We are trying to monitor some MongoDB nodes with zabbix agent 2 version 6.0.26, as we need to authenticate with Mongo using TLS certificate we had to define a Session in config file as:

Plugins.MongoDB.System.Path=/usr/sbin/zabbix-agent2-plugin/zabbix-agent2-plugin-mongodb

Plugins.MongoDB.Sessions.Prod.Uri=tcp://d42amdmlshddb0.mongodb.DOMAIN.com:27017
Plugins.MongoDB.Sessions.Prod.User=zabbix
Plugins.MongoDB.Sessions.Prod.Password=********
Plugins.MongoDB.Sessions.Prod.TLSConnect=verify_ca
Plugins.MongoDB.Sessions.Prod.TLSCAFile=/etc/zabbix/mongo-ca.crt

We are using template MongoDB node by Zabbix agent 2, for this config we had to change items key to use Session and not connect string/user/pass macros.

Everything is looking fine regarding monitoring, items are able to gather stats, ping, collections and db list with Discovery rules.

The problem starts when we stop mongo db service, we got the alerts as we should for that but some minutes later the host in the frontend becomes unavailable throwing ZBX TCP Read TimedOut

Those Mongo items are zabbix agent (passive).