There are two execution modes for Plugins:
1) on Demand The Plugin is executed when you click on a network to achive the Details-View (such as the "DNSInfo-Plugin", which queries the PTR-Record of the IP-Address, or the "RIPEInfo"-Plugin, which queries´the RIPE-DB for the network on demand).
2) recurrent The Plugin is executed by the HaCid-Daemon, which is either running as Daemon (without options) or being called by CRON (with -c option, in order to exit after on full cycle through all Plugins). Each recurrent Plugin has an Interval-Option, which determines when the Plugin should be called. All networks, which were configured to use the Plugin, are passed to the Plugin at execution time. The results are stored in the database, so that HaCi could show them in the Details-View (E.g. the Plugin "DNSInfoForNetworks", which collects all PTR-Records for the specified networks in background).
HaCi Daemon (bin/HaCid.pl)
The HaCi daemon is responsible for the recurrent plugins. It runs them in defined intervals. You can start it with the parameter -c therewith it exists after one full run and you can start it by crontab. The daemon stores its PID in the spool- and writes its logfile in the logs directory. So it must have write permissions to this directories.