nscd frequent assertion failure...

Petr Baudis pasky at ucw.cz
Sat Nov 22 19:08:50 UTC 2008


On Sat, Nov 22, 2008 at 12:54:18PM +0000, Daniel J Blueman wrote:
> glibc 2.8's name-service cache daemon (nscd) is seeing frequent
> assertion failure [1], at least in Ubuntu 8.10, due to internal
> consistency checks failing (memory object misalignment). Right now in
> the 8.10 Intrepid cycle, this is 100% of the crashes I've had over the
> last week's workflow.
> Since nscd is not installed by default on many distros, this isn't
> getting the minimum exposure and attention to get addressed, sadly.
> I've been unable to find any fixed/unfixed bug reports, and I've
> tracked this with valgrind [2].
> Is anyone else seeing this, and has any suggestions about the best way forward?

  I think the best solution is to just upgrade to glibc-2.9's nscd code,
which works much better - we will be doing that within a maintenance
update for OpenSUSE 11.0:


  Even in glibc-2.9, there is still an open race between gc() and adding
to the cache, as described in:


This still leads to occassional crashes, but much less frequent than
in glibc-2.8 and should be fixed soon.

  SUSE does enable nscd by default - I have been unable to look into
these issues before, but we are very careful to have rock-solid stable
nscd in our upcoming SLES11. In the longer term, we are considering to
switch to unscd for its more robust design.

				Petr "Pasky" Baudis
People who take cold baths never have rheumatism, but they have
cold baths.

More information about the Ubuntu-devel-discuss mailing list