Hello everyone,

I am hosting a WCF service in IIS using basicHttpBinding using streaming mode. The WCF web services queries back end SQL Server 2008 by using ADO.Net and return a DataTable to client side of WCF service.

My understanding of WCF streaming mode are,

1. WCF streaming mode should use only constant number of memory at both client and server side;
2. WCF streaming mode should be able to transfer any number of data between client and server.

Are my understandings correct?

If yes, my following sample break these two rules, I observe two violations,

1. I find my following sample continues to eat memory (from performance tab of task manager, memory usage increases). I run both client and server on the same machine. So, WCF streaming mode does not use constant amount of memory?

2. when transfer 10M rows of a DataTable, there is exception posted below. But transfer 1M rows are fine. So, WCF streaming mode cannot transfer any number of data?

Any ideas what is wrong?


Exception message:

Code:
  An error occurred while receiving the
  HTTP response to
  http://labmachine1/service.svc. This
  could be due to the service endpoint
  binding not using the HTTP protocol.
  This could also be due to an HTTP
  request context being aborted by the
  server (possibly due to the service
  shutting down). See server logs for
  more details.
 
 {"The underlying connection was closed: An unexpected error occurred
  on a receive."}
Here is my whole source code for server side, for the server I host in web.config, no change for default values. Since I host in IIS, I am using basicHttpBinding.


Code:
    public class StudentManagement : IStudentManagement
    {
        public DataTable Poll(int Id)
        {
            return MakeParentTable();
        }

        private DataTable MakeParentTable()
        {
            // Create a new DataTable.
            System.Data.DataTable table = new DataTable("ParentTable");
            // Declare variables for DataColumn and DataRow objects.
            DataColumn column;
            DataRow row;

            // Create new DataColumn, set DataType, 
            // ColumnName and add to DataTable.    
            column = new DataColumn();
            column.DataType = System.Type.GetType("System.Int32");
            column.ColumnName = "id";
            column.ReadOnly = true;
            column.Unique = true;
            // Add the Column to the DataColumnCollection.
            table.Columns.Add(column);

            // Create second column.
            column = new DataColumn();
            column.DataType = System.Type.GetType("System.String");
            column.ColumnName = "ParentItem";
            column.AutoIncrement = false;
            column.Caption = "ParentItem";
            column.ReadOnly = false;
            column.Unique = false;
            // Add the column to the table.
            table.Columns.Add(column);

            // Make the ID column the primary key column.
            DataColumn[] PrimaryKeyColumns = new DataColumn[1];
            PrimaryKeyColumns[0] = table.Columns["id"];
            table.PrimaryKey = PrimaryKeyColumns;

            // Create three new DataRow objects and add 
            // them to the DataTable
            for (int i = 0; i <= 10000000; i++)
            {
                row = table.NewRow();
                row["id"] = i;
                row["ParentItem"] = "ParentItem " + i;
                table.Rows.Add(row);
            }

            return table;
        }
    }
Client side code:

Code:
    static void Main(string[] args)
    {
        StudentIdentifier identifier = new StudentIdentifier();
        identifier.Id = 100;
        StudentManagementClient client = new StudentManagementClient();
    
        DataTable student = client.Poll(identifier);
    
        Console.WriteLine(student.Rows.Count);
    }
Streaming mode configuration for client side app.config,

Code:
        <basicHttpBinding>
          <binding name="BasicHttpBinding_IStudentManagement" closeTimeout="00:01:00"
            openTimeout="00:20:00" receiveTimeout="01:00:00" sendTimeout="01:00:00"
            allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard"
            maxBufferSize="1500000000" maxBufferPoolSize="1500000000" maxReceivedMessageSize="1500000000"
            messageEncoding="Mtom" textEncoding="utf-8" transferMode="Streamed"
            useDefaultWebProxy="true">
            <readerQuotas maxDepth="1500000000" maxStringContentLength="1500000000"
              maxArrayLength="1500000000" maxBytesPerRead="1500000000" maxNameTableCharCount="1500000000" />
            <security mode="None">
              <transport clientCredentialType="None" proxyCredentialType="None"
                realm="" />
              <message clientCredentialType="UserName" algorithmSuite="Default" />
            </security>
          </binding>
        </basicHttpBinding>
Server side web.config for streaming mode,

Code:
      <basicHttpBinding>
        <binding name="BasicHttpBinding_IStudentManagement" closeTimeout="00:01:00"
            openTimeout="00:20:00" receiveTimeout="01:00:00" sendTimeout="01:00:00"
            allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard"
            maxBufferSize="1000000000" maxBufferPoolSize="1000000000" maxReceivedMessageSize="1000000000"
            messageEncoding="Mtom" textEncoding="utf-8" transferMode="Streamed"
            useDefaultWebProxy="true">
          <readerQuotas maxDepth="32" maxStringContentLength="1000000000" maxArrayLength="1000000000"
              maxBytesPerRead="4096" maxNameTableCharCount="16384" />
          <security mode="None">
            <transport clientCredentialType="None" proxyCredentialType="None"
                realm="" />
            <message clientCredentialType="UserName" algorithmSuite="Default" />
          </security>
        </binding>
      </basicHttpBinding>
thanks in advance,
George