Question

I am trying to connect to MySQL database over a network. I have installed MySQL, and the service is running on the default port. I have also install the SQL connector to the jar file and added java JDK to the server machine. I am able to connect to my local database using the code:

private String dbUrl = "jdbc:mysql://localhost/DatabaseName";
private String dbClass = "com.mysql.jdbc.Driver";

But when I try and connect to it over the network, with the IP address (eg: 192.168.1.45):

private String dbUrl = "jdbc:mysql://192.168.1.45/DatabaseName";
private String dbClass = "com.mysql.jdbc.Driver";

I get the connection error:

Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

Does anyone know what this issue is? Do I need to add a different address?
I have added the default port with the address but cannot get it to work.

Thanks for any help.

Answer 1

1. Check the my.cnf [mysqld] settings for the parameters port, bind-address, socket, to make sure these aren’t causing problems.
2. Check the files /etc/hosts, /etc/hosts.deny to make sure everything is ok.
3. Check firewall applications
4. Check to make sure whatever directory mysqld’s sockets are have the appropriate permissions.
5. Check to make sure that security settings within the mysql database (user table) permit access from your remote host.
6. Make sure you can telnet OK to localhost 3306, 127.0.0.1 3306, and whatever other IP address your machine is configured to (use ifconfig to find out).