On Tue, Apr 12, 2016 at 11:03:47AM +1000, jupiter wrote:
> Hi,
>
> We are running sssd version 1.12.4-47 on CentOS 6. It works fine in
> general, but from time to time, some nodes listed all user ids with
> "nobody",
Was this problem happening only on an NFS share..?
> calling id username immediatly returned "No such user",
Hmm, I guess not, this sounds like a generic issue, if neither id
couldn't find the user.
> it looks
> the id went to cache and did not contact to the LDAP.
Please note that if the user was looked up at least once before, then
even if SSSD couldn't contact the server for one reason or another, it
should have returned entries from the cache.
>
> On one occasion, I added debug_level = 6 to the sssd.conf, restarted sssd,
> the "nobody" was gone and id username was returned correct LDAP user id. It
> did not make any sense to me how adding a debug_level could fix the
> problem.
I suspect it was actually the restart, because the restart might cause
sssd to reconnect to servers and operate online.
What you can do, if for some reason running with debugging enabled all
the time is not practical, is use the sss_debuglevel tool to bump
debugging on the fly.
But at any rate, we need to see the sssd logs to proceed.
> I could smell the issue from sssd cache, but I have no idea since
> the all default cache setting only for some seconds, but when the node
> caught in that problem, it can sit for many days with uids in nobody, id
> returns no such user.
>
> After searching from Internet, someone suggested to run sss_cache -E to
> invalidate all cached entries would solve the problem, I tried, it did not
> work.
Well, if sssd was offline at that time, then invalidating the cache
wouldn't help, because sssd wouldn't have a way to fetch the data from..