Use the same naming rules for the names of logging dimensions

src/Generators/Microsoft.Gen.Logging/Emission/Emitter.Method.cs

@@ -316,7 +316,7 @@ void GenPropertyLoads(LoggingMethod lm, string stateName, out int numReservedUnc
                         {
                             if (!member.HasDataClassification)
                             {
-                                var propName = PropertyChainToString(propertyChain, member, "_", omitReferenceName: p.OmitReferenceName);
+                                var propName = PropertyChainToString(propertyChain, member, ".", omitReferenceName: p.OmitReferenceName);
                                 var accessExpression = PropertyChainToString(propertyChain, member, "?.", nonNullSeparator: ".");
 
                                 var ts = ShouldStringifyProperty(member)
@@ -367,7 +367,7 @@ void GenPropertyLoads(LoggingMethod lm, string stateName, out int numReservedUnc
                         {
                             if (member.HasDataClassification)
                             {
-                                var propName = PropertyChainToString(propertyChain, member, "_", omitReferenceName: p.OmitReferenceName);
+                                var propName = PropertyChainToString(propertyChain, member, ".", omitReferenceName: p.OmitReferenceName);
                                 var accessExpression = PropertyChainToString(propertyChain, member, "?.", nonNullSeparator: ".");
 
                                 var value = ShouldStringifyProperty(member)
@@ -391,7 +391,7 @@ void GenPropertyLoads(LoggingMethod lm, string stateName, out int numReservedUnc
                     {
                         if (member.HasDataClassification)
                         {
-                            var propName = PropertyChainToString(propertyChain, member, "_", omitReferenceName: p.OmitReferenceName);
+                            var propName = PropertyChainToString(propertyChain, member, ".", omitReferenceName: p.OmitReferenceName);
                             var accessExpression = PropertyChainToString(propertyChain, member, "?.", nonNullSeparator: ".");
 
                             var value = ShouldStringifyProperty(member)
@@ -418,7 +418,7 @@ void GenPropertyLoads(LoggingMethod lm, string stateName, out int numReservedUnc
                         }
                         else
                         {
-                            var propName = PropertyChainToString(propertyChain, member, "_", omitReferenceName: p.OmitReferenceName);
+                            var propName = PropertyChainToString(propertyChain, member, ".", omitReferenceName: p.OmitReferenceName);
                             var accessExpression = PropertyChainToString(propertyChain, member, "?.", nonNullSeparator: ".");
 
                             var ts = ShouldStringifyProperty(member)

src/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware/Logging/HeaderNormalizer.cs

@@ -0,0 +1,28 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using Microsoft.Extensions.Compliance.Classification;
+
+internal static class HeaderNormalizer
+{
+    public static string[] PrepareNormalizedHeaderNames(KeyValuePair<string, DataClassification>[] headers, string prefix)
+    {
+        var normalizedHeaders = new string[headers.Length];
+
+        for (int i = 0; i < headers.Length; i++)
+        {
+            normalizedHeaders[i] = prefix + Normalize(headers[i].Key);
+        }
+
+        return normalizedHeaders;
+    }
+
+    [SuppressMessage("Globalization", "CA1308:Normalize strings to uppercase",
+        Justification = "Normalization to lower case is required by OTel's semantic conventions")]
+    private static string Normalize(string header)
+    {
+        return header.ToLowerInvariant();
+    }
+}

src/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware/Logging/HeaderReader.cs

@@ -16,28 +16,32 @@ internal sealed class HeaderReader
 {
     private readonly IRedactorProvider _redactorProvider;
     private readonly KeyValuePair<string, DataClassification>[] _headers;
+    private readonly string[] _normalizedHeaders;
 
-    public HeaderReader(IDictionary<string, DataClassification> headersToLog, IRedactorProvider redactorProvider)
+    public HeaderReader(IDictionary<string, DataClassification> headersToLog, IRedactorProvider redactorProvider, string prefix)
     {
         _redactorProvider = redactorProvider;
 
