Adds .NET distributed tracing instrumentation & metrics.

src/FirebirdSql.Data.FirebirdClient.Tests/FbTransactionTests.cs

@@ -139,4 +139,22 @@ public async Task SnapshotAtNumber()
 			}
 		}
 	}
+
+	[Test]
+	public async Task CanGetTransactionId()
+	{
+		if (!EnsureServerVersionAtLeast(new Version(2, 5, 0, 0)))
+			return;
+
+		await using (var transaction1 = await Connection.BeginTransactionAsync())
+		{
+			var idFromInfo = await new FbTransactionInfo(transaction1).GetTransactionIdAsync();
+			Assert.NotZero(idFromInfo);
+
+			var command = new FbCommand("SELECT current_transaction FROM rdb$database", Connection, transaction1);
+			var idFromSql = await command.ExecuteScalarAsync();
+
+			Assert.AreEqual(idFromInfo, idFromSql);
+		}
+	}
 }

src/FirebirdSql.Data.FirebirdClient/Common/IscHelper.cs

@@ -206,6 +206,10 @@ public static List<object> ParseTransactionInfo(byte[] buffer, Charset charset)
 				case IscCodes.isc_info_error:
 					throw FbException.Create("Received error response.");
 
+				case IscCodes.isc_info_tra_id:
+					info.Add(VaxInteger(buffer, pos, length));
+					break;
+
 				case IscCodes.fb_info_tra_snapshot_number:
 					info.Add(VaxInteger(buffer, pos, length));
 					break;

src/FirebirdSql.Data.FirebirdClient/FirebirdClient/FbCommand.cs

@@ -20,11 +20,14 @@
 using System.ComponentModel;
 using System.Data;
 using System.Data.Common;
+using System.Diagnostics;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using FirebirdSql.Data.Common;
 using FirebirdSql.Data.Logging;
+using FirebirdSql.Data.Metrics;
+using FirebirdSql.Data.Trace;
 
 namespace FirebirdSql.Data.FirebirdClient;
 
@@ -49,6 +52,8 @@ public sealed class FbCommand : DbCommand, IFbPreparedCommand, IDescriptorFiller
 	private int? _commandTimeout;
 	private int _fetchSize;
 	private Type[] _expectedColumnTypes;
+	private Activity _currentActivity;
+	private long _startedAtTicks;
 
 	#endregion
 
@@ -1094,7 +1099,10 @@ internal void Release()
 			_statement.Dispose2();
 			_statement = null;
 		}
+
+		TraceCommandStop();
 	}
+
 	Task IFbPreparedCommand.ReleaseAsync(CancellationToken cancellationToken) => ReleaseAsync(cancellationToken);
 	internal async Task ReleaseAsync(CancellationToken cancellationToken = default)
 	{
@@ -1112,6 +1120,8 @@ internal async Task ReleaseAsync(CancellationToken cancellationToken = default)
 			await _statement.Dispose2Async(cancellationToken).ConfigureAwait(false);
 			_statement = null;
 		}
+
+		TraceCommandStop();
 	}
 
 	void IFbPreparedCommand.TransactionCompleted() => TransactionCompleted();
@@ -1332,6 +1342,41 @@ private async ValueTask UpdateParameterValuesAsync(Descriptor descriptor, Cancel
 
 	#endregion
 
+	#region Tracing
+
+	private void TraceCommandStart()
+	{
+		Debug.Assert(_currentActivity == null);
+		if (FbActivitySource.Source.HasListeners())
+			_currentActivity = FbActivitySource.CommandStart(this);
+
+		_startedAtTicks = FbMetricsStore.CommandStart();
+	}
+
+	private void TraceCommandStop()
+	{
+		if (_currentActivity != null)
+		{
+			// Do not set status to Ok: https://opentelemetry.io/docs/concepts/signals/traces/#span-status
+			_currentActivity.Dispose();
+			_currentActivity = null;
+		}
+
+		FbMetricsStore.CommandStop(_startedAtTicks, Connection);
+		_startedAtTicks = 0;
+	}
+
+	private void TraceCommandException(Exception e)
+	{
+		if (_currentActivity != null)
+		{
+			FbActivitySource.CommandException(_currentActivity, e);
+			_currentActivity = null;
+		}
+	}
+
+	#endregion Tracing
+
 	#region Private Methods
 
 	private void Prepare(bool returnsSet)
@@ -1476,57 +1521,73 @@ private async Task PrepareAsync(bool returnsSet, CancellationToken cancellationT
 	private void ExecuteCommand(CommandBehavior behavior, bool returnsSet)
 	{
 		LogMessages.CommandExecution(Log, this);
+		TraceCommandStart();
+		try
+		{
+			Prepare(returnsSet);
 
