如何在Centos中使用MySql连接到远程服务器？

Question

I am new to hadoop. I am practicing hadoop on cloudera environment. I am trying to connect to remote server using mySql (which is pre-installed in cloudera), but it's not connecting.

Actually my main intention is to run a job by importing data from remote server using Sqoop and to store it in HDFS location. But getting error as

Communication link failure

So, first I am trying to connect with the help of mySql, but here also getting error as unable to connect to server.

mysql -u "username" -h "xxx.xxx.xx.xxx(ip address)" -p

It's not connecting. give error message as

Error: Unable to connect to mysql server "xxx.xx.xxx.xx"

If I am trying to connect to localhost it's working good,

mysql -u root -p

Should I need to do any changes in config files to connect to remote server for importing of data from database to HDFS via Sqoop.

Can anyone please suggest me how to connect to remote server by using mysql from centOs - Cloudera environment.

Answer 1

If I understood correctly:

• when you are connecting to your MySQL server locally with mysql -u root -p it works
• when you are connecting to the same server from a remote server it does not works

If this is your issue you most likely need to edit the file /etc/mysql/my.cnf on the MySQL server and add the public server IP in bind-address=[public_ip] and restart MySQL.

You also need to ensure your user is allowed to access the server remotely or you will have to create a remote user. You can see users and their allowed origin from:

SELECT Host, User FROM mysql.user;

Finally you might have a firewall (like ufw ) on your server preventing you from accessing the MySQL port (by default 3306 ) remotely. If this is the case, you need to allow connections from your remote server in your firewall.