Bug#513635: nscd: uses 100% CPU

[Nicolas Boullis <nboullis@debian.org>]

Package: nscd
Version: 2.7-18
Severity: important

Hi,

I just upgraded nscd from version 2.3.6.ds1-13etch8 to 2.7-18 and it 
started using 100% CPU. In fact it starts using 100% CPU a few seconds 
after it was started.

I tried to run it in debug mode (nscd -d), and it also starts using 100% 
CPU after a few seconds, without logging any activity. Note that is 
answers questions anyway, and log its activity fine.

Running top with threads shown shows several nscd threads that use 
together 100% CPU:
 4335 root      20   0  112m 2272 1716 R 11.2  0.2   0:19.02 nscd               
 4338 root      20   0  112m 2272 1716 R 11.2  0.2   0:03.04 nscd               
 4339 root      20   0  112m 2272 1716 R 11.2  0.2   0:43.08 nscd               
 4332 root      20   0  112m 2272 1716 R 10.6  0.2   1:12.14 nscd               
 4333 root      20   0  112m 2272 1716 R 10.6  0.2   1:12.18 nscd               
 4334 root      20   0  112m 2272 1716 R 10.6  0.2   1:17.18 nscd               
 4336 root      20   0  112m 2272 1716 R 10.6  0.2   0:26.56 nscd               
 4337 root      20   0  112m 2272 1716 R 10.6  0.2   0:44.26 nscd               
 4381 root      20   0  112m 2272 1716 R 10.6  0.2   0:00.88 nscd               

(The number of crazy nscd threads keeps increasing with time.)

This finally makes my system unusable while nscd is running, so I have 
to stop it.

This would certainly deserve grave severity if it affected everyone, but 
I can't believe it does and nobody reported the proble earlier. Hence, 
there must be something specific to my system. The problem might for 
example be powerpc-specific...

FWIW, whenever I start it in debug mode, it first prints:
4244: invalid persistent database file "/var/cache/nscd/passwd": file size does not match
4244: invalid persistent database file "/var/cache/nscd/group": file size does not match
4244: invalid persistent database file "/var/cache/nscd/services": file size does not match

If I remove those cache files, it does not print this, but does again 
the next time I start it.


Cheers,

Nicolas

-- System Information:
Debian Release: 5.0
  APT prefers testing
  APT policy: (800, 'testing'), (700, 'unstable'), (600, 'experimental')
Architecture: powerpc (ppc)

Kernel: Linux 2.6.23-irma (PREEMPT)
Locale: LANG=C, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages nscd depends on:
ii  libc6                         2.7-18     GNU C Library: Shared libraries

nscd recommends no packages.

nscd suggests no packages.

-- no debconf information