to many sockets ?

[Markus Wenke <M.Wenke@web.de>]

Hi,

I wrote a program which handles incomming sockets asynchron.
It can handle up to 140000 connections simultaneously while every 
connection send some bytes in both directions continuously.

But if I want to connect more than the 140000 connection  my application 
has been killed by the oom-killer, but the System has enough memory.

If I use a patched Xen-Kernel (2.6.16.21-0.13-xen, only the kernel, no 
xend) it can handle up to 200000 connections.


Is there a kernel param, or something else to tune the kernel, that it 
can handle more Connections?

Or can I determine how many connections can my really System accept 
before the oom-killer kills my app?


please send me an email, for getting the /var/log/messages


thanks in advance

Markus Wenke

here my System:
////////////////////////////////////////////////////////////////////////////
setrlimit: RLIMIT_NOFILE = 500000

////////////////////////////////////////////////////////////////////////////
~# uname -a
Linux test1 2.6.18-bigsmp #3 SMP Wed Oct 4 15:18:40 CEST 2006 i686 
athlon i386 GNU/Linux

////////////////////////////////////////////////////////////////////////////
~# free:
             total       used       free     shared    buffers     cached
Mem:       3108372     193788    2914584          0       5520     107068
-/+ buffers/cache:      81200    3027172
Swap:      2104472          0    2104472

////////////////////////////////////////////////////////////////////////////
~ # cat /proc/cpuinfo
processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 35
model name      : Dual Core AMD Opteron(tm) Processor 170
stepping        : 2
cpu MHz         : 1000.000
cache size      : 1024 KB
physical id     : 0
siblings        : 2
core id         : 0
cpu cores       : 2
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 1
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge 
mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt
 lm 3dnowext 3dnow pni lahf_lm cmp_legacy ts fid vid ttp
bogomips        : 2011.55

processor       : 1
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 35
model name      : Dual Core AMD Opteron(tm) Processor 170
stepping        : 2
cpu MHz         : 1000.000
cache size      : 1024 KB
physical id     : 0
siblings        : 2
core id         : 1
cpu cores       : 2
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 1
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge 
mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt
 lm 3dnowext 3dnow pni lahf_lm cmp_legacy ts fid vid ttp
bogomips        : 2011.55