MySQL Connection too slow

Question

Please anyone with expirience in applets accessing MySQL Server!
I made a test with a loop code executing queries and got the following conclusion:
In media a query takes more than 2 seconds. I used PrepareStatement for better performance but it doesn�t make it better. I�ve heart about persistent connection. It�s realy faster? You know anything I could do for better performance? Obs.: When I ping my server the time answer is 200 ms. I�m from Brazil. But I think it sholdn�t make the mysql too slow as it is. Please help me.....
I�m very thank for ur help..
My java code:
     public void ConectaBD()
          try
               Class.forName("com.mysql.jdbc.Driver").newInstance();
               //Class.forName("org.gjt.mm.mysql.Driver").newInstance();
          catch(Exception e)
               System.out.println("Error: " + e);
          try
               con = DriverManager.getConnection("jdbc:mysql://labinfor.com.br/labinfor_codvirtual?user=labinfor_cliente&password=800091");
          catch(SQLException e)
               System.out.println("Error: " + e );
               e.printStackTrace();
public void Logon()
               java.util.Date start = new java.util.Date();
               long startTime = start.getTime();
if (ValidaCPF(TFCPF.getText()))
queryLogon = "SELECT Nome FROM clientes WHERE CPF='" + TFCPF.getText().trim() + "' AND senha='" + TFSenha.getText() + "'";
int indCon=0;
Timer t = new Timer(1000, this);
t.start();
while(indCon<100)
     Conecta();
     try
               stmt[indStmt] = con.createStatement();
     rsLogon = stmt[indStmt].executeQuery(queryLogon);
     Achou = "false";
     while (rsLogon.next())     
     Achou = "true";
     StrNome = rsLogon.getString(1);
     LValidaCPF.setText("Bem-vindo " + StrNome);
     TFCPF.disable();
     TFSenha.disable();
     BLogon.setLabel("Logoff");
                                   System.out.println("delay["+indCon+"]= "+System.currentTimeMillis());
     if (Achou == "false")
     LValidaCPF.setText("CPF ou senha incorreto");
     Desconecta();
     catch(Exception e)
     System.out.println("Error: " + e);
     indCon+=1;
}

Answer 1

Connection times of 1 to 5 seconds are normal. Pool your connections.
To understand why:
First, setting up a TCP/IP connection takes roughly 50% longer than a ping; a ping is one packet to the server and one packet back, a TCP/IP handshake to create a connection is one packet to the server, one back, and another to the server. Then you have a required brief wait before the connection is considered complete; we'll ignore the wait and call it .3 seconds for the TCP/IP handshake.
Second, the database has to go through the login process. Just sending the login request and response is yet another packet round trip; in your case, that's another .2 seconds in just network time alone. With MySQL, the login involves checking the security of the connection and the user; it often requires a reverse DNS lookup on the IP address of the client. Probably 4 or 5 tables have to be queried and a user environment is created within the server. The server work for the login might take .75 seconds, at a guess. Adding the network time makes this step .95 seconds or so.
Third, there's the time it takes to do the query itself; another network round trip; .2 second network round trip, plus maybe .1 second to run the query on the database, for a total of .3 seconds.
Fourth, there's the time it takes to tear down the TCP/IP connection on connection close. That involves 4 packets, 2 round-trips, so add another .4 seconds.
Adding it all up, you get .3 + .95 + .3 + .4 = 1.95 seconds, of which .3 is your SQL query (network and DB time), .9 is network time for TCP/IP connection and login request, and .75 is DB time for the login.