Add Observability APIs to the SDK and add telemetry provider reference to AWSConfigs and ClientConfig

sdk/src/Core/AWSConfigs.cs

@@ -27,6 +27,7 @@
 using Amazon.Util.Internal;
 using System.Collections.Generic;
 using Amazon.Runtime;
+using Amazon.Runtime.Telemetry;
 
 namespace Amazon
 {
@@ -90,6 +91,7 @@ public static partial class AWSConfigs
         // for reading from awsconfigs.xml
         private static object _lock = new object();
         private static List<string> standardConfigs = new List<string>() { "region", "logging", "correctForClockSkew" };
+        private static TelemetryProvider _telemetryProvider = new DefaultTelemetryProvider();
 
 #pragma warning disable 414
         private static bool configPresent = true;
@@ -474,6 +476,19 @@ public static bool UseAlternateUserAgentHeader
             set { _rootConfig.UseAlternateUserAgentHeader = value; }
         }
 
+        /// <summary>
+        /// Gets or sets the global <see cref="TelemetryProvider"/> instance.
+        /// <para>
+        /// This global telemetry provider is used to collect and report telemetry data 
+        /// (such as traces and metrics) for all AWS SDK operations.
+        /// </para>
+        /// </summary>
+        public static TelemetryProvider TelemetryProvider
+        {
+            get { return _telemetryProvider; }
+            set { _telemetryProvider = value; }
+        }
+
         /// <summary>
         /// Configuration for the region endpoint section of AWS configuration.
         /// Changes may not take effect until a new client is constructed.

sdk/src/Core/Amazon.Runtime/ClientConfig.cs

@@ -29,6 +29,7 @@
 using System.ComponentModel.Design;
 using Amazon.Runtime.CredentialManagement;
 using Amazon.Runtime.Internal.Settings;
+using Amazon.Runtime.Telemetry;
 
 #if NETSTANDARD
 using System.Runtime.InteropServices;
@@ -93,6 +94,7 @@ public abstract partial class ClientConfig : IClientConfig
         private const long DefaultMinCompressionSizeBytes = 10240;
         private bool didProcessServiceURL = false;
         private IAWSTokenProvider _awsTokenProvider = new DefaultAWSTokenProviderChain();
+        private TelemetryProvider telemetryProvider = AWSConfigs.TelemetryProvider;
 
         private CredentialProfileStoreChain credentialProfileStoreChain;
 #if BCL
@@ -1239,5 +1241,20 @@ public TimeSpan? ReadWriteTimeout
         /// but can be changed to use custom user supplied EndpointProvider.
         /// </summary>
         public IEndpointProvider EndpointProvider { get; set; }
+
+        /// <summary>
+        /// Gets or sets the <see cref="TelemetryProvider"/> instance for this client configuration.
+        /// <para>
+        /// This telemetry provider is used to collect and report telemetry data 
+        /// (such as traces and metrics) for operations performed by this specific client.
+        /// If this property is not explicitly set, it will default to the global 
+        /// <see cref="AWSConfigs.TelemetryProvider"/>.
+        /// </para>
+        /// </summary>
+        public TelemetryProvider TelemetryProvider
+        {
+            get { return this.telemetryProvider; }
+            set { this.telemetryProvider = value; }
+        }
     }
 }

sdk/src/Core/Amazon.Runtime/IClientConfig.cs

@@ -18,6 +18,7 @@
 using Amazon.Runtime.Endpoints;
 using Amazon.Runtime.Internal.Auth;
 using Amazon.Util;
+using Amazon.Runtime.Telemetry;
 #if NETSTANDARD
 using System.Net.Http;
 #endif
@@ -369,6 +370,16 @@ public partial interface IClientConfig
         /// which doesn't allow to specify the User-Agent header.
         /// </summary>
         bool UseAlternateUserAgentHeader { get; }
+
+        /// <summary>
+        /// <para>
+        /// This telemetry provider is used to collect and report telemetry data 
+        /// (such as traces and metrics) for operations performed by this specific client.
+        /// If this property is not explicitly set, it will default to the global 
+        /// <see cref="AWSConfigs.TelemetryProvider"/>.
+        /// </para>
+        /// </summary>
+        TelemetryProvider TelemetryProvider { get; }
 #if BCL
         /// <summary>
         /// Gets the TCP keep-alive values to use for service requests. Enabling TCP keep-alive sends periodic TCP keep-alive probe packets, to prevent disconnection due to 

