MySQL remote connection [not as usual]

Question

I\'m not getting to get access to mysql externally. I think it\'s mysql or firewall stuff or some privilege within the mysql.

I already tried doing steps that are on int

Answer 1

Resumed solution:

I killed the mysqld that was holding the 3306 port and restarted it.

I think this is a bug or something related check step-by-step what I did:

1- Created a program to connect on 3306

First I create a simple program in Java to make sure there wasn't any problem with my firewall. The program just open a port on 3306 with TCP connection by 2 minutes just for testing, the program:

import java.io.IOException;
import java.net.ServerSocket;

public class PortMysqlTest {
    public static void main(String[] args) {
        int port = 3306;

        ServerSocket ss = null;
        try
        {
            ss = new ServerSocket(port);
            ss.setReuseAddress(true);
        }
        catch (IOException e)
        {
            System.out.println(e.getMessage());
        }

        long futureTime = System.currentTimeMillis() + 1000 * 60 * 2;
        while (System.currentTimeMillis() < futureTime)
        {
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        if (ss != null)
        {
            try
            {
                ss.close();
            }
            catch (IOException e)
            {
                System.out.println(e.getMessage());
            }
        }       
    }

2- Stopped the mysql service

Before executing the program I stopped the mysql service:

sudo service mysql stop

or it can be done with:

/etc/init.d/mysql stop

3- Started My program with java PortMysqlTest

My program (PortMysqlTest) throw an exception saying the address/port as already in use by mysqld!

Surprise? As far as I know the with mysql service stopped the port should be free. Am I right? (I'm not sure of it if someone can answer this...)

4- I searched for the application PID that was using the address/port with:

sudo netstat -lpn | grep 3306

the answer:

tcp        0      0 127.0.0.1:3306          0.0.0.0:*               LISTEN      6736/mysqld

5- I killed the process with:

kill -9 6736

OBS, if you don't know what kill do: 6736 is the process that was holding the port, I got this number with step 4, 6736/mysqld

6- Now I run my program again:

java PortMysqlTest and connected with telnet (telnet 66.123.173.170 3306) externaly and it worked!

So the problem wasn't the firewall, because I could connect externally to the machine 66.123.173.170.

7- Started the mysql service again:

(I waited 2 minutes for my program do stop and free the 3306 port) and started the mysql service again to test, with:

sudo service mysql start 

or

sudo /etc/init.d/mysql start

8- I did connected externally with telnet:

telnet 66.123.173.170 3306

and worked!!!

After I tried connect to mysql with:

mysql -h 66.123.173.170 -u root -p 

and worked!!!

Conclusion: I think there was a bug with my MySql installation; or something, (I don't know what is), when restarting mysql the mysql doesn't get the configuration of:

bind-address = 0.0.0.0 

or

bind-address = * 

I hope this help someone else.

Answer 2

Your netstat output shows that it is not open to external connections, it should show 0.0.0.0 in there instead of 127.0.0.1 (which is loopback, not local as such).

You probably need to add a different bind-address to your mysql config (and don't forget to restart the service).

Try

bind-address = *

or your actual NIC ip (66.123.173.170) perhaps.

Answer 3

Your need to set your bind-address in my.cnf to 0.0.0.0 not just comment out the line.

As a side note, you should probably not allow root access from all IP addresses as you say you have configured it. I would limit root to local machine only.

Answer 4

By default MySQL listen on localhost. You need to configure it to run on your actual interface or you can use 0.0.0.0 address in bind.