- Click the Windows "Start" button and then click "Control Panel." Click "System and Security." Click "Administrative Tools" in the list of utilities. Double-click the icon labeled "Data Sources (ODBC)." A list of DSNs display.
- Click the DSN you want to test.
- Click the "Test Connection" button.
SQL Server Management Studio Activity Monitor
Scroll down to the SPID of the process you would like to kill. Right click on that line and select 'Kill Process'. A popup window will open for you to confirm that you want to kill the process.sp_whoisactive is a comprehensive activity monitoring stored procedure that works for all versions of SQL Server from 2005 through 2017. You can find the most recent versions on the Downloads page.
Right-click the TrendDBTest. udl file and choose Properties to open the Data Link Properties dialog box. On the Data Link Properties, select the Provider tab. From the list of OLE DB Provider(s), select Microsoft OLE DB for SQL Server.
Background
- Create a file on the server called test. udl.
- Double-click the test.
- Click the Provider tab.
- Select Microsoft OLE DB Provider for SQL Server.
- Click Next.
- On the Connection tab, enter the connection information entered for the database connection:
- Type the SQL database credentials.
- Click Test Connection.
By default, SQL Server allows a maximum of 32767 concurrent connections which is the maximum number of users that can simultaneously log in to the SQL server instance.
To verify SQL connectivity using a UDL file:
- Create a text file on the ePO server.
- Rename it to test.
- Double-click the test.
- Click the Provider tab.
- Select SQL Server Native Client 11.0 .
- Click Next.
- On the Connection tab, enter the same information entered in the ePO core/config page for the database connection.
Testing a Connection Pool
- In the Administration Console, open the Resources component, open the JDBC component, select Connection Pools, and select the connection pool you want to test. Then select the Ping button in the top right corner of the page.
- Use the asadmin ping-connection-pool command.
Connection pooling is basically reusing the connection created with the database. Connection pooling reduces the number of times that new connections must be opened. When a request come to database, connection is established and when the connection is disposed the connection actually goes to the pool and kept alive.
When should connection leaks be detected? Every relational database offers a way to inspect the underlying connection status, so one can easily open a new SQL terminal and check if there are any connections dangling.
A connection pool is a set of idle, open, and reusable database connections maintained by the database server so that the connections can be reused when the database receives future requests for data, instead of exclusively opening a new connection.
ADO.NET uses a technique called connection pooling, which minimizes the cost of repeatedly opening and closing connections. Connection pooling reuses existing active connections with the same connection string instead of creating new connections when a request is made to the database.
Restart the SQL Server Instance, refresh it and again go to Properties > Connections and you will see 300 in "Maximum number of concurrent connections" scroll box.
In software engineering, a connection pool is a cache of database connections maintained so that the connections can be reused when future requests to the database are required. Connection pools are used to enhance the performance of executing commands on a database.
In addition, the default size of the connection pool is 100, but you may override this as well with connection string variables. Max Pool Size: The maximum number of connections allowed in the pool. The default value is 100. Min Pool Size: The minimum number of connections allowed in the pool.
Dapper will close the connection if it needed to open it. So if you're just doing 1 quick query - let Dapper handle it. Ofcourse, you can call multiple queries on single connection. But, connection should be closed (by calling Close() , Dispose() method or by enclosing it in using block) to avoid resource leak.
The most obvious way to determine whether a SQL Server database instance is having storage performance problems is to look in the SQL Server ERRORLOG file. A message about slow I/O in the ERRORLOG file is a good indicator that there's something wrong with the storage I/O subsystem.
On SQL Server, blocking occurs when one SPID holds a lock on a specific resource and a second SPID attempts to acquire a conflicting lock type on the same resource. The duration and transaction context of a query determine how long its locks are held and, thereby, their impact on other queries.
SELECT can block updates. A properly designed data model and query will only cause minimal blocking and not be an issue. The 'usual' WITH NOLOCK hint is almost always the wrong answer. The proper answer is to tune your query so it does not scan huge tables.
On SQL Server, blocking occurs when one SPID holds a lock on a specific resource and a second SPID attempts to acquire a conflicting lock type on the same resource. Typically, the time frame for which the first SPID locks the resource is very small.
Are they same? In blocking, one process is holding s resource that another process requires. SQL knows that once the blocking process finishes the resource will be available and so the blocked process will wait (until it times out), but it won't be killed. In a deadlock, there are 2 processes.
The sp_lock system stored procedure is a great tool for checking the amount of locking that occurs on your database system. It returns the number and types of locks that are being held by current active SQL Server sessions.
A block is a unit of code that provides execution and scoping boundaries for variable declarations and exception handling. PL/SQL allows you to create anonymous blocks (blocks of code that have no name) and named blocks, which may be packages, procedures, functions, triggers, or object types.
When the application is freezing , I notice there is a blocked by in SQL activity monitor and a head blocker. in my limited understanding , head blocker means a session is currently running and is locking a resource and that resource is also needed by another session.
