Currently all connections getting "Timeout expired"

I have an application which connects to SQL Server. Currently I am getting, Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached. When I ran, SELECT DB_NAME(dbid) as DBName, COUNT(dbid) as NumberOfConnections, loginame as LoginName FROM sys.sysprocesses WHERE DB_NAME(dbid) ='MyDb' GROUP BY dbid, loginame DBName NumberOfConnections LoginName MyDb 10 sa MyDb 109 MyUser The status of all process is sleeping and cms is AWAITING COMMAND Here is my code, private async Task ExecuteAsync(ExecutionType executionType, CommandType commandType, string commandText, IsolationLevel isolationLevel, SqlParameter[] parameters, Func callback = null) { var stopwatch = new Stopwatch(); stopwatch.Start(); using (var connection = new SqlConnection(_settings.DatabaseConnectionString)) { using (var command = new SqlCommand(commandText, connection) {CommandType = commandType}) { command.Parameters.AddRange(parameters); await connection.OpenAsync().ConfigureAwait(false); command.CommandTimeout = _settings.CommandTimeout; var transaction = connection.BeginTransaction(isolationLevel); command.Transaction = transaction; try { object result; switch (executionType) { case ExecutionType.Reader: var reader = await command.ExecuteReaderAsync().ConfigureAwait(false); using (reader) { var list = new List(); while (reader.Read()) { if (callback != null) { var item = callback(reader); if (item != null) { list.Add(item); } } } result = list; } break; case ExecutionType.NonQuery: result = await command.ExecuteNonQueryAsync().ConfigureAwait(false); break; default: result = await command.ExecuteScalarAsync().ConfigureAwait(false); break; } transaction.Commit(); stopwatch.Stop(); var elapsed = stopwatch.Elapsed; if (elapsed.Seconds > 2) { _logger.Log(string.Format("{0} took {1} time", command.CommandText, elapsed));// only log if it tooks more than 2 seconds } return result; } catch (Exception exception) { _logger.Log(exception); transaction.Rollback(); throw; } } } }