sdk/src/Core/Amazon.Runtime/Telemetry/Attributes.cs

@@ -0,0 +1,93 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ * 
+ *  http://aws.amazon.com/apache2.0
+ * 
+ * or in the "license" file accompanying this file. This file 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.
+ */
+
+using System.Collections.Generic;
+
+namespace Amazon.Runtime.Telemetry
+{
+    /// <summary>
+    /// Represents a collection of attributes used for telemetry purposes.
+    /// Attributes are key-value pairs where the key is a string and the value is an object.
+    /// These attributes provide additional information for spans and metrics in telemetry data.
+    /// </summary>
+    public class Attributes
+    {
+        private readonly Dictionary<string, object> _attributes;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Attributes"/> class.
+        /// </summary>
+        public Attributes()
+        {
+            _attributes = new Dictionary<string, object>();
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Attributes"/> class.
+        /// If duplicate keys are present in the provided collection, the value of the last occurrence of the key will be used.
+        /// </summary>
+        /// <param name="attributes">An optional initial set of attributes to populate the collection. 
+        /// If duplicate keys are found, the last value will override previous ones.</param>
+        public Attributes(IEnumerable<KeyValuePair<string, object>> attributes)
+        {
+            _attributes = new Dictionary<string, object>();
+
+            foreach (var kvp in attributes)
+            {
+                _attributes[kvp.Key] = kvp.Value;
+            }
+        }
+
+        /// <summary>
+        /// Sets the value for the given attribute key.
+        /// If the key already exists, the value is updated.
+        /// </summary>
+        /// <param name="key">The key of the attribute.</param>
+        /// <param name="value">The value of the attribute.</param>
+        public void Set(string key, object value)
+        {
+            _attributes[key] = value;
+        }
+
+        /// <summary>
+        /// Gets the value for the given attribute key.
+        /// </summary>
+        /// <param name="key">The attribute key.</param>
+        /// <returns>The attribute value, or null if the key does not exist.</returns>
+        public object Get(string key)
+        {
+            _attributes.TryGetValue(key, out var value);
+            return value;
+        }
+
+        /// <summary>
+        /// Removes the attribute with the specified key.
+        /// </summary>
+        /// <param name="key">The attribute key.</param>
+        /// <returns>True if the attribute was successfully removed; otherwise, false.</returns>
+        public bool Remove(string key)
+        {
+            return _attributes.Remove(key);
+        }
+
+        /// <summary>
+        /// Gets the collection of all the attributes.
+        /// </summary>
+        public IEnumerable<KeyValuePair<string, object>> AllAttributes
+        {
+            get { return _attributes; }
+        }
+    }
+}

sdk/src/Core/Amazon.Runtime/Telemetry/DefaultTelemetryProvider.cs

@@ -0,0 +1,73 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ * 
+ *  http://aws.amazon.com/apache2.0
+ * 
+ * or in the "license" file accompanying this file. This file 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.
+ */
+
+using Amazon.Runtime.Telemetry.Metrics;
+using Amazon.Runtime.Telemetry.Metrics.NoOp;
+using Amazon.Runtime.Telemetry.Tracing;
+using Amazon.Runtime.Telemetry.Tracing.NoOp;
+
+namespace Amazon.Runtime.Telemetry
+{
+    /// <summary>
+    /// Default implementation of <see cref="TelemetryProvider"/> that uses no-op providers by default.
+    /// </summary>
+    public class DefaultTelemetryProvider : TelemetryProvider
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="DefaultTelemetryProvider"/> class with no-op providers.
+        /// This setup prevents any telemetry actions from being performed unless explicitly registered using the
+        /// registration methods.
+        /// </summary>
+        public DefaultTelemetryProvider()
+        {
+            TracerProvider = new NoOpTracerProvider();
+            MeterProvider = new NoOpMeterProvider();
+        }
+
+        /// <summary>
+        /// Gets the <see cref="TracerProvider"/> used to create new tracers.
+        /// This property is initialized with a no-op implementation by default.
+        /// </summary>
+        public override TracerProvider TracerProvider { get; protected set; }
+
+        /// <summary>
+        /// Gets the <see cref="MeterProvider"/> used to create new metrics.
+        /// This property is initialized with a no-op implementation by default.
+        /// </summary>
+        public override MeterProvider MeterProvider { get; protected set; }
+
+        /// <summary>
+        /// Registers a new <see cref="TracerProvider"/>.
+        /// This method sets a custom tracer provider to replace the default no-op provider,
+        /// enabling the collection of tracing data.
+        /// </summary>
+        /// <param name="tracerProvider">The tracer provider to register.</param>
+        public override void RegisterTracerProvider(TracerProvider tracerProvider)
+        {
+            TracerProvider = tracerProvider;
+        }
+
+        /// <summary>
+        /// Registers a new <see cref="MeterProvider"/>.
+        /// This method sets a custom meter provider to replace the default no-op provider,
+        /// enabling the collection of metrics data.
+        /// </summary>
+        /// <param name="meterProvider">The meter provider to register.</param>
+        public override void RegisterMeterProvider(MeterProvider meterProvider)
+        {
+            MeterProvider = meterProvider;
+        }
+    }
+}