         _headers = headersToLog.Count == 0 ? [] : headersToLog.ToArray();
+        _normalizedHeaders = HeaderNormalizer.PrepareNormalizedHeaderNames(_headers, prefix);
     }
 
-    public void Read(IHeaderDictionary headers, IList<KeyValuePair<string, object?>> logContext, string prefix)
+    public void Read(IHeaderDictionary headers, IList<KeyValuePair<string, object?>> logContext)
     {
         if (headers.Count == 0)
         {
             return;
         }
 
-        foreach (var header in _headers)
+        for (int i = 0; i < _headers.Length; i++)
         {
+            var header = _headers[i];
+
             if (headers.TryGetValue(header.Key, out var headerValue))
             {
                 var provider = _redactorProvider.GetRedactor(header.Value);
                 var redacted = provider.Redact(headerValue.ToString());
-                logContext.Add(new(prefix + header.Key, redacted));
+                logContext.Add(new(_normalizedHeaders[i], redacted));
             }
         }
     }

src/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware/Logging/HttpLoggingRedactionInterceptor.cs

@@ -55,8 +55,8 @@ public HttpLoggingRedactionInterceptor(
         _requestPathLogMode = EnsureRequestPathLoggingModeIsValid(optionsValue.RequestPathLoggingMode);
         _parameterRedactionMode = optionsValue.RequestPathParameterRedactionMode;
 
-        _requestHeadersReader = new(optionsValue.RequestHeadersDataClasses, redactorProvider);
-        _responseHeadersReader = new(optionsValue.ResponseHeadersDataClasses, redactorProvider);
+        _requestHeadersReader = new(optionsValue.RequestHeadersDataClasses, redactorProvider, HttpLoggingTagNames.RequestHeaderPrefix);
+        _responseHeadersReader = new(optionsValue.ResponseHeadersDataClasses, redactorProvider, HttpLoggingTagNames.ResponseHeaderPrefix);
 
         _excludePathStartsWith = optionsValue.ExcludePathStartsWith.ToArray();
     }
@@ -126,7 +126,7 @@ public ValueTask OnRequestAsync(HttpLoggingInterceptorContext logContext)
 
         if (logContext.TryDisable(HttpLoggingFields.RequestHeaders))
         {
-            _requestHeadersReader.Read(context.Request.Headers, logContext.Parameters, HttpLoggingTagNames.RequestHeaderPrefix);
+            _requestHeadersReader.Read(context.Request.Headers, logContext.Parameters);
         }
 
         return default;
@@ -138,7 +138,7 @@ public ValueTask OnResponseAsync(HttpLoggingInterceptorContext logContext)
 
         if (logContext.TryDisable(HttpLoggingFields.ResponseHeaders))
         {
-            _responseHeadersReader.Read(context.Response.Headers, logContext.Parameters, HttpLoggingTagNames.ResponseHeaderPrefix);
+            _responseHeadersReader.Read(context.Response.Headers, logContext.Parameters);
         }
 
         // Don't enrich if we're not going to log any part of the response

src/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware/Logging/HttpLoggingTagNames.cs

@@ -19,7 +19,7 @@ public static class HttpLoggingTagNames
     /// <summary>
     /// HTTP Host.
     /// </summary>
-    public const string Host = "Host";
+    public const string Host = "server.address";
 
     /// <summary>
     /// HTTP Method.
@@ -34,12 +34,12 @@ public static class HttpLoggingTagNames
     /// <summary>
     /// HTTP Request Headers prefix.
     /// </summary>
-    public const string RequestHeaderPrefix = "RequestHeader.";
+    public const string RequestHeaderPrefix = "http.request.header.";
 
     /// <summary>
     /// HTTP Response Headers prefix.
     /// </summary>
-    public const string ResponseHeaderPrefix = "ResponseHeader.";
+    public const string ResponseHeaderPrefix = "http.response.header.";
 
     /// <summary>
     /// HTTP Request Body.

