Nagios/SQL crash of Journal Suppressed messages

[brucej543]

Running Nagios XI 5.6.14. The application crashed after getting the below message from running out of memory: Message is from the /var/log/messages file
Jul 22 11:01:06 bcnagios01 journal: Suppressed 4150 messages from /system.slice/ndo2db.service
Jul 22 11:01:06 bcnagios01 ndo2db: Error: Could not connect to MySQL database: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2) (This message repeated until system crashed)

Ran database repair script after hard reboot.
Truncated both the nagios_logentries and nagios_notifications tables and reran the database repair script.

What would be the cause of this issue.

[brucej543]

Close this post. Opening a new post regarding this issue. New post will have subject of "nagios_downtimehistory is marked as crashed"

[tgriep]

I will close this post and answer in the other post.