I'm profiling a ASP.NET web application. I believe it is very database connection intensive (excessive use of the ADO.NET connection pool). How to I tell w/out debugging how many times it is going to the pool and on average how many connections are available in the pool? Are there counters that will give me this info in PerfMon or some other tool?
Asp – How Do I Profile the ADO.NET Connection Pool
ado.netasp.netconnection-pooling
Related Solutions
eval()
is not necessary. This will work fine:
var date = new Date(parseInt(jsonDate.substr(6)));
The substr()
function takes out the /Date(
part, and the parseInt()
function gets the integer and ignores the )/
at the end. The resulting number is passed into the Date
constructor.
I have intentionally left out the radix (the 2nd argument to parseInt
); see my comment below.
Also, I completely agree with Rory's comment: ISO-8601 dates are preferred over this old format - so this format generally shouldn't be used for new development.
For ISO-8601 formatted JSON dates, just pass the string into the Date
constructor:
var date = new Date(jsonDate); //no ugly parsing needed; full timezone support
In most cases connection pooling problems are related to connection leaks. Your application probably doesn't close its database connections correctly and consistently. When you leave connections open, they remain blocked until the .NET garbage collector closes them for you by calling their Finalize()
method.
You want to make sure that you are really closing the connection. For example the following code will cause a connection leak, if the code between .Open
and Close
throws an exception:
var connection = new SqlConnection(connectionString);
connection.Open();
// some code
connection.Close();
The correct way would be this:
var connection = new SqlConnection(ConnectionString);
try
{
connection.Open();
someCall (connection);
}
finally
{
connection.Close();
}
or
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
someCall(connection);
}
When your function returns a connection from a class method make sure you cache it locally and call its Close
method. You'll leak a connection using this code for example:
var command = new OleDbCommand(someUpdateQuery, getConnection());
result = command.ExecuteNonQuery();
connection().Close();
The connection returned from the first call to getConnection()
is not being closed. Instead of closing your connection, this line creates a new one and tries to close it.
If you use SqlDataReader
or a OleDbDataReader
, close them. Even though closing the connection itself seems to do the trick, put in the extra effort to close your data reader objects explicitly when you use them.
This article "Why Does a Connection Pool Overflow?" from MSDN/SQL Magazine explains a lot of details and suggests some debugging strategies:
- Run
sp_who
orsp_who2
. These system stored procedures return information from thesysprocesses
system table that shows the status of and information about all working processes. Generally, you'll see one server process ID (SPID) per connection. If you named your connection by using the Application Name argument in the connection string, your working connections will be easy to find. - Use SQL Server Profiler with the SQLProfiler
TSQL_Replay
template to trace open connections. If you're familiar with Profiler, this method is easier than polling by using sp_who. - Use the Performance Monitor to monitor the pools and connections. I discuss this method in a moment.
- Monitor performance counters in code. You can monitor the health of your connection pool and the number of established connections by using routines to extract the counters or by using the new .NET PerformanceCounter controls.
Best Answer
Look at ADO.NET performance counters:
http://msdn.microsoft.com/en-us/library/ms254503.aspx