v1.27.2.0

- DB lista előállításának gyorsítása

v1.27.2.0
- DB lista előállításának gyorsítása
Schwirg László
1 parent eca09089
Showing 2 changed files with 178 additions and 168 deletions Show diff stats
Vrh.Log4Pro.MaintenanceConsole/Manager - SQLDataBaseManager.cs
Vrh.Log4Pro.MaintenanceConsole/Properties/AssemblyInfo.cs
@@ -38,6 +38,7 @@ namespace Vrh.Log4Pro.MaintenanceConsole.SQLDataBaseManagerNS
 		#region Execute
 		public static object Execute(object o1 = null, object o2 = null)
 		{
+			ServerConnectionPool.Init();
 			var args = (o1 as Menu.ExecutorParameter).Args;
 			var functionkey = CommandLine.GetCommandLineArgument(args, CLP.CMD_FUNCTION);
@@ -910,7 +911,7 @@ GO
 			menufct.ClearMenuItemList();
 			foreach (var def in defList)
 			{
-				var st = SQLDataBaseManagerCore.CollectDataBaseInfo(def);
+				var st = def.CollectInfo();
 				menufct.AddMenuItem(new Menu.Item(def.Xml_Key, null, null, new Menu.ExecutorParameter(pars: st)));
 			}
 			if (!silent) { menufct.DisplayItems(1); }
@@ -921,14 +922,15 @@ GO
 		private static object DisplayDataBaseInfo(object obj, int lineix)
 		{
 			SQLDataBase st = (obj as Menu.ExecutorParameter).Parameters as SQLDataBase;
+			//SQLDataBaseManagerCore.GetPhysicalFilesLocationAndSize(st.SQLCS,out string dbsizetext,out string dbpathtext);
 			if (lineix == 0)
 			{
 				ColorConsole.Write($"{st.Xml_Description}", ConsoleColor.Black, ConsoleColor.White);
-				var statuscolor = st.Status == SQLDataBaseManagerCore.SQLDBStatus.NoAccess ? ConsoleColor.Red:ConsoleColor.Green;
+				var statuscolor = st.Status == SQLDataBase.SQLDBStatus.NoAccess ? ConsoleColor.Red:ConsoleColor.Green;
 				ColorConsole.Write(st.Status.ToString(), statuscolor, bracket: "[]", prefix: " ", suffix: ". ");
 				ColorConsole.Write(st.DBName, statuscolor, bracket: "[]", prefix: "Database ", suffix: ". ");
 				ColorConsole.Write(st.DataSource, statuscolor, bracket: "[]", prefix: "from server ", suffix: ". ");
-				if (st.Status != SQLDataBaseManagerCore.SQLDBStatus.NoAccess) 
+				if (st.Status != SQLDataBase.SQLDBStatus.NoAccess) 
 				{
 				}
 				if (st.Xml_IsRemoteDB) { ColorConsole.Write("REMOTE", ConsoleColor.Cyan, bracket: "[]", prefix: "", suffix: ""); }
@@ -949,15 +951,13 @@ GO
 			}
 			else if (lineix == 3)
 			{
-				var phypath = (SQLDataBaseManagerCore.GetPhysicalFilesLocation(st.SQLCS))??"ERR";
-				ColorConsole.Write($"{phypath}", ConsoleColor.Yellow, prefix: "DB files physical location:", suffix: " ");
+				ColorConsole.Write($"{st.PhysicalFilesDirectoryPath}", ConsoleColor.Yellow, prefix: "DB files physical location:", suffix: " ");
 				ColorConsole.WriteLine(" ");
 				return " ";
 			}
 			else if (lineix == 4)
 			{
-				var dbsize = SQLDataBaseManagerCore.GetSize(st.SQLCS);
-				ColorConsole.Write(dbsize, ConsoleColor.Yellow, prefix: "DB size:", suffix: " ");
+				ColorConsole.Write(st.SizeString, ConsoleColor.Yellow, prefix: "DB size:", suffix: " ");
 				ColorConsole.WriteLine(" ");
 				return " ";
 			}
@@ -980,29 +980,6 @@ GO
 	#region class SQLDataBaseManager
 	public static class SQLDataBaseManagerCore
 	{
-		#region public CollectDataBaseInfo
