WEB service not responding multiple request for saving database transection

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C#

XML

service

web

Hello Every One,

I have one webservice for sync Local to server,
I have local 10 client or more want to send all local database transaction on server at a time.
i am using following code

for (int i = 0; i < ds.Tables.Count; i++)
               {
                   if (ds.Tables[i].TableName != "Table")
                   {
                       if (ds.Tables[i].Rows.Count > 0)
                       {
                           string tblName = string.Empty;
                           tblName = ds.Tables[i].TableName;
                           SqlDataAdapter oOrderDetailsDataAdapter = new SqlDataAdapter(new SqlCommand("SELECT * FROM " + tblName, sqlConn));
                           SqlCommandBuilder oOrderDetailsCmdBuilder = new SqlCommandBuilder(oOrderDetailsDataAdapter);
                           oOrderDetailsDataAdapter.FillSchema(ds, SchemaType.Source);
                           count = oOrderDetailsDataAdapter.Update(ds, tblName);
                         
                       }
                   }
                   if (ds.Tables.Contains("Table"))
                       ds.Tables.Remove("Table");
                   if (count != 0)
                       count = 1;
               }

for Bulk transaction entry save in database as per table wise.
web service is integrate with C# windows application. and used XML FOR data transmission For local to server.(On Local Made XML file for day wise transaction.and this XML file pass to Web service for DATA Posting On server )
when a single request is hit to web service it will work.But when run my exe On multiple client system it will stuck, Not posted any transaction on server database.
and task is running for longer time.
Please Help Me how to Post data at time On server.

Thanks In Advance...!!!

What I have tried:

I tried to send data shorter amount of multiple file.
but it not work..
help mi to send data at a time from Multiple client PC.
And How it will Do.
Thanks In Advance.