-		Prepare(returnsSet);
+			if ((behavior & CommandBehavior.SequentialAccess) == CommandBehavior.SequentialAccess ||
+				(behavior & CommandBehavior.SingleResult) == CommandBehavior.SingleResult ||
+				(behavior & CommandBehavior.SingleRow) == CommandBehavior.SingleRow ||
+				(behavior & CommandBehavior.CloseConnection) == CommandBehavior.CloseConnection ||
+				behavior == CommandBehavior.Default)
+			{
+				// Set the fetch size
+				_statement.FetchSize = _fetchSize;
 
-		if ((behavior & CommandBehavior.SequentialAccess) == CommandBehavior.SequentialAccess ||
-			(behavior & CommandBehavior.SingleResult) == CommandBehavior.SingleResult ||
-			(behavior & CommandBehavior.SingleRow) == CommandBehavior.SingleRow ||
-			(behavior & CommandBehavior.CloseConnection) == CommandBehavior.CloseConnection ||
-			behavior == CommandBehavior.Default)
-		{
-			// Set the fetch size
-			_statement.FetchSize = _fetchSize;
+				// Set if it's needed the Records Affected information
+				_statement.ReturnRecordsAffected = _connection.ConnectionOptions.ReturnRecordsAffected;
 
-			// Set if it's needed the Records Affected information
-			_statement.ReturnRecordsAffected = _connection.ConnectionOptions.ReturnRecordsAffected;
+				// Validate input parameter count
+				if (_namedParameters.Count > 0 && !HasParameters)
+				{
+					throw FbException.Create("Must declare command parameters.");
+				}
 
-			// Validate input parameter count
-			if (_namedParameters.Count > 0 && !HasParameters)
-			{
-				throw FbException.Create("Must declare command parameters.");
+				// Execute
+				_statement.Execute(CommandTimeout * 1000, this);
 			}
-
-			// Execute
-			_statement.Execute(CommandTimeout * 1000, this);
+		}
+		catch (Exception e)
+		{
+			TraceCommandException(e);
+			throw;
 		}
 	}
 	private async Task ExecuteCommandAsync(CommandBehavior behavior, bool returnsSet, CancellationToken cancellationToken = default)
 	{
 		LogMessages.CommandExecution(Log, this);
+		TraceCommandStart();
+		try
+		{
+			await PrepareAsync(returnsSet, cancellationToken).ConfigureAwait(false);
 
-		await PrepareAsync(returnsSet, cancellationToken).ConfigureAwait(false);
+			if ((behavior & CommandBehavior.SequentialAccess) == CommandBehavior.SequentialAccess ||
+				(behavior & CommandBehavior.SingleResult) == CommandBehavior.SingleResult ||
+				(behavior & CommandBehavior.SingleRow) == CommandBehavior.SingleRow ||
+				(behavior & CommandBehavior.CloseConnection) == CommandBehavior.CloseConnection ||
+				behavior == CommandBehavior.Default)
+			{
+				// Set the fetch size
+				_statement.FetchSize = _fetchSize;
 
-		if ((behavior & CommandBehavior.SequentialAccess) == CommandBehavior.SequentialAccess ||
-			(behavior & CommandBehavior.SingleResult) == CommandBehavior.SingleResult ||
-			(behavior & CommandBehavior.SingleRow) == CommandBehavior.SingleRow ||
-			(behavior & CommandBehavior.CloseConnection) == CommandBehavior.CloseConnection ||
-			behavior == CommandBehavior.Default)
-		{
-			// Set the fetch size
-			_statement.FetchSize = _fetchSize;
+				// Set if it's needed the Records Affected information
+				_statement.ReturnRecordsAffected = _connection.ConnectionOptions.ReturnRecordsAffected;
 
-			// Set if it's needed the Records Affected information
-			_statement.ReturnRecordsAffected = _connection.ConnectionOptions.ReturnRecordsAffected;
+				// Validate input parameter count
+				if (_namedParameters.Count > 0 && !HasParameters)
+				{
+					throw FbException.Create("Must declare command parameters.");
+				}
 