src/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware/Logging/RequestHeadersLogEnricher.cs

@@ -2,7 +2,8 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
-using System.Collections.Frozen;
+using System.Collections.Generic;
+using System.Linq;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Compliance.Classification;
 using Microsoft.Extensions.Compliance.Redaction;
@@ -17,7 +18,8 @@ namespace Microsoft.AspNetCore.Diagnostics.Logging;
 /// </summary>
 internal sealed class RequestHeadersLogEnricher : ILogEnricher
 {
-    private readonly FrozenDictionary<string, DataClassification> _headersDataClasses;
+    private readonly KeyValuePair<string, DataClassification>[] _headersDataClasses;
+    private readonly string[] _normalizedHeaders;
     private readonly IHttpContextAccessor _httpContextAccessor;
     private readonly IRedactorProvider? _redactorProvider;
 
@@ -33,11 +35,10 @@ public RequestHeadersLogEnricher(IHttpContextAccessor httpContextAccessor, IOpti
         var opt = Throw.IfMemberNull(options, options.Value);
         _httpContextAccessor = httpContextAccessor;
 
-        _headersDataClasses = opt.HeadersDataClasses.Count == 0
-            ? FrozenDictionary<string, DataClassification>.Empty
-            : opt.HeadersDataClasses.ToFrozenDictionary(StringComparer.Ordinal);
+        _headersDataClasses = opt.HeadersDataClasses.Count == 0 ? [] : opt.HeadersDataClasses.ToArray();
+        _normalizedHeaders = HeaderNormalizer.PrepareNormalizedHeaderNames(_headersDataClasses, HttpLoggingTagNames.RequestHeaderPrefix);
 
-        if (_headersDataClasses.Count > 0)
+        if (_headersDataClasses.Length > 0)
         {
             _redactorProvider = Throw.IfNull(redactorProvider);
         }
@@ -54,20 +55,22 @@ public void Enrich(IEnrichmentTagCollector collector)
 
             var request = _httpContextAccessor.HttpContext.Request;
 
-            if (_headersDataClasses.Count == 0)
+            if (_headersDataClasses.Length == 0)
             {
                 return;
             }
 
-            if (_headersDataClasses.Count != 0)
+            if (_headersDataClasses.Length != 0)
             {
-                foreach (var header in _headersDataClasses)
+                for (int i = 0; i < _headersDataClasses.Length; i++)
                 {
+                    var header = _headersDataClasses[i];
+
                     if (request.Headers.TryGetValue(header.Key, out var headerValue) && !string.IsNullOrEmpty(headerValue))
                     {
                         var redactor = _redactorProvider!.GetRedactor(header.Value);
                         var redacted = redactor.Redact(headerValue);
-                        collector.Add(header.Key, redacted);
+                        collector.Add(_normalizedHeaders[i], redacted);
                     }
                 }
             }

src/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware/Microsoft.AspNetCore.Diagnostics.Middleware.json

@@ -31,7 +31,7 @@
         {
           "Member": "const string Microsoft.AspNetCore.Diagnostics.Logging.HttpLoggingTagNames.Host",
           "Stage": "Stable",
-          "Value": "Host"
+          "Value": "server.address"
         },
         {
           "Member": "const string Microsoft.AspNetCore.Diagnostics.Logging.HttpLoggingTagNames.Method",
@@ -51,7 +51,7 @@
         {
           "Member": "const string Microsoft.AspNetCore.Diagnostics.Logging.HttpLoggingTagNames.RequestHeaderPrefix",
           "Stage": "Stable",
-          "Value": "RequestHeader."
+          "Value": "http.request.header."
         },
         {
           "Member": "const string Microsoft.AspNetCore.Diagnostics.Logging.HttpLoggingTagNames.ResponseBody",
@@ -61,7 +61,7 @@
         {
           "Member": "const string Microsoft.AspNetCore.Diagnostics.Logging.HttpLoggingTagNames.ResponseHeaderPrefix",
           "Stage": "Stable",
-          "Value": "ResponseHeader."
+          "Value": "http.response.header."
         },
         {
           "Member": "const string Microsoft.AspNetCore.Diagnostics.Logging.HttpLoggingTagNames.StatusCode",

