facing very slow authentication responses from samba4, urget help needed

Matthieu Patou mat at samba.org
Mon May 21 11:25:28 MDT 2012

Hello Andreas,
>> Hello Matthieu,
>> with your help I was able to find one cause of the problem. It seems
>> that my postfix configuration is faulty. When sending a mail several
>> different ldap queries are sent to the samba server. This has not been
>> an issue when using the Windows DC as it could handle the requests much
>> faster than the samba4 server. These queries seem to put a lot of stress
>> to the samba processes, as the CPU utilization gets about 100% in those
>> situations (2cores>3Ghz).
> Well part of the reason is that the LDAP is only done by one process 
> at most so you can only saturate 1 core, where I suppose that MS AD DC 
> are able to split in multiple threads.
> Please also note that we have plans to improve the speed of Samba we 
> definitely know that we are not very good in some area in the AD 
> database.
> I would be interested if you could share the query that were faulty in 
> the long run it can be instructive to see what we can do to solve this.
>> I will try to fix my postfix configuration to
>> remove the useless LDAP queries.
> Matthieu.
I'm still interested about this, I would be really interested to have 
exemple of slow query in real production environment.

If you are concerned about privacy, please email me directly.


Matthieu Patou
Samba Team

More information about the samba-technical mailing list