-			// Validate input parameter count
-			if (_namedParameters.Count > 0 && !HasParameters)
-			{
-				throw FbException.Create("Must declare command parameters.");
+				// Execute
+				await _statement.ExecuteAsync(CommandTimeout * 1000, this, cancellationToken).ConfigureAwait(false);
 			}
-
-			// Execute
-			await _statement.ExecuteAsync(CommandTimeout * 1000, this, cancellationToken).ConfigureAwait(false);
+		}
+		catch (Exception e)
+		{
+			TraceCommandException(e);
+			throw;
 		}
 	}
 

src/FirebirdSql.Data.FirebirdClient/FirebirdClient/FbConnection.cs

@@ -16,13 +16,15 @@
 //$Authors = Carlos Guzman Alvarez, Jiri Cincura ([email protected])
 
 using System;
+using System.Collections.Generic;
 using System.ComponentModel;
 using System.Data;
 using System.Data.Common;
 using System.Threading;
 using System.Threading.Tasks;
 using FirebirdSql.Data.Common;
 using FirebirdSql.Data.Logging;
+using FirebirdSql.Data.Metrics;
 
 namespace FirebirdSql.Data.FirebirdClient;
 
@@ -189,6 +191,12 @@ public override string ConnectionString
 				_options = new ConnectionString(value);
 				_options.Validate();
 				_connectionString = value;
+
+				MetricsConnectionAttributes = [
+					new("db.system", "firebird"),
+					new("db.namespace", _options.Database),
+					new("server.address", $"{_options.DataSource}:{_options.Port}")
+				];
 			}
 		}
 	}
@@ -269,6 +277,8 @@ internal bool IsClosed
 		get { return _state == ConnectionState.Closed; }
 	}
 
+	internal KeyValuePair<string, object>[] MetricsConnectionAttributes;
+
 	#endregion
 
 	#region Protected Properties
@@ -553,6 +563,7 @@ public override async Task ChangeDatabaseAsync(string databaseName, Cancellation
 	public override void Open()
 	{
 		LogMessages.ConnectionOpening(Log, this);
+		var startedAtTicks = FbMetricsStore.ConnectionOpening();
 
 		if (string.IsNullOrEmpty(_connectionString))
 		{
@@ -645,10 +656,13 @@ public override void Open()
 		}
 
 		LogMessages.ConnectionOpened(Log, this);
+		FbMetricsStore.ConnectionOpened(startedAtTicks, this._options.NormalizedConnectionString);
 	}
+
 	public override async Task OpenAsync(CancellationToken cancellationToken)
 	{
 		LogMessages.ConnectionOpening(Log, this);
+		var startedAtTicks = FbMetricsStore.ConnectionOpening();
 
 		if (string.IsNullOrEmpty(_connectionString))
 		{
@@ -741,6 +755,7 @@ public override async Task OpenAsync(CancellationToken cancellationToken)
 		}
 
 		LogMessages.ConnectionOpened(Log, this);
+		FbMetricsStore.ConnectionOpened(startedAtTicks, this._options.NormalizedConnectionString);
 	}
 
 	public override void Close()

src/FirebirdSql.Data.FirebirdClient/FirebirdClient/FbConnectionPoolManager.cs

@@ -167,6 +167,10 @@ static long GetTicks()
 			var ticks = Environment.TickCount;
 			return ticks + -(long)int.MinValue;
 		}
+
+		internal int AvailableCount => _available.Count;
+		internal int BusyCount => _busy.Count;
+		internal int MaxSize => _connectionString.MaxPoolSize;
 	}
 
 	int _disposed;
@@ -220,6 +224,12 @@ internal void ClearPool(ConnectionString connectionString)
 		}
 	}
 
+	internal Dictionary<string, (int idleCount, int busyCount, int maxSize)> GetMetrics() =>
+		_pools.ToDictionary(
+			kvp => kvp.Key,
+			kvp => (kvp.Value.AvailableCount, kvp.Value.BusyCount, kvp.Value.MaxSize)
+		);
+
 	public void Dispose()
 	{
 		if (Interlocked.Exchange(ref _disposed, 1) == 1)

src/FirebirdSql.Data.FirebirdClient/FirebirdClient/FbTransactionInfo.cs

@@ -33,6 +33,15 @@ public sealed class FbTransactionInfo
 
 	#region Methods
 
+	public long GetTransactionId()
+	{
+		return GetValue<long>(IscCodes.isc_info_tra_id);
+	}
+	public Task<long> GetTransactionIdAsync(CancellationToken cancellationToken = default)
+	{
+		return GetValueAsync<long>(IscCodes.isc_info_tra_id, cancellationToken);
+	}
+
 	public long GetTransactionSnapshotNumber()
 	{
 		return GetValue<long>(IscCodes.fb_info_tra_snapshot_number);

src/FirebirdSql.Data.FirebirdClient/FirebirdSql.Data.FirebirdClient.csproj

@@ -61,6 +61,7 @@
 	    <PrivateAssets>all</PrivateAssets>
 	    <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
 	  </PackageReference>
+	  <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="8.0.1" />
 	</ItemGroup>
 	<ItemGroup>
 	  <Compile Update="FirebirdClient\FbBatchCommand.cs" />