Recommended value for max-cache-size for cache-only shared hosts..

Doug Barton dougb at
Mon Jun 4 19:53:31 UTC 2012

On 06/04/2012 11:36, JINMEI Tatuya / 神明達哉 wrote:
> At Fri, 1 Jun 2012 21:14:06 +0000,
> Dan Mason <danmason at> wrote:
>>> cleaning interval has been effectively no-op since BIND 9.5.  Tweaking
>>> it won't improve performance, although it shouldn't cause a bad effect
>>> either.
>> 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?


    If you're never wrong, you're not trying hard enough

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