2011/6/14 Mike Ruiz <mr...@zynga.com>: > Hello All, > We use dnsmasq as a very effective replacement for the ISC software, thus > far with great success. However, we have run into occasional performance > problems at scale. > These seem to manifest as a general slowdown of the request -> reply > process, which can sometimes exceed 90 seconds from request to reply. [snip] > Are there any obvious inflection points that would cause the server to drop > in performance by a few orders of magnitude with lots of hosts defined? Are > there any recommendations for tuning, beyond introducing more dnsmasq > servers?
Hmmm, this sounds like some O² or worse scaling code... Can you run some tests? Compile dnsmasq with -g, and run it under valgrind like this: valgrind --tool=callgrind --dump-instr=yes --collect-jumps=yes --simulate-cache=yes --simulate-hwpref=yes --cacheuse=yes dnsmasq --dnsmasq-options Now let it hand out a dhcp allocation, and stop it afterwards. You should get a callgrind.out.$pid and can feed it into kcachegrind. > -Mike Greetings Jan -- Murphy's Law of Combat Rule #3: "Never forget that your weapon was manufactured by the lowest bidder"
