[Pdns-announce] PowerDNS Recursor 3.1.2 released!

[bert hubert]

After extensive testing, we are proud to announce PowerDNS Recursor version
3.1.2.

Compared to 3.1.1, this release consists almost exclusively of bug-fixes
and speedups. A quick update is recommended, as some of the bugs impact
operators of authoritative zones on the internet. This version has been
tested by some of the largest internet providers on the planet, and is
expected to perform well for everybody.

Available at:

. http://downloads.powerdns.com/releases/pdns-recursor-3.1.2.tar.bz2
. http://downloads.powerdns.com/releases/rpm/pdns-recursor-3.1.2-1.i386.rpm
. http://downloads.powerdns.com/releases/rpm/pdns-recursor-3.1.2-1.x86_64.rpm
. http://downloads.powerdns.com/releases/deb/pdns-recursor_3.1.2-1_amd64.deb
. http://downloads.powerdns.com/releases/deb/pdns-recursor_3.1.2-1_i386.deb

Changelog with clickable links describing each change on
http://doc.powerdns.com/changelog.html , text version:

 Many thanks are due to Darren Gamble, Stefan Schmidt and Bryan Seitz who
 all provided excellent feedback based on their large-scale tests of the
 recursor.

 Bug-fixes:

   * Internal authoritative server did not differentiate between 'NXDOMAIN'
     and 'NXRRSET', in other words, it would answer 'no such host' when an
     AAAA query came in for a domain that did exist, but did not have an
     AAAA record. This only affects users with auth-zones configured.
     Discovered by Bryan Seitz, fixed in commit 848.

   * ANY queries for hosts where nothing was present in the cache would not
     work. This did not cause real problems as ANY queries are not reliable
     (by design) for anything other than debugging, but did slow down the
     nameserver and cause unnecessary load on remote nameservers. Fixed in
     commit 854.

   * When exceeding the configured maximum amount of TCP sessions, TCP
     support would break and the nameserver would waste CPU trying to
     accept TCP connections on UDP ports. Noted by Bryan Seitz, fixed in
     commit 849.

   * DNS queries come in two flavours: recursion desired and non-recursion
     desired. The latter is not very useful for a recursor, but is
     sometimes (erroneously) used by monitoring software or loadbalancers
     to detect nameserver availability. A non-rd query would not only not
     recurse, but also not query authoritative zones, which is confusing.
     Fixed in commit 847.

   * Non-standard DNS TCP queries, that did occur however, could drive the
     recursor to 100% CPU usage for extended periods of time. This did not
     disrupt service immediately, but does waste a lot of CPU, possibly
     exhausting resources. Discovered by Bryan Seitz, fixed in commit 858,
     which is post-3.1.2-rc1.

   * The PowerDNS recursor did not honour the rare but standardised 'ANY'
     query class (normally 'ANY' refers to the query type, not class),
     upsetting the Wildfire Jabber server. Discovered and debugged by
     Daniel Nauck, fixed in commit 859, which is post-3.1.2-rc1.

   * Everybody's favorite, when starting up under high load, a bogus line
     of statistics was sometimes logged. Fixed in commit 851.

   * Remove some spurious debugging output on dropping a packet by an
     unauthorized host. Discovered by Kai. Fixed in commit 854.

 Improvements:

   * Misconfigured domains, with a broken nameserver in the parent zone,
     should now work better. Changes motivated and suggested by Darren
     Gamble. This makes PowerDNS more compliant with RFC 2181 by making it
     prefer authoritative data over non-authoritative data. Implemented in
     commit 856.

   * PowerDNS can now listen on multiple ports, using the local-address
     setting. Added in commit 845.

   * A number of speedups which should have a noticeable impact,
     implemented in commits 850, 852, 853, 855

   * The recursor now works around an issue with the Linux kernel 2.6.8, as
     shipped by Debian. Fixed by Christof Meerwald in commit 860, which is
     post 3.1.2-rc1.

-- 
http://www.PowerDNS.com      Open source, database driven DNS Software 
http://netherlabs.nl              Open and Closed source services