Ticket 236 ‐ Resolve MariaDB Service Check Failures in Nagios - SupaHotBall/OE2-Group-D GitHub Wiki

Task

  • Diagnose Monitoring Failure:
  • Review current Nagios MariaDB check configuration
  • Examine service check logs and error messages
  • Verify MariaDB server accessibility and credentials
  • Implement Fixes per Lab 07.1:
  • Update check_mysql command parameters.
  • Adjust timeout and retry settings if needed.
  • Validate proper database user permissions.cfg.
  • Testing & Validation:
  • Manually test the updated monitoring configuration.
  • Verify successful checks in Nagios web interface.
  • Confirm alerting works as expected.

Steps Taken

Check that MariaDB is running on the DB server

systemctl status mariadb

image

Test the check command manually

/usr/lib/nagios/plugins/check_mysql -H db-d

image

The output should match the error on the Nagios web interface

image

Log in to MariaDB shell with the default root user

sudo my sql -u root -p

image

Run the following command to perform a select query on a nonexistent database which is enough for Nagios check to pass

GRANT SELECT ON nagiosdb.* TO 'nagios'@'13.75.179.27' IDENTIFIED BY 'mypasswd';

image

Run the command below on the management server (use the same password as the password in the query in mariadb server)

/usr/lib/nagios/plugins/check_mysql -H db-d -u nagios -p rushhour

image

Edit this line in the puppet module config.pp file. It should pass in the values of the user and the password created earlier

check_mysql_cmdlinecred!nagios!rushhour

image

Ensure that puppet agent test is ran to apply the configuration everytime the config.pp file is updated

sudo puppet agent --test

image

Restart the nagios4 service

image

Verify that the Nagios check is passing

image

Challenges

The first time a user was created, the db server wouldn't connect still due to permission issues. In order to resolve this, the user was deleted and then recreated and had flush privileges applied to it. After this, connection was successful.

image

MariaDB server conf file was not configured correctly and this needs to be fixed before proceeding

External Resources

N/A

Ticket Reference

https://rt.dataraster.com/Ticket/Display.html?id=236