OpenVZ Forum


Home » Mailing lists » Users » UDP traffic doesn't arrive in VPS
UDP traffic doesn't arrive in VPS [message #25264] Wed, 19 December 2007 10:53 Go to next message
Arjan Schrijver is currently offline  Arjan Schrijver
Messages: 6
Registered: November 2007
Junior Member
From: openvz.org
Hello people,

I've got a problem with my OpenVZ installation. We wanted to build a
syslog server on a VPS, but it looks like OpenVZ can't handle the UDP
traffic that arrives at the VPS.
When we have 3 or less servers logging to the VPS, everything works like
a charm. But when more (mail-) servers start logging, the UDP buffer
seems to overflow.
I looked at /proc/user_beancounters on the hardware node, and there were
no errors in the dgramrcvbuf line (or any other line). The buffer just
seems to fill until about 300000 (the limit is 1500000). The buffer
never gets above 300000, but most of the loglines don't arrive in the VPS.
Is there a limit on UDP traffic one VPS can receive?

Thanks in advance.
Regards,
Arjan
Re: UDP traffic doesn't arrive in VPS [message #25270 is a reply to message #25264] Wed, 19 December 2007 13:05 Go to previous messageGo to next message
gblond is currently offline  gblond
Messages: 64
Registered: May 2007
Member
From: openvz.org
On 19 December 2007 13:53:13 Arjan Schrijver wrote:
> Hello people,
> 
> I've got a problem with my OpenVZ installation. We wanted to build a
> syslog server on a VPS, but it looks like OpenVZ can't handle the UDP
> traffic that arrives at the VPS.
> When we have 3 or less servers logging to the VPS, everything works like
> a charm. But when more (mail-) servers start logging, the UDP buffer
> seems to overflow.
> I looked at /proc/user_beancounters on the hardware node, and there were
> no errors in the dgramrcvbuf line (or any other line). The buffer just
> seems to fill until about 300000 (the limit is 1500000). The buffer
> never gets above 300000, but most of the loglines don't arrive in the VPS.
> Is there a limit on UDP traffic one VPS can receive?

I did't hear about any limit on UDP traffic for VPS.
Can you describe your system configuration, kernel version, syslog
and related config files?

Note, that UDP doesn't support flow control, therefore some data can be lost. 

Try to change sysctl net.core.rmem_default. It parameter is used to set socket receive buffer size.


> 
> Thanks in advance.
> Regards,
> Arjan
-- 
Thank,
Vitaliy Gusev
Re: UDP traffic doesn't arrive in VPS [message #25314 is a reply to message #25264] Thu, 20 December 2007 07:05 Go to previous message
vaverin is currently offline  vaverin
Messages: 688
Registered: September 2005
Senior Member
From: *sw.ru
Hi Arjan,

IMHO it makes sense to check traffic by tcpdump: on the host server's external interface and on internal venet interface, and then on venet inside VE.

thank you,
Vasily Averin
Previous Topic: ALERT! /dev/mapper/ubuntu-root does not exist
Next Topic: Live Migration Fails
Goto Forum:
  


Current Time: Sun Jul 21 14:48:27 GMT 2019