Failed to reset cache

I have received “WordPress Updates Digest” notification email from cPanel stating that it “Failed to reset cache” on 3 different WP sites. The websites along with the plugins were manually updated yesterday. So, there was nothing else to update. The websites were functioning fine when I viewed them immediately after receiving this notification.

This is how the memory limit configuration looks like on the websites:
staging.mysite1.com/site1 – 128MB (PHP 8)
mysite1.com – 32MB (PHP 8)
staging2.mysite2.com/site2 – 512MB (PHP 5.6)

The websites are simple informational sites and don’t have too much traffic. The 2 staging sites I mentioned above don’t get any external traffic and are not currently in use.

I’ve got this email twice this month. Not sure what’s triggering this issue and how to fix this.

This is what the full email looked like:

Updates were not installed for the following items:

1. Website "/home/staging/public_html/site1" (http://staging.mysite1.com/site1):
Failed to reset cache for the instance #1: Warning: mysqli_real_connect():
(HY000/2002):
Connection refused in /home/staging/public_html/site1/wp-includes/wp-db.php on line 1753
Error: <code>Connection refused</code>
Error establishing a database connection
This either means that the username and password information in your <code>wp-config.php</code>
file is incorrect or we can’t contact the database server at <code>localhost:3306</code>.
This could mean your host's database server is down.
Are you sure you have the correct username and password?
Are you sure you have typed the correct hostname?
Are you sure the database server is running?
If you're unsure what these terms mean you should probably contact your host.
If you still need help you can always visit the WordPress Support Forums. <code>Connection refused</code>

2. Website "/home/mysite/public_html" (http://mysite1.com):
Failed to reset cache for the instance #2:
Error: Error establishing a database connection.

3. Website "/home/staging2/public_html/site2" (http://staging2.mysite2.com/site2): 
Failed to reset cache for the instance #3:
Error: Error establishing a database connection.
This either means that the username and password information in
your <code>wp-config.php</code> file is incorrect or we can't contact the database server at <code>localhost</code>.
This could mean your host’s database server is down.

• This topic was modified 4 years ago by wrip.