[Pdns-users] Interpreting server variables
jp at mens.de
Fri Oct 5 12:36:49 UTC 2007
I'd appreciate a bit of help in interpreting some server variables for
a performance comparison chapter.
With the following pdns.conf
I'm getting these values:
corrupt-packets 0 Number of corrupt packets received
deferred-cache-inserts 62746 Amount of cache inserts that were deferred because of maintenance
deferred-cache-lookup 6350 Amount of cache lookups that were deferred because of maintenance
latency 2 Average number of microseconds needed to answer a question
qsize-q 0 Number of questions waiting for database attention
query-cache-hit 158314 Number of hits on the query cache
query-cache-miss 690664 Number of misses on the query cache
servfail-packets 0 Number of times a server-failed packet was sent out
timedout-packets 0 Number of packets which weren't answered within timeout set
udp-answers 2450270 Number of answers sent out over UDP
udp-queries 2450270 Number of UDP queries received
udp4-answers 2450270 Number of IPv4 answers sent out over UDP
udp4-queries 2450270 Number of IPv4UDP queries received
I'm hitting the server with 2.5 million synthetic queries which remain
constant. There are queries for CNAME, A, MX, NS, SOA, etc. which are
being sent in constant fashion to the PowerDNS server..
If I've studied the documentation correctly, it is good that qsize-q
is very low.
I don't understand why packetcache-miss / query-cache-miss are so
high. I'd have thought that the ttl of the query/negative-query would
answer the packet from the cache. Isn't that the case?
Sending the server a constant stream of identical queries (also
queries which result in NXDOMAIN or SERVFAIL) show expected results:
Can someone kindly help me with this, perhaps also pointing out
whether the cache parameters could be sensible?
BTW, Is there a method of configuring a packet cache size?
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