[otlp] Rename key for enabling retries during transient failures

src/OpenTelemetry.Exporter.OpenTelemetryProtocol/CHANGELOG.md

@@ -10,6 +10,12 @@
   is not required to be set [when using .NET 5 or newer](https://learn.microsoft.com/aspnet/core/grpc/troubleshoot?view=aspnetcore-8.0#call-insecure-grpc-services-with-net-core-client).
   ([#5486](https://github.com/open-telemetry/opentelemetry-dotnet/pull/5486))
 
+* **Removed** `OTEL_DOTNET_EXPERIMENTAL_OTLP_ENABLE_INMEMORY_RETRY` and added
+  `OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY`. `OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY`
+  when set to `in_memory` will enable automatic retries in case of transient
+  failures during data export to otlp endpoint.
+  ([#5495](https://github.com/open-telemetry/opentelemetry-dotnet/pull/5495))
+
 ## 1.8.0-rc.1
 
 Released 2024-Mar-27

src/OpenTelemetry.Exporter.OpenTelemetryProtocol/Implementation/ExperimentalOptions.cs

@@ -15,7 +15,7 @@ internal sealed class ExperimentalOptions
 
     public const string EmitLogEventEnvVar = "OTEL_DOTNET_EXPERIMENTAL_OTLP_EMIT_EVENT_LOG_ATTRIBUTES";
 
-    public const string EnableInMemoryRetryEnvVar = "OTEL_DOTNET_EXPERIMENTAL_OTLP_ENABLE_INMEMORY_RETRY";
+    public const string OtlpRetryEnvVar = "OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY";
 
     public ExperimentalOptions()
         : this(new ConfigurationBuilder().AddEnvironmentVariables().Build())
@@ -29,9 +29,9 @@ public ExperimentalOptions(IConfiguration configuration)
             this.EmitLogEventAttributes = emitLogEventAttributes;
         }
 
-        if (configuration.TryGetBoolValue(OpenTelemetryProtocolExporterEventSource.Log, EnableInMemoryRetryEnvVar, out var enableInMemoryRetry))
+        if (configuration.TryGetStringValue(OpenTelemetryProtocolExporterEventSource.Log, OtlpRetryEnvVar, out var retryPolicy) && retryPolicy != null && retryPolicy.Equals("in_memory", StringComparison.OrdinalIgnoreCase))
         {
-            this.EnableInMemoryRetry = enableInMemoryRetry;
+            this.EnableInMemoryRetry = true;
         }
     }
 

src/OpenTelemetry.Exporter.OpenTelemetryProtocol/README.md

@@ -625,9 +625,9 @@ want to solicit feedback from the community.
 
 * All signals
 
-  * `OTEL_DOTNET_EXPERIMENTAL_OTLP_ENABLE_INMEMORY_RETRY`
+  * `OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY`
 
-    When set to `true`, it enables in-memory retry for transient errors
+    When set to `in_memory`, it enables in-memory retry for transient errors
     encountered while sending telemetry.
 
     Added in `1.8.0-beta.1`.

src/Shared/Configuration/OpenTelemetryConfigurationExtensions.cs

@@ -107,6 +107,24 @@ public static bool TryGetBoolValue(
         return true;
     }
 
+    public static bool TryGetStringValue(
+       this IConfiguration configuration,
+       IConfigurationExtensionsLogger logger,
+       string key,
+       out string? value)
+    {
+        Debug.Assert(logger != null, "logger was null");
+
+        if (!configuration.TryGetStringValue(key, out var stringValue))
+        {
+            value = null;
+            return false;
+        }
+
+        value = stringValue;
+        return true;
+    }
+
     public static bool TryGetValue<T>(
         this IConfiguration configuration,
         IConfigurationExtensionsLogger logger,

test/OpenTelemetry.Exporter.OpenTelemetryProtocol.Tests/MockCollectorIntegrationTests.cs

@@ -179,7 +179,7 @@ public async Task GrpcRetryTests(bool useRetryTransmissionHandler, ExportResult
         var exporterOptions = new OtlpExporterOptions() { Endpoint = endpoint, TimeoutMilliseconds = 20000, Protocol = OtlpExportProtocol.Grpc };
 
         var configuration = new ConfigurationBuilder()
-         .AddInMemoryCollection(new Dictionary<string, string> { [ExperimentalOptions.EnableInMemoryRetryEnvVar] = useRetryTransmissionHandler.ToString() })
+         .AddInMemoryCollection(new Dictionary<string, string> { [ExperimentalOptions.OtlpRetryEnvVar] = useRetryTransmissionHandler ? "in_memory" : null })
          .Build();
 
         var otlpExporter = new OtlpTraceExporter(exporterOptions, new SdkLimitOptions(), new ExperimentalOptions(configuration));
@@ -263,7 +263,7 @@ public async Task HttpRetryTests(bool useRetryTransmissionHandler, ExportResult
         var exporterOptions = new OtlpExporterOptions() { Endpoint = endpoint, TimeoutMilliseconds = 20000, Protocol = OtlpExportProtocol.HttpProtobuf };
 
         var configuration = new ConfigurationBuilder()
-         .AddInMemoryCollection(new Dictionary<string, string> { [ExperimentalOptions.EnableInMemoryRetryEnvVar] = useRetryTransmissionHandler.ToString() })
+         .AddInMemoryCollection(new Dictionary<string, string> { [ExperimentalOptions.OtlpRetryEnvVar] = useRetryTransmissionHandler ? "in_memory" : null })
          .Build();
 
         var otlpExporter = new OtlpTraceExporter(exporterOptions, new SdkLimitOptions(), new ExperimentalOptions(configuration));