Recover This Crashed MariaDB Galera Cluster

15 minutes
  • 3 Learning Objectives

About this Hands-on Lab

In this activity you are working as a DBA and have been tasked with recovering a crashed MariaDB Galera cluster.

Learning Objectives

Successfully complete this lab by achieving the following learning objectives:

Determine the Most Advanced Node

We can check the sequence number of the node:

sudo -u mysql mysqld --wsrep_recover

Run this on all nodes, and the highest sequence number is the most advanced node.

Bootstrap the Most Advanced Node

Edit the node configuration in /etc/my.cnf.d/:

wsrep_cluster_address=gcomm://

Start the node:

sudo systemctl start mariadb.service
Check Status and Add Nodes to the Cluster

Connect with mysql client and query status variables:

SHOW GLOBAL STATUS WHERE Variable_name IN ('wsrep_ready', 'wsrep_cluster_size', 'wsrep_cluster_status', 'wsrep_connected');

Edit the node configuration in /etc/my.cnf.d/. Be certain to use the private IP of the running node:

wsrep_cluster_address=gcom://10.0.0.110

Start the node:

sudo systemctl start mariadb.service

Additional Resources

In this activity you are working as a DBA and have been tasked with recovering a crashed MariaDB Galera cluster. All nodes are currently stopped. In order to recover the cluster, you will need to complete the following steps:

  1. Determine the most advanced node.
  2. Bootstrap the most advanced node.
  3. Check the status and add nodes to cluster.

What are Hands-on Labs

Hands-on Labs are real environments created by industry experts to help you learn. These environments help you gain knowledge and experience, practice without compromising your system, test without risk, destroy without fear, and let you learn from your mistakes. Hands-on Labs: practice your skills before delivering in the real world.

Sign In
Welcome Back!

Psst…this one if you’ve been moved to ACG!

Get Started
Who’s going to be learning?