-		public static SQLDataBase CollectDataBaseInfo(SQLDataBase sqld)
-		{
-			try
-			{
-				sqld.PhysicalFilesDirectoryPath = (GetPhysicalFilesLocation(sqld.SQLCS)) ?? "";
-				sqld.Status = string.IsNullOrWhiteSpace(sqld.PhysicalFilesDirectoryPath)? SQLDBStatus.NoAccess: SQLDBStatus.OK;
-				sqld.DBName = GetDBName(sqld.SQLCS);
-				sqld.DataSource = GetDataSource(sqld.SQLCS);
-				sqld.SizeString = GetSize(sqld.SQLCS);
-			}
-			catch 
-			{
-				sqld.Status = SQLDBStatus.NoAccess;
-				sqld.PhysicalFilesDirectoryPath = "";
-				sqld.DBName = GetDBName(sqld.SQLCS);
-				sqld.DataSource = GetDataSource(sqld.SQLCS);
-				sqld.SizeString = "";
-			}
-			return sqld;
-		}
-		#endregion public CollectDataBaseInfo
-
 		public static void RelocatePhysicalFiles(SQLDataBase sqld, string targetdirectory, string restoredbname)
 		{
 			var dbbackupfilepath = CreateBackup(sqld, false,null);
@@ -1055,7 +1032,7 @@ GO
 			Server sqlserver = null;
 			try
 			{
-				var sc = GetSqlConnection(sqlcs, "master");
+				var sc = ServerConnectionPool.GetSqlConnection(sqlcs, "master");
 				sqlserver = SQLServerConnect(sc);if (sqlserver == null) { return; }
 				var smoRestore = new Restore();
@@ -1261,9 +1238,8 @@ GO
 		}
 		public static void CreateUser(string sqldbconnectionString, string dbusername, string dbrolenamecommalist,string loginname)
 		{
-			using (SqlConnection connection = new SqlConnection(sqldbconnectionString))
+			using (SqlConnection connection = ServerConnectionPool.GetSqlConnection(sqldbconnectionString,open:true))
 			{
-				connection.Open();
 				// Create user
 				//USE [LearALM2]
 				//DROP USER[datareader]
@@ -1351,7 +1327,7 @@ GO
 			Server sqlserver = null;
 			try 
 			{
-				var sc = GetSqlConnection(sqldbconnectionString,null, grantoruser, grantoruserpsw);
+				var sc = ServerConnectionPool.GetSqlConnection(sqldbconnectionString,null, grantoruser, grantoruserpsw);
 				sqlserver = SQLServerConnect(sc); if (sqlserver == null) return;
 				Login login = new Login(sqlserver, name);
 				login.LoginType = logintype;
@@ -1406,7 +1382,7 @@ GO
 			Server sqlserver = null;
 			try
 			{
-				var sc = GetSqlConnection(cs, dbname:databasename, userid: userid, userpassword: password);
+				var sc = ServerConnectionPool.GetSqlConnection(cs, dbname:databasename, userid: userid, userpassword: password);
 				sqlserver = SQLServerConnect(sc); if (sqlserver == null) return false;
 				if (sqlserver.Databases.Contains(databasename))
 				{
@@ -1426,7 +1402,7 @@ GO
 			Dictionary<string, string> ReturnDict = new Dictionary<string, string>();
 			try
 			{
-				var sc = GetSqlConnection(cs, dbname: null, userid: userid, userpassword: password);
+				var sc = ServerConnectionPool.GetSqlConnection(cs, dbname: null, userid: userid, userpassword: password);
 				sqlserver = SQLServerConnect(sc); if (sqlserver == null) return null;
 				foreach (Database db in sqlserver.Databases) 
@@ -1489,18 +1465,9 @@ GO
 			var sqlcb = new SqlConnectionStringBuilder(cs);
 			return sqlcb.DataSource;
 		}
-		public enum SQLDBStatus { NoAccess, OK, }
-		public static SqlConnection GetSqlConnection(string sqlconnectionstring, string dbname = null, string userid = null, string userpassword = null)
