1. Check the error log for the MySQL 1780 error:
$ tail -f /var/log/mysql/error.log
2. Check the MySQL configuration file for any misconfigurations:
$ cat /etc/mysql/my.cnf
3. Check the MySQL process list to see if any queries are running for a long time:
$ mysqladmin -u root -p processlist
4. Check the MySQL status to see if there are any issues with the server:
$ mysqladmin -u root -p status
5. Check the MySQL variables to see if any of them are set incorrectly:
$ mysqladmin -u root -p variables
6. Check the MySQL user privileges to see if any of them are set incorrectly:
$ mysql -u root -p -e "SELECT * FROM mysql.user;"
7. Check the MySQL database tables to see if any of them are corrupted:
$ mysqlcheck -u root -p --all-databases
8. Check the MySQL query cache to see if any of the queries are taking too long to execute:
$ mysqladmin -u root -p flush-query-cache
9. Check the MySQL slow query log to see if any of the queries are taking too long to execute:
$ mysqladmin -u root -p slow-query-log
10. Once the issue is identified, take the necessary steps to fix it.11. After the issue is fixed, it is recommended to use an automated database observability tool to monitor and fix the MySQL 1780 in question. This tool can help identify any potential issues before they become a problem, as well as provide insights into the performance of the database. It can also provide alerts when certain thresholds are exceeded, allowing for quick resolution of any issues that may arise.