Source-Replica Tutorial

Last Update: January 2021

Exercise 3

In this exercise you will: prepare your MySQL-DB2 instance to become a replica

• 3.1 - Prepare MySQL-DB2

  Because we installed MySQL from the yum repository in Exercise 2, our data directory (by default /var/lib/mysql) now has basic information in it. We need to remove this because the backup/snapshot of our DB1 instance will contain some of these files. It is best to remove it before starting the process.

  rm -rf /var/lib/mysql/*

  Now that the data is gone, we need to start netcat in listen mode to receive the incomming backup stream from DB1 when we start it. Because port 3306 (the default MySQL port) must be open for normal MySQL operations, we are listening on that same port just in case firewalls or iptables are blocking other ports.

• 3.2 - Setup to Receive Backup

  Port 3306 (the default MySQL port) must be open for normal MySQL operations, so we are going to listen on that same port just in case firewalls or iptables are blocking other ports.

  cd /var/lib/mysql
  socat - TCP-LISTEN:3306 | xbstream -vx
  

  After pressing return on the above command, you will be presented with a newline. This is good and means socat is listening and waiting for data. Leave this terminal window open.