User lookups intermittently fail with nscd
Issue
When nscd is enabled and the system is heavily loaded, user lookups may intermittantly fail without tuning nscd. This can manifest as cronjobs failing:
Apr 18 00:01:01 localhost crond[25496]: User not known to the
underlying authentication module
Apr 18 00:01:01 localhost crond[25496]: CRON (mml) ERROR: failed to open PAM security session: Success
Apr 18 00:01:01 localhost crond[25496]: CRON (mml) ERROR: cannot set security context
Environment
- Red Hat Enterprise Linux 5.3
- Users authenticated via NIS
- NSCD enabled
- Heavily-loaded systems
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