samba - Nov 2016 - 80k+ locked files from single samba user

Hi,

our setup succesfully serves 100+ concurrent users for years.

beginning a month ago every few days we see single users with 80k+ locked files.
Normally all users together only have <5k locked files.

This large amount of locked files degrades server performance (too much consumed
memory, server beginns swapping).

Is there any way i can prevent single users to lock more than for example 500
files?


thanks + best regards

dirk

On Thu, Nov 17, 2016 at 02:26:48PM +0100, Dirk Wartmann via samba
wrote:
> Hi,
> 
> our setup succesfully serves 100+ concurrent users for years.
> 
> beginning a month ago every few days we see single users with 80k+ locked
files. Normally all users together only have <5k locked files.
> 
> This large amount of locked files degrades server performance (too much
consumed memory, server beginns swapping).
> 
> Is there any way i can prevent single users to lock more than for example
500 files?
Better to find the root cause. What changed a month ago ?

> Gesendet: Donnerstag, 17. November 2016 um 20:47 Uhr
> Von: "Jeremy Allison via samba" <samba at lists.samba.org>
> An: "Dirk Wartmann" <dirk.wartmann at gmx.de>
> Cc: samba <samba at lists.samba.org>
> Betreff: Re: [Samba] 80k+ locked files from single samba user
>
> On Thu, Nov 17, 2016 at 02:26:48PM +0100, Dirk Wartmann via samba wrote:
> > Hi,
> > 
> > our setup succesfully serves 100+ concurrent users for years.
> > 
> > beginning a month ago every few days we see single users with 80k+
locked files. Normally all users together only have <5k locked files.
> > 
> > This large amount of locked files degrades server performance (too
much consumed memory, server beginns swapping).
> > 
> > Is there any way i can prevent single users to lock more than for
example 500 files?
> 
> Better to find the root cause. What changed a month ago ?
> 
Nothing changed on the server side, no patches installed etc. 

As i suspect the clients to trigger the problem, i hope there is a way to
strenghten the server against such a denial of service like scenario ...