-		{
-			var scb = new SqlConnectionStringBuilder(sqlconnectionstring);
-			if (!string.IsNullOrWhiteSpace(dbname)) { scb.InitialCatalog = dbname; }
-			if (!string.IsNullOrWhiteSpace(userid) && !string.IsNullOrWhiteSpace(userpassword)) { scb.UserID = userid; scb.Password = userpassword; }
-			else if (!string.IsNullOrWhiteSpace(userid) && string.IsNullOrWhiteSpace(userpassword)) { scb.UserID= userid; scb.IntegratedSecurity= true; }
-			return new SqlConnection(scb.ToString());
-		}
 		public static Server SQLServerConnect(string sqlconnectionstring,string dbname=null)
 		{
-			return SQLServerConnect(GetSqlConnection(sqlconnectionstring, dbname));
+			return SQLServerConnect(ServerConnectionPool.GetSqlConnection(sqlconnectionstring, dbname));
 		}
 		public static Server SQLServerConnect(SqlConnection sqlconnection)
 		{
@@ -1523,7 +1490,7 @@ GO
 		public static void ShrinkDB(string sqlconnectionstring, ShrinkMethod shrinkmethod,int freespacepercent)
 		{
-			using (var sqlc = new SqlConnection(sqlconnectionstring))
+			using (var sqlc =ServerConnectionPool.GetSqlConnection(sqlconnectionstring,open:false))
 			{
 				var sc = new ServerConnection(sqlc);
 				var srvr = new Server(sc);
@@ -1532,74 +1499,13 @@ GO
 			}
 		}
-		#region GetSize
-		/// <summary>
-		/// Visszadja a megadott adatbázis méretét
-		/// </summary>
-		/// <param name="sqlconnectionstring"></param>
-		/// <returns></returns>
-		public static string GetSize(string sqlconnectionstring)
-		{
-			try
-			{
-				using (var sqlc = new Microsoft.Data.SqlClient.SqlConnection(sqlconnectionstring))
-				{
-					var dbname = GetDBName(sqlconnectionstring);
-
-					var getsizecmd = new Microsoft.Data.SqlClient.SqlCommand("sp_spaceused", sqlc);
-					getsizecmd.CommandType = System.Data.CommandType.StoredProcedure;
-					sqlc.Open();
-					var reader = getsizecmd.ExecuteReader();
-
-					if (reader.HasRows)
-					{
-						while (reader.Read())
-						{
-							var dbn = reader["database_name"];
-							var dbs = reader["database_size"];
-							if (Convert.ToString(dbn) == dbname) { return Convert.ToString(dbs); };
-						}
-					}
-					sqlc.Close();
-				}
-				return "N/A";
-			}
-			catch { return "ERR"; }
-		}
-		#endregion GetSize
-
-		#region GetPhysicalFilesLocation
-		/// <summary>
-		/// Returns the physical path to the directory that holds the files of the database
-		/// </summary>
-		/// <param name="sqlconnectionstring"></param>
-		/// <returns>the path, or null, if any error occurs</returns>
-		public static string GetPhysicalFilesLocation(string sqlconnectionstring)
-		{
-			try
-			{
-				int commandtimeout = 5000;
-				string scripttext = "";
-				scripttext += " DECLARE @physicalpath varchar(1000) = NULL;";
-				scripttext += " SELECT @physicalpath = f.physical_name";
-				scripttext += " FROM sys.master_files as f inner join sys.databases as d on f.database_id = d.database_id";
-				scripttext += " where d.name = '{DATABASE}' and f.type_desc = 'ROWS';";
-				scripttext += " SELECT 1 AS RETURNCODE, @physicalpath AS RETURNMESSAGE;";
-				var vars = new Dictionary<string, string>();
