facing very slow authentication responses from samba4, urget help needed

[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

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