refactor(telemetry): update duration metrics to seconds

Author: BenjaminAbt

src/HttpUserAgentParser/HttpUserAgentParser.cs

@@ -44,7 +44,7 @@ public static HttpUserAgentInformation Parse(string userAgent)
 
         if (measureDuration)
         {
-            HttpUserAgentParserTelemetry.ParseDuration(Stopwatch.GetElapsedTime(startTimestamp).TotalMilliseconds);
+            HttpUserAgentParserTelemetry.ParseDuration(Stopwatch.GetElapsedTime(startTimestamp));
         }
 
         return result;

src/HttpUserAgentParser/Telemetry/HttpUserAgentParserEventSource.cs

@@ -28,7 +28,7 @@ public sealed class HttpUserAgentParserEventSource : EventSource
     internal static HttpUserAgentParserEventSource Log { get; } = new();
 
     private readonly IncrementingEventCounter _parseRequests;
-    private readonly EventCounter? _parseDurationMs;
+    private readonly EventCounter? _parseDurationSeconds;
 
     private readonly IncrementingEventCounter _concurrentCacheHit;
     private readonly IncrementingEventCounter _concurrentCacheMiss;
@@ -46,10 +46,10 @@ private HttpUserAgentParserEventSource()
             DisplayUnits = "calls",
         };
 
-        _parseDurationMs = new EventCounter("parse-duration", this)
+        _parseDurationSeconds = new EventCounter("parse-duration", this)
         {
             DisplayName = "Parse duration",
-            DisplayUnits = "ms",
+            DisplayUnits = "s",
         };
 
         // Providers (cache)
@@ -92,16 +92,16 @@ internal void ParseRequest()
     /// <summary>
     /// Records the duration of a User-Agent parse operation.
     /// </summary>
-    /// <param name="milliseconds">Elapsed parse time in milliseconds.</param>
+    /// <param name="seconds">Elapsed parse time in seconds.</param>
     [NonEvent]
-    internal void ParseDuration(double milliseconds)
+    internal void ParseDuration(double seconds)
     {
         if (!IsEnabled())
         {
             return;
         }
 
-        _parseDurationMs?.WriteMetric(milliseconds);
+        _parseDurationSeconds?.WriteMetric(seconds);
     }
 
     /// <summary>
@@ -155,7 +155,7 @@ protected override void Dispose(bool disposing)
         if (disposing)
         {
             _parseRequests?.Dispose();
-            _parseDurationMs?.Dispose();
+            _parseDurationSeconds?.Dispose();
 
             _concurrentCacheHit?.Dispose();
             _concurrentCacheMiss?.Dispose();

src/HttpUserAgentParser/Telemetry/HttpUserAgentParserMeters.cs

@@ -63,11 +63,9 @@ public static void Enable(Meter? meter = null)
             unit: "{call}",
             description: "User-Agent parse requests");
 
-        // Using "ms" instead of "s" because parse times are sub-millisecond,
-        // making milliseconds more readable than fractional seconds.
         s_parseDuration = s_meter.CreateHistogram<double>(
             name: "parse.duration",
-            unit: "ms",
+            unit: "s",
             description: "Parse duration");
 
         s_concurrentCacheHit = s_meter.CreateCounter<long>(
@@ -94,10 +92,10 @@ public static void Enable(Meter? meter = null)
     public static void ParseRequest() => s_parseRequests?.Add(1);
 
     /// <summary>
-    /// Records the parse duration in milliseconds.
+    /// Records the parse duration in seconds.
     /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public static void ParseDuration(double milliseconds) => s_parseDuration?.Record(milliseconds);
+    public static void ParseDuration(double seconds) => s_parseDuration?.Record(seconds);
 
     /// <summary>
     /// Emits a counter increment for a concurrent dictionary cache hit.

src/HttpUserAgentParser/Telemetry/HttpUserAgentParserTelemetry.cs

@@ -92,19 +92,19 @@ public static void ParseRequest()
     /// <summary>
     /// Records the duration of a parse request.
     /// </summary>
-    /// <param name="milliseconds">The duration in milliseconds.</param>
+    /// <param name="duration">The elapsed duration.</param>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public static void ParseDuration(double milliseconds)
+    public static void ParseDuration(TimeSpan duration)
     {
         int flags = Volatile.Read(ref s_enabledFlags);
         if ((flags & EventCountersFlag) != 0)
         {
-            HttpUserAgentParserEventSource.Log.ParseDuration(milliseconds);
+            HttpUserAgentParserEventSource.Log.ParseDuration(duration.TotalSeconds);
         }
 
         if ((flags & MetersFlag) != 0)
         {
-            HttpUserAgentParserMeters.ParseDuration(milliseconds);
+            HttpUserAgentParserMeters.ParseDuration(duration.TotalSeconds);
         }
     }
 

tests/HttpUserAgentParser.UnitTests/Telemetry/HttpUserAgentParserMetersTelemetryTests.cs

@@ -48,5 +48,7 @@ public void Meters_Emit_WhenEnabled()
         Assert.Contains("cache.concurrent_dictionary.hit", listener.InstrumentNames);
         Assert.Contains("cache.concurrent_dictionary.miss", listener.InstrumentNames);
         Assert.Contains("cache.concurrent_dictionary.size", listener.InstrumentNames);
+
+        Assert.Equal("s", listener.InstrumentUnits["parse.duration"]);
     }
 }

tests/HttpUserAgentParser.UnitTests/Telemetry/MeterTestListener.cs

@@ -11,6 +11,7 @@ internal sealed class MeterTestListener : IDisposable
     private readonly MeterListener _listener;
 
     public ConcurrentBag<string> InstrumentNames { get; } = [];
+    public ConcurrentDictionary<string, string?> InstrumentUnits { get; } = new(StringComparer.Ordinal);
 
     public MeterTestListener(string meterName)
     {
@@ -24,6 +25,7 @@ public MeterTestListener(string meterName)
                 return;
             }
 
+            InstrumentUnits[instrument.Name] = instrument.Unit;
             listener.EnableMeasurementEvents(instrument);
         };