[Samba] dcesrv process purpose

[Francesco Malvezzi]

>> hi all,
>> 
>> after investigating a bit more about my performance problems, the task
>> that spins at 100% cpu (once in a while) appears to be consistently dcesrv.
>> 
>> What is the dcesrv role's purpose?
>> 
>> Which is the samba log facility that captures dcesrv activities?
>> 
>> thank you,
> 
> Can you be a bit more specific about the exact process name causing you
> trouble?  
> 

from top I see the process with PID 1648 is the hungry one (today), then
I did:

$ ps auxwww | grep 1468
root      1468  5.3 12.3 2536300 1007424 ?     R    set01 247:17 samba:
task[dcesrv]


> DCE/RPC is at the core of Samba's capability as an AD DC, covering
> important protocols like NETLOGON (NTLM auth), LSA (name/SID lookups,
> trust handling), SAMR (user administration) and DRSUAPI (replication).
>
> Additionally, there is the similarly named dreplsrv sub-process which
> handles the 'client' side of replication, pulling and pushing changes
> as required to other DCs.

thank you, really helpful.

> Finally, I would say that 50k users is not a mid-sided domain for Samba
> as an AD DC, indeed it is one of the largest I've heard of.  If so, it
> is quite likely that you are hitting some scaling issues.

the users are syncronized from OpenLDAP with LSC. When we make the
nightly full-syncronization, with hundreds of modify/add/delete, the
load is high, but not scaring. So the general case is, in my opinion, fine.

> 
> We continue to improve Samba's AD DC performance at this scale, but
> while we have also identified a number of potential improvements we
> haven't had the opportunity to action those yet[1].
> 
> Thanks,
> 
> Andrew Bartlett
> 
> [1] Help financing Samba at scale most welcome.

took a note, thank you,

franz