MySQL in a Nutshell, 2nd Edition

Configuring the Servers

Once the replication user is set up on both servers, you will need to add some lines to the MySQL configuration file on the master and on the slave server. Depending on the type of operating system, the configuration file will probably be called either my.cnf or my.ini. On Unix types of systems, the configuration file is usually located in the /etc directory. On Windows systems, it’s usually located in c:\ or in c:\Windows. If the file doesn’t exist on your system, you can create it. Using a plain text editor (e.g., vi or Notepad.exe)—one that won’t add binary formatting—add the following lines to the configuration file of the master under the [mysqld] group heading:

[mysqld]
server-id = 1
log-bin = /var/log/mysql/bin.log
...

The server identification number is an arbitrary number used to identify the master server in the binary log and in communications with slave servers. Almost any whole number from 1 to 4294967295 is fine. Don’t use 0, as that causes problems. If you don’t assign a server number, the default server identification number of 1 will be used. The default is all right for the master, but a different one should be assigned to each slave. To keep log entries straight and avoid confusion in communications between servers, it is very important that each slave have a unique number.

In the configuration file excerpt shown here, the line containing the log-bin option instructs MySQL to perform binary logging to the path and file given. The actual path ...