[Samba] Lost performance between Samba 3.0.24 and 3.5.8 with high number of concurrent connections

[juan david]

2011/6/13 juan david <jd.alarcon at gmail.com>

> Hi,
>
> We are trying upgrade our roaming profile sever from Debian Etch to Debian
> Squeeze. That's means a upgrade from Samba 3.0.24 to Samba 3.5.8. Our
> production environment has above 600 concurrent users without problem. After
> upgrade to Samba 3.5.8, server can't manage above 200 users. With
> 'smbclient', the output is:
>
> Error [user] session setup failed: Call timed out: server did not respond
> after 20000 milliseconds
>
> We use Samba+Winbind+kerberos to validate users. After upgrade I have been
> tried all configurations that I could imagine without luck.
>
> After that I have tried simplify the problem, I made a test environment
> with the next smb.conf:
>
> [global]
>    netbios name = yela
>    security = share
>    guest account = nobody
>
> [mdrive]
>    path = /home/HUGU-Profiles/WinXP/enfgen.man
>    browseable = yes
>    public = yes
>    guest ok = yes
>
> Trivial, isn't it? The server is a Debian Squeeze with Linux Kernel
> 2.6.32-5 and Samba 3.5.8. From one client I ran the next script:
>
>  #!/bin/bash
>
> connectAndList ()
> {
>         for i in $( seq 1 1000 )
>         do
>                 fechaInicio=$( date )
>                 salida=$( smbclient //yela/mdrive -U nobody% -c ls 2>
> /dev/null )
>                 retorno=$?
>                 fechaFin=$( date )
>                 if [ ! $retorno -eq 0 ]
>                 then
>                         echo "$fechaInicio - Error $1 $salida - $fechaFin"
>                         sleep 1
>                 fi
>         done
> }
>
> for j in $( seq 1 5 )
> do
>         for i in $( seq 1 100 )
>         do
>                  connectAndList $i $j &
>         done
> done
>
> To summarize, this script do 500 concurrent connections, list the directory
> and repeat it. If one connection fail then sleep 1 second and do again.
>
> Samba 3.0.24 run script with 1 or 2 fail connection per second. In Samba
> 3.5.8 We need falling to 200 concurrent connections, in other case, the
> server was freeze and load raise over 20. There isn't any error in log. The
> server doesn't fail is the client which has return a timeout.
>
> Maybe the problem are in connection reply, because once you has been
> connect with 'smbclient' follow commands work without problem.
>
> Has Some one "Samba" with above 300 concurrent users in production
> enviroment? Does some one know something about this performance lost in
> connection time?
>
>

In your production environment How many users are there? Where is the limit?