On Sun, Jun 14, 2015 at 10:43 PM, Mark H Weaver wrote: > On my GuixSD system, DNS lookup failures (due to lack of network) are > cached for at least 4 minutes, and possibly much longer (I've not had > the patience to wait until it expires). > > Even after restarting nscd, the negative cache entry persists for about > another 20 seconds. > > I run into this problem quite frequently after waking my system up from > suspend-to-ram. It typically takes several seconds for wicd to > establish a network connection, and if I make the mistake of triggering > a name lookup of my server (world.peace.net), then I must do the > following: > > (1) deco restart nscd > (2) wait about 20 seconds > > Looking at %nscd-default-caches in (gnu services base), I see that the > intent is to cache host lookup failures for 20 seconds, and service > lookup failures for an hour. The fact that the negative cache entry > persists for 20 seconds after restarting nscd would seem to indicate > that nscd considers this to be a host lookup. So perhaps this is a bug > in nscd. > > Is anyone else able to reproduce this problem? Yes, I had this exact same issue on Friday after having wireless network connectivity problems. - Dave