sdk/src/Core/Amazon.Runtime/Telemetry/Metrics/AsyncMeasurement.cs

@@ -0,0 +1,34 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ * 
+ *  http://aws.amazon.com/apache2.0
+ * 
+ * or in the "license" file accompanying this file. This file 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.
+ */
+
+namespace Amazon.Runtime.Telemetry.Metrics
+{
+    /// <summary>
+    /// Represents an async measurement.
+    /// An async measurement records values, such as periodically or based on events.
+    /// The generic type parameter T specifies the type of value being recorded, such as int, long, etc.
+    /// </summary>
+    /// <typeparam name="T">The type of value being measured.</typeparam>
+    public abstract class AsyncMeasurement<T> where T : struct
+    {
+        /// <summary>
+        /// Records a value.
+        /// This method is called to record a measurement value.
+        /// </summary>
+        /// <param name="value">The value to be recorded. This value is of type T.</param>
+        /// <param name="attributes">Optional attributes associated with the measurement.</param>
+        public abstract void Record(T value, Attributes attributes = null);
+    }
+}

sdk/src/Core/Amazon.Runtime/Telemetry/Metrics/AsyncMeasurementHandle.cs

@@ -0,0 +1,39 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ * 
+ *  http://aws.amazon.com/apache2.0
+ * 
+ * or in the "license" file accompanying this file. This file 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.
+ */
+
+namespace Amazon.Runtime.Telemetry.Metrics
+{
+    /// <summary>
+    /// Represents a handle for async measurements.
+    /// The handle is used to manage and stop the async recording of measurements.
+    /// </summary>
+    /// <typeparam name="T">The type of value being measured.</typeparam>
+    public abstract class AsyncMeasurementHandle<T> where T : struct
+    {
+        /// <summary>
+        /// Gets the meter that created this handle.
+        /// </summary>
+        public Meter Meter { get; protected set; }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AsyncMeasurementHandle{T}"/> class.
+        /// </summary>
+        /// <param name="meter">The meter that created this handle.</param>
+        protected AsyncMeasurementHandle(Meter meter)
+        {
+            Meter = meter;
+        }
+    }
+}

sdk/src/Core/Amazon.Runtime/Telemetry/Metrics/Histogram.cs

@@ -0,0 +1,33 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ * 
+ *  http://aws.amazon.com/apache2.0
+ * 
+ * or in the "license" file accompanying this file. This file 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.
+ */
+
+namespace Amazon.Runtime.Telemetry.Metrics
+{
+    /// <summary>
+    /// Abstract class representing a histogram used to record values of a specified type.
+    /// A histogram is a type of metric instrument that tracks the distribution of values.
+    /// </summary>
+    /// <typeparam name="T">The type of the histogram value. Must be a struct.</typeparam>
+    public abstract class Histogram<T> where T : struct
+    {
+        /// <summary>
+        /// Records a value in the histogram.
+        /// </summary>
+        /// <param name="value">The value to record. This represents a measurement or observation.</param>
+        /// <param name="attributes">Optional attributes associated with the measurement. These can be used to
+        /// provide additional context or dimensions to the recorded value.</param>
+        public abstract void Record(T value, Attributes attributes = null);
+    }
+}