTelemetry(this IServiceCollection services, Action<TracerProviderBuilder> configure)
         {
-            services.AddOpenTelemetry(() => OpenTelemetrySdk.CreateTracerProvider(configure));
+            services.AddOpenTelemetry(() => Sdk.CreateTracerProvider(configure));
             return services;
         }
 
@@ -58,7 +59,7 @@ public static IServiceCollection AddOpenTelemetry(this IServiceCollection servic
         /// <returns>The <see cref="IServiceCollection"/> so that additional calls can be chained.</returns>
         public static IServiceCollection AddOpenTelemetry(this IServiceCollection services, Action<IServiceProvider, TracerProviderBuilder> configure)
         {
-            services.AddOpenTelemetry(s => OpenTelemetrySdk.CreateTracerProvider(builder => configure(s, builder)));
+            services.AddOpenTelemetry(s => Sdk.CreateTracerProvider(builder => configure(s, builder)));
             return services;
         }
 

diff --git a/src/OpenTelemetry.Instrumentation.StackExchangeRedis/README.md b/src/OpenTelemetry.Instrumentation.StackExchangeRedis/README.md
@@ -19,7 +19,7 @@ dotnet add package OpenTelemetry.Instrumentation.StackExchangeRedis
 using var connection = ConnectionMultiplexer.Connect("localhost:6379");
 
 // Pass the connection to AddRedisInstrumentation.
-using var openTelemetry = OpenTelemetrySdk.CreateTracerProvider(b => b
+using var openTelemetry = Sdk.CreateTracerProvider(b => b
     .AddRedisInstrumentation(connection)
     .UseZipkinExporter()
     .SetResource(Resources.CreateServiceResource("my-service"));

diff --git a/src/OpenTelemetry/Metrics/Export/PushMetricController.cs b/src/OpenTelemetry/Metrics/Export/PushMetricController.cs
@@ -20,7 +20,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using OpenTelemetry.Internal;
-using static OpenTelemetry.Metrics.MeterFactory;
+using static OpenTelemetry.Metrics.MeterProviderSdk;
 
 namespace OpenTelemetry.Metrics.Export
 {