Galera

Galera

This section describes the alerts for the Galera cluster.


GaleraServiceDown

Severity

Minor

Summary

The Galera service on the {{ $labels.host }} node is down.

Raise condition

mysql_up != 1

Description

Raises when MySQL on a host does not respond to Telegraf, typically indicating that MySQL is not running on that node. The host label in the raised alert contains the name of the affected node.

Troubleshooting

  • Verify the MySQL status on the affected node using service mysql status.

  • If MySQL is up and running, inspect the Telegraf logs on the affected node using journalctl -u telegraf.

Tuning

Not required

GaleraServiceOutage

Severity

Critical

Summary

All Galera services within the {{ $labels.cluster }} cluster are down.

Raise condition

count(label_replace(mysql_up, "cluster", "$1", "host", "([^0-9]+).+")) by (cluster) == count(label_replace(mysql_up == 0, "cluster", "$1", "host", "([^0-9]+).+")) by (cluster)

Description

Raises when all MySQL services across the cluster do not respond to Telegraf, typically indicating deployment or configuration issues.

Troubleshooting

  • Verify the MySQL status on any Galera node using service mysql status.

  • If MySQL is up and running, inspect the Telegraf logs on the affected node using journalctl -u telegraf.

Tuning

Not required

GaleraNodeNotReady

Severity

Major

Summary

The Galera service on the {{ $labels.host }} node is not ready to serve queries for 1 minute.

Raise condition

mysql_wsrep_ready != 1

Description

Raises when the Write Set Replication (WSREP) in the MySQL service is not ready, typically indicating that the MySQL process is running but the WSREP is not in the ready state, meaning that the node is not a part of the Galera cluster.

Troubleshooting

Inspect the MySQL logs on the affected node using journalctl -u mysql.

Tuning

Not required

GaleraNodeNotConnected

Severity

Major

Summary

The Galera service on the {{ $labels.host }} node is not connected to the cluster for 1 minute.

Raise condition

mysql_wsrep_connected != 1

Description

Raises when the Write Set Replication (WSREP) in the MySQL service is not in the connected state, typically indicating that the MySQL process is running but the WSREP did not establish the required connections with other nodes within the Galera cluster due to the WSREP misconfiguration in MySQL or a network issue.

Troubleshooting

  • Inspect the MySQL logs on the affected node using journalctl -u mysql.

  • Verify if proper hosts are used in Galera.

Tuning

Not required