-				vars.Add(nameof(DBSubstitutionName.DATABASE), GetDBName(sqlconnectionstring));
-				vars.Add(nameof(DBSubstitutionName.DATASOURCE), "");
-				var result = ExecuteSQLScript(sqlconnectionstring, scripttext, commandtimeout, vars);
-				if (result.ReturnValue != 0) { return Path.GetDirectoryName(result.ReturnMessage); } else { return null; };
-			}
-			catch { return null; }
-		}
-		#endregion GetPhysicalFilesLocation
 		#region DBSubstitution
 		public enum DBSubstitutionName
 		{
 			DBKEY,DATABASE,DATASOURCE,DBOTYPE,DBONAME,DBDATAGROUP,BACKUPTS,SHRINKOPTION,SHRINKFREESPACEPERCENT,
 		}
 		#endregion DBSubstitution
+
 		#region ExecuteSQLScript
 		/// <summary>
 		/// Egy SQL script végrehajtása (GO-val lezárt batch-eket tartalmazhat)
@@ -1621,66 +1527,55 @@ GO
 		/// </returns>
 		public static ReturnInfoJSON ExecuteSQLScript(string sqlconnectionstring, string sqltxt, int commandtimeout, Dictionary<string, string> vars)
 		{
-			using (var sqlc = new Microsoft.Data.SqlClient.SqlConnection(sqlconnectionstring))
-			{
-				sqltxt = VRH.Common.StringConstructor.ResolveConstructorR(vars, sqltxt, "{}@@");
-
-				sqlc.Open();
-				string SQLBatchTxt = ""; // ebben lesznek az sql script-en belüli batch-ek összerakva
-				int SQLBatchIndex = 0; // az aktuális batch indexe
-				int scriptlineindex = 0; // az aktuális script sor indexe
-				System.Data.DataSet DataSet = null; // ebben lesz az eredmény (az utolsó batch eredménye)
-				sqltxt += "\r\nGO";// ha esetleg nem lenne, odatesszük a végére az utolsó batch-et lezáró GO-t
-				foreach (var scriptline in sqltxt.Split(new char[] { '\r', '\n' }, StringSplitOptions.RemoveEmptyEntries))
+			using (var sqlc = ServerConnectionPool.GetSqlConnection(sqlconnectionstring,open:true)) { return ExecuteSQLScript(sqlc,sqltxt, commandtimeout, vars); }
+		}
+		public static ReturnInfoJSON ExecuteSQLScript(SqlConnection sqlconnection, string sqltxt, int commandtimeout, Dictionary<string, string> vars)
+		{
+			sqltxt = VRH.Common.StringConstructor.ResolveConstructorR(vars, sqltxt, "{}@@");
+
+			var connectionwasopen = true;
+			if (sqlconnection.State != System.Data.ConnectionState.Open) { ServerConnectionPool.Open(sqlconnection); connectionwasopen = false; }
+			string SQLBatchTxt = ""; // ebben lesznek az sql script-en belüli batch-ek összerakva
+			int SQLBatchIndex = 0; // az aktuális batch indexe
+			int scriptlineindex = 0; // az aktuális script sor indexe
+			System.Data.DataSet DataSet = null; // ebben lesz az eredmény (az utolsó batch eredménye)
+			sqltxt += "\r\nGO";// ha esetleg nem lenne, odatesszük a végére az utolsó batch-et lezáró GO-t
+			foreach (var scriptline in sqltxt.Split(new char[] { '\r', '\n' }, StringSplitOptions.RemoveEmptyEntries))
+			{
+				scriptlineindex += 1;
+				if (Regex.Match(scriptline, @"^GO$").Success)// a batch utolső sora
 				{
-					scriptlineindex += 1;
-					if (Regex.Match(scriptline, @"^GO$").Success)// a batch utolső sora
-					{
-						if (!string.IsNullOrWhiteSpace(SQLBatchTxt))
-						{
-							SQLBatchIndex += 1;
-							DataSet = ExecuteSQLScriptBatch(sqlc, SQLBatchTxt, commandtimeout);
-							SQLBatchTxt = "";
-						}
-					}
