feedback on ldap improvement in samba 4.11

Denis Cardon dcardon at
Wed Nov 13 10:24:51 UTC 2019

Hi everyone,

I just wanted to say how impressed I was with the improvement in memory 
handling in ldap server in samba 4.11 that were announced in the changelog.

I was doing some debug on OOMKiller issues on a Samba-AD 4.9 with a 
large database in production. There are some buggy softwares that make 
queries for all users (the most peculiar one I have seen is a print 
driver...) and Samba 4.9 properly handles the query but allocate around 
2GiB RAM for the query while the client downloads the result. With a 
handfull of such queries piling up it can quickly run the server out of 

On the other hand with Samba-4.11 memory is allocated in a much more 
frugal way and it can handle hundred of such buggy queries without 
crashing (it may be slow but it does not crash). So kudos the Catalyst 
dev team for that great piece of work!

About the prefork model, the master ldap process is properly restarting 
the child process after a SIGTERM but it is not restarting after a 
SIGKILL. Is it normal?



Denis Cardon
Tranquil IT
12 avenue Jules Verne (Bat. A)
44230 Saint Sébastien sur Loire (FRANCE)
tel : +33 (0) 240 975 755

Tranquil IT recrute!
Samba install wiki for Frenchies :
WAPT, software deployment made easy :

More information about the samba-technical mailing list