Question

I have a rather simple web-service which exposes data from sql server. It will be used to synchronize data between 2 different databases (SQL Server and Lotus Notes). We’re in the stage of testing the web-service and poll it with 20 req./min., the first 2 minutes it goes OK, but after the second, we’re getting an exception, obviously the connection (to the database) can’t be opened(timeout).

Do you have any tips/recommendations on what to do or where to look at? The web-service has been programmed using C#/.NET, the connection to the db is opened during construction of (web-service) object and closed when the object is disposed.

I’ve considered using global.asax to ‘share’ the connection but after some googling I found out most people find that a bad idea and I’m looking for a different solution.

ps. the service is pooled in a synchronous way, no 2 requests exist at the same time

-edit- (after first 2 anwsers about pooling) This is current code:

public class DataService : System.Web.Services.WebService {     private SqlConnection conn = new SqlConnection('Data Source=ip;database=database;uid=user;pwd=secret;');     public DataService ()      {             try             {                 conn.Open();              }             catch (Exception dbconn)             {                 throw new SoapException('Couldn't open connection to database:' + dbconn.Message + ' More info at: ' + dbconn.HelpLink, errorCode);             }             //Uncomment the following line if using designed components              //InitializeComponent();      }     ~DataService()     {          conn.Close();     }     [WebMethod(Description='Gets all Person changes(from last week)')]     public Person[] GetPerson()     {              Person[] Personen = null;             SqlCommand sqlcmd = conn.CreateCommand();              sqlcmd.CommandText = 'SELECT * FROM Person';             SqlDataReader Rows = sqlcmd.ExecuteReader();             while (Rows.Read())             {                     //doSomething             }              Rows.Close();             return Personen;     } 

}

Answer 1

Sounds like you’ve exhausted the connection pool — best option is to wrap you SQL calls with using blocks, loosely thus:

using( SqlConnection con = new SqlConnection( 'MyConnectionString' ) ) {     con.Open();      using( SqlCommand cmd = new SqlCommand( 'MyStoredProcedure', con ) )     {         // Do stuff with the Command     } } 

This will allow you to serve concurrently the same number of requests as the size of your connection pool.

So, the code after your edit becomes:

public class DataService : System.Web.Services.WebService {     [WebMethod(Description='Gets all Person changes(from last week)')]     public Person[] GetPerson()     {          Person[] Personen = null;          using( SqlConnection conn = new SqlConnection('Data Source=ip;database=database;uid=user;pwd=secret;') )         {             using( SqlCommand sqlcmd = conn.CreateCommand() )             {                 sqlcmd.CommandText = 'SELECT * FROM Person';                 SqlDataReader Rows = sqlcmd.ExecuteReader( CommandBehavior.CloseConnection ); // This will close the DB connection ASAP                 while (Rows.Read())                 {                     //doSomething                 }                  Rows.Close();             }         }          return Personen;     } }