Using data triggers to control relays


I’m very new to emoncms and would like to use it to monitor my energy consumption and production of the PV array. I already got scripts that dump energy etc. into a DB. What I’m lacking is a nice frontend which I understand emoncms does provide.
Additionally I’d like to control external relays through triggers (e.g. turn on water heater if there is excessive power from the roof).
The HW used is a RPI with external relay card.
Is it possible to create triggers based on the content (or calculated out of content) with the current emoncms? I did see that the event monitor is no longer supported with the latest version of emoncms.
Is emoncms the tool best suited for such a task?
Is it easily possible to migrate the existing data in the DB the the emoncms structure?

thanks for your adivce