| Questions | End-user initiated DNS questions |
| Out-queries | Recursor initiated questions to other
nameservers |
| Throttled | If a certain nameserver is not responding, or if
it is, but returning unuseful answers, it is not useful to keep repeating
identical queries. If PowerDNS prevents a duplicate query, and therefore
prevents needless server load and delays, this is called a 'throttled
out-query' |
| Outgoing timeout | An out-query that did not generate an
answer within 1 or 2 seconds |
| Noerror answer | A Question that was answered without an error
status |
| NXDOMAIN answer | A Question that was answered with a positive
indication that there is no answer |
| SERVFAIL answer | No answer could be given because the nameservers
carrying the answer did not respond, or were throttled |
| Cache hits/misses | A query is judged a cache-hit if it could
be answered without generating any out-queries |
| User/System CPU usage | Actual amount of CPU used exclusively
by the recursor, either in user or in system (kernel) mode |
