"Me too". I just spent half a day tracking down why my Django development server running under Feisty was taking 20 seconds to serve a simple web page to another machine on the same LAN, and finally tracked it down to this issue. Specifically, the client machine was on a private network (IP address 10.0.1.1) and the local DNS server was configured with an empty 10.in-addr.arpa.zone, causing it to return an NXDOMAIN response for the reverse mapping.
The django server was calling gethostbyaddr() on the client address (10.0.1.1) for each HTTP request, and each gethostbyaddr() call took about about five seconds to complete. On my other, non-Ubuntu machines, it would return almost instantly (within a few milliseconds). When I changed the "hosts" line in /etc/nsswitch.conf to hosts: files dns the problem went away - the page that took 20 seconds to load now loads in a small fraction of a second. It's not reasonable for the lack of a reverse mapping in the DNS to cause a long delay. On other operating systems, it simply causes the gethostbyaddr() call to quickly return with h_errno=HOST_NOT_FOUND, and Ubuntu should behave the same way. Long delays in gethostbyname() and gethostbyaddr() are of course to be expected if the DNS server is not responding, but that is not the case here - the server is responding quickly, but with an NXDOMAIN, indicating that no reverse mapping exists. -- mdns listed in nsswitch.conf causes excessive time for dns lookups https://bugs.launchpad.net/bugs/94940 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
