# PowerDNS Recursor Performance Graphs

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