Bind 8.1.2 in.named memory leak in Solaris 7

[Jim Reid]

>>>>> "Joaquim" == Joaquim Eudes Mendes Gomide <jgomide at bancobrasil.com.br> writes:

    Joaquim> I got an article on Sunsolve that says: "The DNS process
    Joaquim> ´in.named´ continually consumes memory until no
    Joaquim> memory is available. At this point in.named terminates
    Joaquim> leaving a possibly large core file."  Is this problem a
    Joaquim> Bind 8.1.2 or a Solaris version of Bind bug? The same
    Joaquim> article says that there is no work around, too.  Does the
    Joaquim> Bind 8.2 solves this problem?

The article is a little bit misleading. It gives the impression that
name servers guzzle memory until the system runs out and then named
crashes and dumps core. This isn't quite true. It is true that the
name server will die if it cannot get more memory from the OS. However
that should be a rare event. And if your system can't let the name
server process have more memory, then you have to contend with more
serious underlying problems. [Like a grossly overloaded computer or a
woefully inadequate local DNS infrastructure.]

The size of a name server process grows as it receives queries. These
make named cache more and more data as it looks up names and sends
queries to other name servers. However the size of the process tends
to stabilise after the name server has been running for a few
days. Old entries get expired from the cache and the lookup patterns
from local resolvers tend to request the same names.

This "problem" is the way name servers work. They take more memory
from the OS as they need to cache resource records. In general this
doesn't grow without limit. I believe that BIND9 will behave more
gracefully when named's memory allocation requests fail. However this
isn't due to be released until next year and it may be a year after
that before vendors ship it with their OS releases.

FWIW the name server on a Solaris box here has been running for a few
weeks now and it only uses 1.5M of VM. This isn't a noticeable load on
the system and is nowhere near the resource limits of the OS.