facing very slow authentication responses from samba4, urget help needed

[Andrew Bartlett]

On Sat, 2012-05-12 at 08:42 +0200, Andreas Oster wrote:
> Am 11.05.2012 15:34, schrieb Andrew Bartlett:
> > On Fri, 2012-05-11 at 11:57 +0200, Andreas Oster wrote:
> >> Am 11.05.2012 10:43, schrieb Matthieu Patou:
> >>> On 05/10/2012 11:41 PM, Andreas Oster wrote:
> >>>> Hello list,
> >>>>
> >>>> I have migrated our Windows AD to a samba4/bind9_dlz environment and are
> >>>> now facing high latencies for user/password authentications, especially
> >>>> apparent when doing LDAP authentication and group lookups from postfix
> >>>> or dovecot.
> >>> How many users in your setup ?
> >>>> But also the authentication from our file servers, running
> >>>> samba3 + winbind, is very slow. When accessing a share for the first
> >>>> time or after some inactivity it takes quite a while till folder view
> >>>> pops up.
> >>> Well there is nothing special in your setup it looks like the one I was
> >>> using, and auth was ok.
> >>>
> >>> But I had ~ 30 users in production.
> >>>
> >>> Matthieu.
> >>>
> >>>
> >> Hello Matthieu,
> >>
> >> thanks for the fat reply.
> >>
> >> We have about the same user number.I have migrated our old win2000 AD to
> >> samba4 and raised forest and domain level to 2008r2. In my test (esx)
> >> environment I have only tested with some clients (WinXP, WinVista, 2k8
> >> server) and it seemed to work well, at least authentication, GPOs and
> >> sripts did work like before. I did not recognize such delays in my
> >> testing environment. Unfortunately I did not test the LDAP stuff.
> >>
> >> Any idea how to find out where the delay is generated ? What I have
> >> observed is that sometimes the samba processes use up a lot of CPU.
> > 
> > Two approaches come to mind:
> > 
> > - Use the perf tools
> > https://code.google.com/p/kernel/wiki/PerfUserGuide
> > 
> > - See if you happen to hit the spinner with:
> >   gdb -p <samba pid>
> >   bt full
> >   c
> >   (Ctrl-C)
> >   bt full
> >   c
> > 
> Hello Andrew,
> 
> I will try to follow your two proposed approaches. Unfortunately I have
> never used the perf tools before, can you give me some more hints how to
> use those in my case ?

See the URL, but eg

perf record samba -i -M single 
(do authentication, then Ctrl-C)
perf report

Andrew Bartlett

-- 
Andrew Bartlett                                http://samba.org/~abartlet/
Authentication Developer, Samba Team           http://samba.org