-					else if (!string.IsNullOrWhiteSpace(scriptline))
+					if (!string.IsNullOrWhiteSpace(SQLBatchTxt))
 					{
-						SQLBatchTxt += scriptline + "\r\n";
+						SQLBatchIndex += 1;
+						var sqlcommand = sqlconnection.CreateCommand();
+						sqlcommand.CommandText = SQLBatchTxt;
+						sqlcommand.CommandTimeout = commandtimeout;
+						var DataAdapter = new Microsoft.Data.SqlClient.SqlDataAdapter(sqlcommand);
+						DataSet = new System.Data.DataSet();
+						DataAdapter.Fill(DataSet);
+						SQLBatchTxt = "";
 					}
 				}
-
-				sqlc.Close();
-				try
+				else if (!string.IsNullOrWhiteSpace(scriptline))
 				{
-					var firstreturnedtable = DataSet.Tables[0];
-					var firstreturnedrow = firstreturnedtable.Rows[0];
-					var firstreturnedvalue = firstreturnedrow[0];
-					var secondreturnedvalue = firstreturnedrow[1];
-					var rv = Convert.ToInt32(firstreturnedvalue);
-					var rm = Convert.ToString(secondreturnedvalue);
-					return new ReturnInfoJSON() { ReturnValue = rv, ReturnMessage = rm, };
+					SQLBatchTxt += scriptline + "\r\n";
 				}
-				catch { }
 			}
-			return new ReturnInfoJSON() { ReturnValue = 0, ReturnMessage = null, };
-		}
-		/// <summary>
-		/// Egy SQL batch végrehajtása
-		/// </summary>
-		/// <param name="sqlc"></param>
-		/// <param name="sqlbatchtxt"></param>
-		/// <param name="commandtimeout"></param>
-		/// <returns></returns>
-		private static System.Data.DataSet ExecuteSQLScriptBatch(Microsoft.Data.SqlClient.SqlConnection sqlc, string sqlbatchtxt, int commandtimeout)
-		{
-			var sqlcommand = sqlc.CreateCommand();
-			sqlcommand.CommandText = sqlbatchtxt;
-			sqlcommand.CommandTimeout = commandtimeout;
-			var DataAdapter = new Microsoft.Data.SqlClient.SqlDataAdapter(sqlcommand);
-			var DataSet = new System.Data.DataSet();
-			DataAdapter.Fill(DataSet);
-			return DataSet;
+			if (!connectionwasopen) { sqlconnection.Close(); }
+			try
+			{
+				var firstreturnedtable = DataSet.Tables[0];
+				var firstreturnedrow = firstreturnedtable.Rows[0];
+				var firstreturnedvalue = firstreturnedrow[0];
+				var secondreturnedvalue = firstreturnedrow[1];
+				var rv = Convert.ToInt32(firstreturnedvalue);
+				var rm = Convert.ToString(secondreturnedvalue);
+				return new ReturnInfoJSON() { ReturnValue = rv, ReturnMessage = rm, };
+			}
+			catch { }
+			return new ReturnInfoJSON() { ReturnValue = 0, ReturnMessage = null, };
 		}
 		#endregion ExecuteSQLScript
 		#region ExecuteSQLStoredProcedure
@@ -1722,18 +1617,17 @@ GO
 		public static List<SPparameter> ExecuteSQLStoredProcedure(string sqlconnectionstring, string storedprocedurename, int commandtimeout, List<SPparameter> SPparameters)
 		{
-			using (var sqlc = new Microsoft.Data.SqlClient.SqlConnection(sqlconnectionstring))
-            {
+			using (var sqlc = ServerConnectionPool.GetSqlConnection(sqlconnectionstring,open:true))
+			{
 				var sqlcommand = sqlc.CreateCommand();
 				sqlcommand.Connection = sqlc;
 				sqlcommand.CommandText = storedprocedurename;
 				sqlcommand.CommandTimeout = commandtimeout;
 				sqlcommand.CommandType = System.Data.CommandType.StoredProcedure;
 				//var DataAdapter = new Microsoft.Data.SqlClient.SqlDataAdapter(sqlcommand);
