[Samba] samba AD DC eats memory

[Andrew Bartlett]

Thanks!

I've got a fix for one issue seen here.

I'd love to credit you with a fix.  Please let me know what name and
any affiliation (eg company) you would like listed.

There will probably be more to come, and if you can try and get me the
report for any other large processes that would be awesome. 

See

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14299

MR: https://gitlab.com/samba-team/samba/-/merge_requests/1168

Andrew Bartlett

On Wed, 2020-02-26 at 14:15 +0300, Alex wrote:
> Tweaking timeout value did the trick:

(log files removed)

> Please, let me know if you still need me to run samba under valgrind
> 
> > > > If you can't, then please use 'samba-tool processes' to line up
> > > > pids
> > > > with names.
> > > 
> > > [root at vm-dc3 var]# samba-tool processes
> > >  Service:                          PID
> > > --------------------------------------
> > > cldap_server                      1529
> > > dnssrv                            1555
> > > dnsupdate                         1553
> > > kccsrv                            1548
> > > kdc_server                        1533
> > > kdc_server(worker 3)              1552
> > > kdc_server(worker 0)              1540
> > > kdc_server(worker 1)              1544
> > > kdc_server(worker 2)              1549
> > > ldap_server                       1525
> > > ldap_server(worker 1)             1569
> > > ldap_server(worker 2)             1571
> > > ldap_server(worker 0)             1567
> > > ldap_server(worker 3)             1573
> > > nbt_server                        1517
> > > notify-daemon                     1563
> > > rpc_server                        1514
> > > rpc_server(worker 2)              1528
> > > rpc_server(worker 0)              1520
> > > rpc_server(worker 1)              1524
> > > rpc_server(worker 3)              1532
> > > samba                             1508
> > > winbind_server                    1547
> > > 
> > > > 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?
> > > 
> > > sorted by swap: https://paste.ee/p/w6TL5
> > > 
> > > I tried to grab pool-usage for PIDs 1540, 1552 and 1555 and got
> > > "No
> > > replies
> > > received" for each of them.
> > > 
> > > sorted by rss: https://paste.ee/p/Rjsgw
> > > 
> > > pool-usage for the PID 1520 returns the same "no replies"
> > > 
> > > Let me know if you need anything else.
> > It looks to me that the worst of the issue in the KDC.
> > You could run Samba under valgrind:
> > PYMALLOC=malloc valgrind --trace-children=yes bin/samba -i
> > You could also try giving that pool-usage longer to run with the --
> > timeout option to smbcontrol, as the default timeout is 10 seconds.
> > smbcontrol --timeout 60 ...
> 
> 
-- 
Andrew Bartlett
https://samba.org/~abartlet/
Authentication Developer, Samba Team         https://samba.org
Samba Development and Support, Catalyst IT - Expert Open Source
Solutions
https://catalyst.net.nz/services/samba