This only works, if the services don't need to open any priviledged ports (< 1024). Of course you could run the webserver as root, but that can create security risks! Therefore NeDi's Syslog (syslog.pl) and snmptrapd run on high-ports and usually are redirected by an internal firewall.
At the end of a run the nodes table needs to be locked during calculation, with that no other thread meddles with them. Furthermore should Top RRDs only be taken care of by the last thread to finish or they're gonna look like Picassoes.
On the far right you see the discovery status (# of threads is revealed by hovering over . If the nodes table is locked a
is shown next to it.
In case a discovery terminated unexpectedly or a nodelock hangs, you can reset it
by clicking on
.