timeout period elapsed. all pooled connections wer

Question

After some time the following error page is shown.

What can I do to prevent this?

I have large numbers of users and the app uses Oracle 11g. Please suggest me pool size so can be extended default max pool size is 100.

I have checked all connections properly closed. I am using OracleDataReader and Datatable in my application Method that i am using is as under:

 public OracleDataReader BidNoIncr()
    {
        OracleConnection objOracleConnection = new OracleConnection(objDBClass.GetConnSring());
        OracleDataReader objDataReader;
        string strQuery = "Select max(BID_NO)+1 as SNumber from HH_BIDS";
        OracleCommand objOracleCommand = new OracleCommand(strQuery, objOracleConnection);
           objOracleConnection.Open();
           objDataReader = objOracleCommand.ExecuteReader(System.Data.CommandBehavior.CloseConnection);       
            return objDataReader;

Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidOperationException: Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached.

Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[InvalidOperationException: Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached.]
System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) +309609
System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) +125
System.Data.OracleClient.OracleConnection.Open() +43
DbClass.GetConnSring() +58 DBViewRec.ViewSalvageItems() +53
viewsalvageitems.ShowRecords() +44
viewsalvageitems.Page_Load(Object sender, EventArgs e) +5
System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35 System.Web.UI.Control.OnLoad(EventArgs e) +91
System.Web.UI.Control.LoadRecursive() +74
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2207

Answer 1

In general, this error may occur in the following situations:

1) You have a very large number of users using your database in the same time and you run out of free connections. Possible solutions: increase number of allowed connections on your server and/or (if your system is a webserver) increase the pool size specified in database connection string.

2) Your system has poor database logic design and/or connection leaks like when connection open isn't closed properly later. Solution for this will be auditing your code for such connection leaks and fixing them by properly closing connections all the time.