-				sqlc.Open();
 				foreach (var p in SPparameters)
 				{
-					var sqlparameter = new Microsoft.Data.SqlClient.SqlParameter()
+					var sqlparameter = new SqlParameter()
 					{
 						ParameterName = p.Name,
 						SqlDbType = p.Type,
@@ -2077,7 +1971,7 @@ GO
 		public string DBName;
 		public string DataSource;
-		public SQLDataBaseManagerCore.SQLDBStatus Status;
+		public SQLDBStatus Status;
 		public string PhysicalFilesDirectoryPath;
 		public string SizeString;
 		public string SQLCS 
@@ -2085,6 +1979,81 @@ GO
 			get { return XmlProcessing.ConnectionStringStore.GetSQL(this.Xml_SQLConnectionString); }
 		}
 		#endregion fields
+		public enum SQLDBStatus { NoAccess, OK, }
+
+        #region CollectInfo
+        public SQLDataBase CollectInfo()
+		{
+			try
+			{
+				GetPhysicalFilesLocationAndSize(this.SQLCS, out this.SizeString, out this.PhysicalFilesDirectoryPath);
+				this.Status = this.PhysicalFilesDirectoryPath=="ERR" ? SQLDBStatus.NoAccess : SQLDBStatus.OK;
+				this.DBName = SQLDataBaseManagerCore.GetDBName(this.SQLCS);
+				this.DataSource = SQLDataBaseManagerCore.GetDataSource(this.SQLCS);
+			}
+			catch
+			{
+				this.Status = SQLDBStatus.NoAccess;
+				this.PhysicalFilesDirectoryPath = "";
+				this.DBName = SQLDataBaseManagerCore.GetDBName(this.SQLCS);
+				this.DataSource = SQLDataBaseManagerCore.GetDataSource(this.SQLCS);
+				this.SizeString = "";
+			}
+			return this;
+		}
+		#endregion CollectInfo
+
+		#region GetPhysicalFilesLocationAndSize
+		/// <summary>
+		/// Visszadja a megadott adatbázis méretét
+		/// </summary>
+		/// <param name="sqlconnectionstring"></param>
+		/// <returns></returns>
+		private void GetPhysicalFilesLocationAndSize(string sqlconnectionstring, out string dbsizetext, out string dbpathtext)
+		{
+			dbsizetext = null;
+			dbpathtext = null;
+			try
+			{
+				var sqlc = ServerConnectionPool.GetSqlConnection(sqlconnectionstring,open:true);
+				string dbname = SQLDataBaseManagerCore.GetDBName(sqlconnectionstring);
+				try
+				{
+					var getsizecmd = new SqlCommand("sp_spaceused", sqlc);
+					getsizecmd.CommandType = System.Data.CommandType.StoredProcedure;
+					var reader = getsizecmd.ExecuteReader();
+
+					if (reader.HasRows)
+					{
+						while (reader.Read()) { if (Convert.ToString(reader["database_name"]) == dbname) { dbsizetext = Convert.ToString(reader["database_size"]); break; }; }
+					}
+					dbsizetext = dbsizetext ?? "N/A";
+				}
+				catch { }
+
+				try
+				{
+					int commandtimeout = 5000;
+					string scripttext = "";
+					scripttext += " DECLARE @physicalpath varchar(1000) = NULL;";
+					scripttext += " SELECT @physicalpath = f.physical_name";
+					scripttext += " FROM sys.master_files AS f INNER JOIN sys.databases AS d ON f.database_id = d.database_id";
+					scripttext += " WHERE d.name = '{DATABASE}' AND f.type_desc = 'ROWS';";
+					scripttext += " SELECT 1 AS RETURNCODE, @physicalpath AS RETURNMESSAGE;";
+					var vars = new Dictionary<string, string>();
+					vars.Add(nameof(SQLDataBaseManagerCore.DBSubstitutionName.DATABASE), dbname);
+					vars.Add(nameof(SQLDataBaseManagerCore.DBSubstitutionName.DATASOURCE), "");
