Website's performance issue - asp.net

Question

I have an Asp.Net website with one web page whose sole purpose is receiving data in the form of a query string then separate it as required and store this data to the database.
This data comes from several Vehicle Tracking Systems. Each vehicle sends a string of data as query string every 30 seconds.
I have written the code in my webpage in such a way that as the webpage is accessed, in the page load, I read the query string and do the insert operation into the database. Something like this-
protected void Page_Load(object sender, EventArgs e)
{
con.Open();
string input = Request.QueryString["vinput"];
var m = Regex.Match(input, #"~(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#");
if (m.Success)
{
string[] vals = new string[20];
int j = 1;
for (int i = 0; i < 20; i++)
{
vals[i] = m.Groups[j].Value;
j++;
}
cmd.CommandText = "insert into tracking (vehicle_no,hardware_id,lat,lng,speed,direction,an0,an1,an2,an3,di0,di1,di2,di3,do0,do1,do2,do3,tdate,ttime) values('" + vals[0] + "','" + vals[1] + "','" + vals[2] + "','" + vals[3] + "','" + vals[4] + "','" + vals[5] + "','" + vals[6] + "','" + vals[7] + "','" + vals[8] + "','" + vals[9] + "','" + vals[10] + "','" + vals[11] + "','" + vals[12] + "','" + vals[13] + "','" + vals[14] + "','" + vals[15] + "','" + vals[16] + "','" + vals[17] + "','" + vals[18] + "','" + vals[19] + "')";
cmd.Connection = con;
cmd.ExecuteNonQuery();
}
}
I created a simulator app for testing this site in place of vehicle tracking systems. This site works fine when there is data coming from one to three simulator instances, but fails to save data to database when more than 3 simulator instances send data simultaneously(Approximately).
For example, I am sending 5 records, each one at a time from the simulator and 6 such simulator instances sending data to the page. At the end in the database I see only 15 records inserted instead of 30 records. By the way this website runs in IIS 5.1.
How do I deal with this issue? Suggestions please.
UPDATE: Finally found the issue. After a lot of googling found this link and this. Its with the server, since the request limit is only 3 for basic/starter in windows xp IIS.

Answer 1

No point in using a Page when you can use something lighter weight like a handler. You can switch a few things around, but this is not a heavy operation. Here's a pretty optimal way to do it with one exception and that would be to make a stored procedure rather than generating an insert statement from a string:
public class htest : System.Web.IHttpHandler
{
public bool IsReusable
{
get { return false; }
}
public void ProcessRequest(System.Web.HttpContext context)
{
System.Web.HttpRequest Request = context.Request;
Match m = Regex.Match(Request.QueryString["vinput"], #"~(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#(.+)#");
if (m.Success)
{
using (System.Data.SqlClient.SqlConnection con = new System.Data.SqlClient.SqlConnection())
{
try
{
con.Open();
System.Data.SqlClient.SqlCommand cmd = new System.Data.SqlClient.SqlCommand("command", con);
string[] vals = new string[20];
int j = 1;
for (int i = 0; i < 20; i++)
{
vals[i] = m.Groups[j].Value;
j++;
}
cmd.CommandText = "insert into tracking (vehicle_no,hardware_id,lat,lng,speed,direction,an0,an1,an2,an3,di0,di1,di2,di3,do0,do1,do2,do3,tdate,ttime) values('" + vals[0] + "','" + vals[1] + "','" + vals[2] + "','" + vals[3] + "','" + vals[4] + "','" + vals[5] + "','" + vals[6] + "','" + vals[7] + "','" + vals[8] + "','" + vals[9] + "','" + vals[10] + "','" + vals[11] + "','" + vals[12] + "','" + vals[13] + "','" + vals[14] + "','" + vals[15] + "','" + vals[16] + "','" + vals[17] + "','" + vals[18] + "','" + vals[19] + "')";
cmd.Connection = con;
cmd.ExecuteNonQuery();
}
catch
{
//At least do some type of logging in this event.
}
finally
{
con.Close();
}
}
}
context.Response.ContentType = "text/plain";
context.Response.Write("Success");
}
}
Obviously you can use some boolean values to determine what you write back to the client at the end.

Answer 2

few suggestions..
You are opening connection. please close it at bottom as well. Dispose cmd object as well.
Put your INSERT Ststement into a SQL Transcation
USe try and Catch (USe the Catch clause to store error messages into Database , ex.message returns error detail.)