Non-persistent MySQL connections are not being closed in Cacti.

Description

I have been investigating a problem with Cacti where it opens a new database connection on every 5 minute poll interval, and never closes them, eventually running the DB server out of connections, even with the max_connections set to 1000. It is a new install of Cacti, I am not upgrading.

Eventually I figured out that configuring Cacti to use persistent database connections solved the issue. So there is a workaround.

I am seeing the biggest problem with the long-running daemons, one for cacti itself called cactid, the other for a cacti plugin called flowview. The service for that one is called "flow-capture".

The cacti project is claiming that they have never had to worry about closing connections before and they think something probably changed in PDO.

This is the issue I opened on Cacti for the problem:

https://github.com/Cacti/cacti/issues/5401

PHP Version

PHP 8.1.2-1ubuntu2.13

Operating System

Ubuntu 22.04

Comienza reproduciendo el crecimiento de conexiones en los daemons cactid y flow-capture bajo PHP 8.1.2 con conexiones MySQL no persistentes, utilizando el issue enlazado de Cacti como contexto. Rastrea el ciclo de vida de la conexión PDO durante sondeos repetidos de cinco minutos; se considera terminado cuando las conexiones se liberan en lugar de acumularse hasta que MySQL alcanza su límite.