+					var result = SQLDataBaseManagerCore.ExecuteSQLScript(sqlc, scripttext, commandtimeout, vars);
+					if (result.ReturnValue != 0) { dbpathtext = Path.GetDirectoryName(result.ReturnMessage); }
+				}
+				catch { }
+				sqlc.Close();
+			}
+			catch { }
+			dbsizetext = dbsizetext ?? "ERR";
+			dbpathtext = dbpathtext ?? "ERR";
+		}
+		#endregion GetPhysicalFilesLocationAndSize
 		#region basic constructor
 		public SQLDataBase() { }
@@ -2265,4 +2234,45 @@ GO
 		#endregion SQLData class
 	}
 	#endregion SQLDataBase class
+
+	public static class ServerConnectionPool
+    {
+		private static List<string> InaccessibleConnectionList = new List<string>();
+		public static SqlConnection GetSqlConnection(string sqlconnectionstring, string dbname = null, string userid = null, string userpassword = null,bool open=false)
+		{
+			var scb = new SqlConnectionStringBuilder(sqlconnectionstring);
+			if (!string.IsNullOrWhiteSpace(dbname)) { scb.InitialCatalog = dbname; }
+			if (!string.IsNullOrWhiteSpace(userid) && !string.IsNullOrWhiteSpace(userpassword)) { scb.UserID = userid; scb.Password = userpassword; }
+			else if (!string.IsNullOrWhiteSpace(userid) && string.IsNullOrWhiteSpace(userpassword)) { scb.UserID = userid; scb.IntegratedSecurity = true; }
+			var sqlc = new SqlConnection(scb.ToString());
+			if (open) Open(sqlc);
+			return sqlc;
+		}
+		public static void Open(SqlConnection sqlc) 
+		{
+			if (IsMasterInacessible(sqlc) || IsInacessible(sqlc))
+			{ 
+				throw new Exception($"DB {sqlc.Database} on server {sqlc.DataSource} is inaccessible!"); 
+			}
+			try { sqlc.Open(); } 
+			catch (Exception ex) 
+			{
+				MarkMasterInacessible(sqlc);
+				MarkInacessible(sqlc);
+				throw ex; 
+			}
+		}
+		private static bool IsMasterDBConnected(SqlConnection sqlc) 
+		{
+			try { (new SqlConnection((new SqlConnectionStringBuilder(sqlc.ConnectionString) { InitialCatalog = "master" }).ToString())).Open(); return true; }
+			catch { return false; }
+		}
+		private static string MasterDBId(SqlConnection sqlc) { return sqlc.DataSource + "#master"; }
+		private static string DBId(SqlConnection sqlc) { return sqlc.DataSource + "#" + sqlc.Database; }
+		private static bool IsInacessible(SqlConnection sqlc) { return InaccessibleConnectionList.Contains(DBId(sqlc)); }
+		private static bool IsMasterInacessible(SqlConnection sqlc) { return InaccessibleConnectionList.Contains(MasterDBId(sqlc)); }
+		private static void MarkInacessible(SqlConnection sqlc) { if (!IsInacessible(sqlc)) { InaccessibleConnectionList.Add(DBId(sqlc)); }}
+		private static void MarkMasterInacessible(SqlConnection sqlc) { if (!IsMasterInacessible(sqlc)) { InaccessibleConnectionList.Add(MasterDBId(sqlc)); } }
+		public static void Init() { InaccessibleConnectionList.Clear(); }
+	}
 }
@@ -32,5 +32,5 @@ using System.Runtime.InteropServices;
 // You can specify all the values or you can default the Build and Revision Numbers
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("1.27.1.0")]
-[assembly: AssemblyFileVersion("1.27.1.0")]
+[assembly: AssemblyVersion("1.27.2.0")]
+[assembly: AssemblyFileVersion("1.27.2.0")]