src/Libraries/Microsoft.AspNetCore.HeaderParsing/HeaderParsingFeature.cs

@@ -198,12 +198,12 @@ private void CopyTo(Box<T> to)
         }
     }
 
-    [LoggerMessage(LogLevel.Debug, "Can't parse header '{headerName}' due to '{error}'.")]
+    [LoggerMessage(LogLevel.Debug, "Can't parse header '{HeaderName}' due to '{Error}'.")]
     private partial void LogParsingError(string headerName, string error);
 
-    [LoggerMessage(LogLevel.Debug, "Using a default value for header '{headerName}'.")]
+    [LoggerMessage(LogLevel.Debug, "Using a default value for header '{HeaderName}'.")]
     private partial void LogDefaultUsage(string headerName);
 
-    [LoggerMessage(LogLevel.Debug, "Header '{headerName}' not found.")]
+    [LoggerMessage(LogLevel.Debug, "Header '{HeaderName}' not found.")]
     private partial void LogNotFound(string headerName);
 }

src/Libraries/Microsoft.Extensions.Diagnostics.Extra/Enrichment/ApplicationEnricherTags.cs

@@ -14,22 +14,22 @@ public static class ApplicationEnricherTags
     /// <summary>
     /// Application name.
     /// </summary>
-    public const string ApplicationName = "AppName";
+    public const string ApplicationName = "service.name";
 
     /// <summary>
     /// Environment name.
     /// </summary>
-    public const string EnvironmentName = "CloudEnv";
+    public const string EnvironmentName = "deployment.environment";
 
     /// <summary>
     /// Deployment ring.
     /// </summary>
-    public const string DeploymentRing = "CloudDeploymentRing";
+    public const string DeploymentRing = "DeploymentRing";
 
     /// <summary>
     /// Build version.
     /// </summary>
-    public const string BuildVersion = "CloudRoleVer";
+    public const string BuildVersion = "service.version";
 
     /// <summary>
     /// Gets a list of all dimension names.

src/Libraries/Microsoft.Extensions.Diagnostics.Extra/Enrichment/ProcessEnricherTagNames.cs

@@ -14,12 +14,12 @@ public static class ProcessEnricherTagNames
     /// <summary>
     /// Process ID.
     /// </summary>
-    public const string ProcessId = "pid";
+    public const string ProcessId = "process.pid";
 
     /// <summary>
     /// Thread ID.
     /// </summary>
-    public const string ThreadId = "tid";
+    public const string ThreadId = "thread.id";
 
     /// <summary>
     /// Gets a list of all dimension names.

src/Libraries/Microsoft.Extensions.Diagnostics.Extra/Microsoft.Extensions.Diagnostics.Extra.json

@@ -26,22 +26,22 @@
         {
           "Member": "const string Microsoft.Extensions.Diagnostics.Enrichment.ApplicationEnricherTags.ApplicationName",
           "Stage": "Stable",
-          "Value": "AppName"
+          "Value": "service.name"
         },
         {
           "Member": "const string Microsoft.Extensions.Diagnostics.Enrichment.ApplicationEnricherTags.BuildVersion",
           "Stage": "Stable",
-          "Value": "CloudRoleVer"
+          "Value": "service.version"
         },
         {
           "Member": "const string Microsoft.Extensions.Diagnostics.Enrichment.ApplicationEnricherTags.DeploymentRing",
           "Stage": "Stable",
-          "Value": "CloudDeploymentRing"
+          "Value": "DeploymentRing"
         },
         {
           "Member": "const string Microsoft.Extensions.Diagnostics.Enrichment.ApplicationEnricherTags.EnvironmentName",
           "Stage": "Stable",
-          "Value": "CloudEnv"
+          "Value": "deployment.environment"
         }
       ],
       "Properties": [
@@ -260,12 +260,12 @@
         {
           "Member": "const string Microsoft.Extensions.Diagnostics.Enrichment.ProcessEnricherTagNames.ProcessId",
           "Stage": "Stable",
-          "Value": "pid"
+          "Value": "process.pid"
         },
         {
           "Member": "const string Microsoft.Extensions.Diagnostics.Enrichment.ProcessEnricherTagNames.ThreadId",
           "Stage": "Stable",
-          "Value": "tid"
+          "Value": "thread.id"
         }
       ],
       "Properties": [

