Maintained by: NLnet Labs

[Unbound-users] ~10% performance increase in worker_handle_request()

Robert Edmonds
Mon Jan 6 19:46:46 CET 2014


W.C.A. Wijngaards wrote:
> However, moving the check after the cache check is not a good idea.
> The localzone and localdata statements are supposed to be able to
> override the DNS contents from the internet.  Checking it earlier
> means that this always happens.  Messing with cache flushes sounds
> very bad, a query may create a recursive query that would then
> override the configuration and so on, lots of complexity as well as
> worries about giving the 'wrong' answers (as compared to the
> configuration).

OK, that makes sense.

> It would be better to optimise the localzone lookup itself somehow.
> Not sure what the best way is, it is visible that it uses a rbtree now
> and that this is slower than the hashtable that the other cache employs

Yes, the problem is not that the localzone lookup occurs first, per se,
but that the localzone lookup causes measurable contention with other
threads.

-- 
Robert Edmonds
edmonds at debian.org