I have an application connected to a MySQL database, but sometimes when I update my app this message appears

[Eduardo_dos_San]

I have an application connected to a MySQL database, but sometimes when I update my app this message appears.

any tips not to happen this anymore?

[Steve]

As the errors say, the app is being blocked from getting to your database. You’ll need to look for a problem there. Given that the problem is intermittent, I would suspect your database, or a firewall and/or proxy server in front of the database, is overloaded or rate-limiting connections.

[MultiTech]

Steve:

overloaded or rate-limiting connections

Indeed.