Empty graph on netstat monitoring

[sevmax]

Hi zabbix community,
Please guide about following question.
I'm trying to monitor number of opened connections to MySQL using netstat.
On DB server I created file: /etc/zabbix/agent.d/netstat.conf

UserParameter=netstat_mysql_connection,netstat -ntp | grep mysql | grep ESTABLISH | wc -l

And added this trigger to Zabbix server. It is shown as monitored item, but graph is empty.

Two questions:
1. What should I modify to make graph working ?
2. Is there any better way to get number of connections to MySQL server on port 3306?

Thank you in advance!

[nickiv]

Hello, sevmax.

Most surely your empty graph is result of running zabbix agent under sestricted Linux User.

Netstat -p parameter requires superuser privileges. You can confirm it by running your command after changing user to zabbix, like that:

su zabbix
netstat -ntp | grep mysql | grep ESTABLISH | wc -l
exit

I dont know yet how to overcome this limitation of netstat. But you can monitor Mysql Connections through server status.

mysqladmin -uroot status -p<password>|cut -f2 -d":"|cut -f1 -d"T"

[sevmax]

Thank you, nickiv.
I was experimenting and found that this construction is working:

netstat -nt | grep 3306 | grep ESTABLISH | wc -l