src/Libraries/Microsoft.Extensions.Diagnostics.ExtraAbstractions/Logging/LoggerMessageState.TagCollector.cs

@@ -7,7 +7,7 @@ namespace Microsoft.Extensions.Logging;
 
 public partial class LoggerMessageState : ITagCollector
 {
-    private const char Separator = '_';
+    private const char Separator = '.';
 
     /// <inheritdoc />
     void ITagCollector.Add(string tagName, object? tagValue)

src/Libraries/Microsoft.Extensions.Diagnostics.HealthChecks.Common/Log.cs

@@ -8,13 +8,13 @@ namespace Microsoft.Extensions.Diagnostics.HealthChecks;
 
 internal static partial class Log
 {
-    [LoggerMessage(0, LogLevel.Warning, "Process reporting unhealthy: {status}. Health check entries are {entries}")]
+    [LoggerMessage(0, LogLevel.Warning, "Process reporting unhealthy: {Status}. Health check entries are {Entries}")]
     public static partial void Unhealthy(
         ILogger logger,
         HealthStatus status,
         StringBuilder entries);
 
-    [LoggerMessage(1, LogLevel.Debug, "Process reporting healthy: {status}.")]
+    [LoggerMessage(1, LogLevel.Debug, "Process reporting healthy: {Status}.")]
     public static partial void Healthy(
         ILogger logger,
         HealthStatus status);

src/Libraries/Microsoft.Extensions.Diagnostics.ResourceMonitoring/Log.cs

@@ -14,6 +14,6 @@ internal static partial class Log
     [LoggerMessage(1, LogLevel.Error, "Unable to gather utilization statistics.")]
     public static partial void HandledGatherStatisticsException(ILogger logger, Exception e);
 
-    [LoggerMessage(2, LogLevel.Error, "Publisher `{publisher}` was unable to publish utilization statistics.")]
+    [LoggerMessage(2, LogLevel.Error, "Publisher `{Publisher}` was unable to publish utilization statistics.")]
     public static partial void HandlePublishUtilizationException(ILogger logger, Exception e, string publisher);
 }

src/Libraries/Microsoft.Extensions.Hosting.Testing/HostTerminatorService.cs

@@ -60,7 +60,7 @@ protected override async Task ExecuteAsync(CancellationToken stoppingToken)
         _host.Dispose();
     }
 
-    [LoggerMessage(0, LogLevel.Warning, "FakeHostOptions.TimeToLive set to {timeToLive} is up, disposing the host.")]
+    [LoggerMessage(0, LogLevel.Warning, "FakeHostOptions.TimeToLive set to {TimeToLive} is up, disposing the host.")]
     private partial void LogTimeToLiveUp(TimeSpan timeToLive);
 
     [LoggerMessage(1, LogLevel.Information, "Debugger is attached. The host won't be automatically disposed.")]

src/Libraries/Microsoft.Extensions.Http.Diagnostics/Latency/Internal/HttpClientLatencyLogEnricher.cs

@@ -50,7 +50,7 @@ public void Enrich(IEnrichmentTagCollector collector, HttpRequestMessage request
                 AppendCheckpoints(lc, stringBuilder);
             }
 
-            collector.Add("latencyInfo", stringBuilder.ToString());
+            collector.Add("LatencyInfo", stringBuilder.ToString());
 
             _builderPool.Return(stringBuilder);
         }