Question

I have and asp.net mvc 3 web site. When running it on local VS web server or IIS express it`s ok. But when running it on IIS (IIS 7.5 Windows 2008 R2) it seems like memory leak as memory usage is growing all the time. Any ideas?

One more update: there`s such a code in the app:

SqlConnection conn = new SqlConnection { //creating connection here };
conn.Open();
SqlCommand command = conn.CreateCommand();

try
{
    var reader = command.ExecuteReader();
    while (reader.Read())
    {
       //read the data
    }
}
finally
{
   conn.Close();
}

Maybe there should be something like reader.Dispose? Can it be the cause of memory leak?

---

UPDATE: for some reason gc.Collect fixes the issue. But it`s not hte way out as calling gc.collect all the way is a bad idea.

Answer 1

well best practice here would be to use brackets, this is a great feature of c#. when you use the “using” keyword with a bracket, it would dispose the used object automatically, when running out of the bracket scope. here’s an example;

// SqlConnection implements IDisposable, will be disposed after bracket is closed
using(SqlConnection conn = new SqlConnection())
{
      conn.Open();
      // SqlCommand implements IDisposable, will be disposed after bracket is closed
      using(SqlCommand command = conn.CreateCommand())
      {
         // DataReader implements IDisposable, will be disposed after bracket is closed
         using(var reader = command.ExecuteReader())
         {
            while (reader.Read())
            { 
              // read here.
            }
         }
      }
}

Here’s also the microsoft link that says “The connection is automatically closed at the end of the using block.” http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection.close%28v=VS.85%29.aspx

I hope it helps.