Sql server client statistics code#

If I execute the command the first time but only open and close/dispose the connection the 2-10th times (i.e. A couple of other nit-picky observations: So profiler reports a pooled logout/login (on a pooled connection) when we don't have a pooled connection (according to profiler)В that can beВ logged out. Each subsequent time through, when the command is issued (remember, RESETCONNECTION is a bit on the first message in the batch, not part of the login message), Profiler reports the following three messages, followed by the SQL command that you actually execute: The first time through, on the initial connnection to the server, Profiler reports a Non-pooled connection. NET 4.0 client and SQL Server 2012 server:Д¬reate a new SqlConnection and SqlCommandД¬all close (and dispose for good measure) on the connection So I set up a short test program that does the following 10 times (remember, connection pooling is on by default).This was run on. BTW, there is analogous information in XEvents. But the client implements the pools, recycles the connections, and sends the reset bit for the server to act on.ДЇolks that think SQL Server can distinguish which connections use pooling in the clientВ usually point to a the fact that the AuditLogin/AuditLogoff events in profiler indicate in the Event Subclass field whether or not a connection is pooled. If you consider sp_reset_connection as part of 'connection pooling' (it's certainly essential for it to work properly), you can consider (maybe, during an argument)В that part of 'connection pooling' to be implemented in the server.

Running sp_reset_connection is a lot faster than redoing the entire login protocol exchange, that's the time-savings of connection pooling. This causes SQL Server to run the system stored procedure sp_reset_connection on the server's session. When the client reuses the connection again, instead of logging on, the first batch of sQL executed causes a RESETCONNECTION bit to be set on the first TDS packet to the sent (there is also a related RESETCONNECTIONSKIPTRANSACTION bit, but that's not relevent for this discussion). Instead, you can think of the connection being 'active' on the server, but not in use in the client's pool.

Sql server client statistics code#

When the client-side code requests a connection close (or even connection dispose), the connection is not removed from the pool, log out does not occur on the server. When connection pooling opens a connection for the first time, it actually goes through the TDS message exchange to log in to the server. In ADO.NET, connection pooling is on by default, unless you turn if off in the connection string. Connection pooling is implemented on a per-client, per-appdomain basis in ADO.NET, and all the connection string parameters must match for a pooled connection to be reused. NET reflector and trace it using the client-side trace. I'll refer to ADO.NET here (because it has some nice, client-side, perfmon counters) but this is true of OLE DB, ODBC, and JDBC as well, although ADO.NET uses different code. Here's what's happening.Д¬onnection pooling is implemented almost entirely in the client stack. 'Can SQL Server distinguish a which connections use connection pooling?' The answer depends on how you ask the question, and I've tried to ask it in such a way that it's as ambiguous as it usually sounds. A variation of thisВ question came up a few weeks ago on a mail list that I subscribe to and it seems to come up a lot.