Wildfly supports monitoring over http-remoting-jmx protocol and Zabbix uses rmi. So is it good practise to use "standard" way of specifying JMX (in the Java opts) in the Wildfly? Or how can i achieve monitoring Wildfly using Zabbix?
Usually the applications that support remoting-jmx do no not work very well with rmi. You can patch the Java gateway to support remoting-jmx - there are community patches floating around. Keep in mind that it is completely unsupported. This support is supposedly coming with Zabbix 3.4 - see https://support.zabbix.com/browse/ZBXNEXT-1274 .