[Samba] samba AD DC eats memory

[Andrew Bartlett]

G'Day,

Can you rebuild Samba with libbsd so we get better process titles?

If you can't, then please use 'samba-tool processes' to line up pids
with names.

Then, please run the smbcontrol not against 'all' (which hasn't got all
the processes, clearly only returned data from eight), but against each
of the largest processes individually, and put them in distinct files
for me?

If you can run Samba 4.12rc we will give some better info in that pool-
usage output.  

I've written a patch to improve our process titles further, in the
future you will be able to use 'ps -ef -o pid,comm' and get some idea
what each process is, without the rebuild (on linux):

https://gitlab.com/samba-team/samba/-/merge_requests/1154

Andrew Bartlett

On Fri, 2020-02-21 at 19:27 +0300, Alex via samba wrote:
> Guys,  I still need help with this. After a week of uptime almost all
> swap space
> is taken:
> top - 19:24:32 up 7 days,  5:26,  1 user,  load average: 0.24, 0.16,
> 0.22
> Tasks: 169 total,   1 running, 168 sleeping,   0 stopped,   0 zombie
> %Cpu(s):  0.2 us,  0.2 sy,  0.0 ni, 99.7 id,  0.0 wa,  0.0 hi,  0.0
> si,  0.0 st
> KiB Mem :  1794860 total,   202308 free,  1458900 used,   133652
> buff/cache
> KiB Swap:  1048572 total,   147568 free,   901004 used.   194116
> avail Mem
> 
> Current "ps auxw" along with "smbcontrol all pool-usage" are here:
> https://paste.ee/p/P3doR
> 
https://www.dropbox.com/s/76qdq1x89brmib0/samba.all.pool-usage.txt.gz?dl=0
> 
> Any help is kindly appreciated!
> 
> > > On Mon, 2020-02-17 at 19:11 +0300, Alex via samba wrote:
> > > > I'm running Samba AD DC in a VM under Proxmox. And it's eaten
> > > > all RAM (1.8GB) within 3
> > > > days of running:
> > > Exactly which version is this?
> > Sorry, forgot to mention it. Samba version is 4.11.6. Some more
> > info (if needed):
> > [root at vm-dc3 ~]# wbinfo -u | wc -l
> > 62
> > [root at vm-dc3 ~]# wbinfo -g | wc -l
> > 78
> > > Which sub-process is eating the memory?
> > I was trying to determine that w/o success. Looks like all Samba
> > processes do
> > that.
> > > Can you get a talloc dump using 'smbcontrol $PID pool-usage' for
> > > whichever PID is leaking the memory?
> > Not sure which one is _leaking_ the memory, so I took the one which
> > ate memory
> > more than the others (by "ps auxw").
> > Please, find the report here:
> > 
https://www.dropbox.com/s/76qdq1x89brmib0/samba.1520.pool-usage.txt.gz?dl=0
> > > Does the problem reproduce on a current Samba 4.11?
> > Yes, it's on the latest.
> > > Our new LDAP server design is much more memory efficient,
> > > particularly
> > > if you have pathological clients that search for the whole DB and
> > > then
> > > keep the socket open.
> > I don't think we have such clients.
> 
> -- 
> Best regards,
> Alex
> 
> 
-- 
Andrew Bartlett                       https://samba.org/~abartlet/
Authentication Developer, Samba Team  https://samba.org
Samba Developer, Catalyst IT          
https://catalyst.net.nz/services/samba