Recommended value for max-cache-size for cache-only shared hosts..
JINMEI Tatuya / 神明達哉
jinmei at isc.org
Tue Jun 5 18:30:54 UTC 2012
At Mon, 04 Jun 2012 12:53:31 -0700,
Doug Barton <dougb at dougbarton.us> wrote:
> >> If your cache is too small the CPU will peg when the cleaning-interval goes. Maybe that's changed but the behavior still exists in the 9.7 branch. Setting your cache size really depends on your query load. On a resolver doing 15,000/qps having a cache of 256M will cause a problem during the cleaning-interval whereas if it's 2G you won't notice the interval at all. Also on a busy resolver expect BIND to use about twice as much as where you set your limits.
> > Hmm, looking into the code again, I realized my memory was slightly
> > incorrect: "cleaning interval has been effectively no-op since BIND
> > 9.5" should have been "cleaning interval has been effectively
> > meaningless and therefore disabled by default since BIND 9.5", and if
> > you explicitly enable it by setting cleaning-interval to a non 0
> > value, it will still do meaningless but expensive operations.
> > So, in conclusion, my main point should still stand: "Tweaking it
> > (cleaning-interval) won't improve performance". And, it could
> > actually do harm.
> Thanks, I learned something today! But that sort of prompts the question
> in my mind, why does the option still exist?
Good question, I wonder the same thing:-) I don't remember the
original plan, but I guess it was actually planned to be deprecated
but it has just been forgotten or left as a lower priority thing since
Internet Systems Consortium, Inc.
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