If enabling the 'Kill slow SELECT queries' feature in MySQL Governor doesn't seem to help, it could be due to various reasons. Below are steps you can take to further troubleshoot the issue:

1. Verify Configuration:

   • Double-check that the 'Kill slow SELECT queries' feature is properly configured in MySQL Governor. Ensure that the threshold for what is considered a "slow" query is set appropriately.

2. Check MySQL Logs:

   • Review MySQL logs (/var/log/mysql/error.log) to see if there are any indications of slow queries that should have been killed by MySQL Governor. This can help determine if the feature is functioning correctly.

3. Check MySQL Governor Logs:

   • Inspect the logs for MySQL Governor (/var/log/governor.log or similar location) to see if there are any relevant messages related to killing slow queries. This can provide additional information on whether the feature is working as expected.

4. Verify MySQL Governor Version:

   • Ensure that you're using a version of MySQL Governor that supports the 'Kill slow SELECT queries' feature. Older versions may not have this functionality.

5. Check for Other Resource Limitations:

   • If your server is under heavy load or experiencing resource constraints, it's possible that MySQL Governor is not able to act on slow queries due to other limitations.

6. Optimize Slow Queries:

   • Consider reviewing and optimizing the slow queries themselves. Improving the performance of the queries can help alleviate the need to kill them.

7. Review MySQL Configuration:

   • Check MySQL configuration settings to ensure that it's properly configured for your workload. Settings like max_execution_time and max_allowed_packet can impact query performance.

8. Check for Locking Issues:

   • Slow queries can sometimes be a result of locking issues. Check if there are any long-running transactions that might be causing delays.

9. Monitor MySQL Performance:

   • Use monitoring tools to keep an eye on MySQL performance in real time. This can help identify any spikes in slow query occurrences.

10. Update or Reinstall MySQL Governor:

    • If you're using an older version of MySQL Governor, consider updating to the latest version. If the issue persists, you might even consider reinstalling it.

11. Consult with MySQL Governor Support:

    • If none of the above steps work, consider reaching out to MySQL Governor support for further assistance. They may have specific troubleshooting steps or solutions for this issue.

Always exercise caution when making changes to system configurations, and ensure that you have backups available before making significant modifications. If you're uncertain about any of the steps, consider seeking advice from your hosting provider or system administrator.