While looking for Varnish error code statistics in Graphite under reqstates. I found out it is cluttered with metrics for each of our Wiki domain.
The related script is most probably files/udp2log/sqstat.pl in puppet which has been introduced 3 years ago by Asher. Each branch has three metrics: pageview, tp50 and tp99.
Since they seem empty, maybe we should phase them out? I am not sure whether sqstats.pl is still in use though.