In message <20160218185957.ga2...@mycre.ws>, Robert Edmonds writes: > Tony Finch wrote: > > Tony Finch <d...@dotat.at> wrote: > > > > > > Funnily enough I recently wrote a tool to do this but I have been failing > > > to publish a blog article about it... Have a look at this: > > > https://git.csx.cam.ac.uk/x/ucs/ipreg/adns-masterfile.git > > > > Longer blurb now published at: http://fanf.livejournal.com/141030.html > > A large proportion of records are only ever used "once, or a handful of > times", according to researchers: > > http://www.cc.gatech.edu/~ynadji3/docs/pubs/dnsnoise-dsn2014.pdf > > ("DNS Noise: Measuring the Pervasiveness of Disposable Domains in > Modern DNS Traffic") > > If there were some way to only dump the most popular records from the > cache (say the top 1,000 or 10,000), it would probably speed up the > pre-heating process significantly and still warm the cache to an > acceptable degree. > > Does rndc dumpdb dump the cache in DNS tree order, or could it be > convinced to follow the LRU order?
Or realise that it isn't worth the effort to do this. The DNS is actually fast enough to not have to warm the cache. If one wants to spend time fixing things go through the Alexa top 1M and complain to every operator that still has a server that returns FORMERR to a EDNS query. That will have more benefit than any cache warming code and nameservers have to constantly re-learn that a server doesn't support EDNS and that takes multiple round trips. Go through the top 1M and complain to those that don't respond to unknown QTYPE e.g. TYPE666 or respond with NOTIMP/REFUSED or respond with a invalid negative answer (e.g. wrong SOA, NXDOMAIN instead of NODATA). Getting rid of broken servers will provide much more benefit then saving a couple of seconds when a server is restarted. Not only do these errors cause slow lookups, they have put back application development years. Mark > -- > Robert Edmonds > _______________________________________________ > Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe > from this list > > bind-users mailing list > bind-users@lists.isc.org > https://lists.isc.org/mailman/listinfo/bind-users -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
