Hi,
Thanks for the responses.
I totally agree that the session initiation and maintainance is the
responsibility of the operating system. This Centos 6.0 system is fully
up-to-date with patches from one month ago.
I tested stopping iptables (had some weird ftp troubles some time ago
which solved by restarting iptables), but with no luck, I also tested
the settings Joe Gooch suggested. Unfortunately no luck there.
Euhm... all this suddenly, the upload succeeds.. I did test some
settings, but all changes are reverted.. Hm, how am i going to explain
this to the customer...
------------------------------------------------------------------------
Met vriendelijke groet,
Marcus Smit
MSDirect Internet Diensten
www.msdirect.nl <http://www.msdirect.nl>
Mobiel: 06 - 167 20 817
Op 16-12-2011 19:27, Joe Gooch schreef:
Options on linux that have resolved network issues for me in the past:
echo 0 > /proc/sys/net/ipv4/tcp_timestamps
echo 0 > /proc/sys/net/ipv4/tcp_ecn
If they work you will want to use sysctl.conf to make them permanent,
i.e.:
net.ipv4.tcp_timestamps=0
net.ipv4.tcp_ecn=0
Other tuning here
http://www.bloke.com/linux/kernel/network.html
YMMV!
Joe
*From:*Jacob Anderson [mailto:[email protected]]
*Sent:* Friday, December 16, 2011 11:37 AM
*To:* [email protected]
*Subject:* RE: [Pound Mailing List] Upload problem through Pound
Hello,
The FIN/ACK is a TCP stack related issue, not pound. Do you have the
most recent patches and such for your host server?
I’ve seen this same behavior for a variety of hosts, not just Windows
clients. Plus, I’ve seen this on CentOS 4 and CentOS 5, and so far no
relief in the way of a TCP protocol bug fix.
Do you have iptables running or any other software firewall on the
pound host? I have had iptables running on all of the boxes that host
pound with this error. I have not tried disabling iptables to see if
it clears.
-- jake
*From:*MSDirect Internet Diensten - Support [mailto:[email protected]]
*Sent:* Friday, December 16, 2011 2:48 AM
*To:* [email protected] <mailto:[email protected]>
*Subject:* Re: [Pound Mailing List] Upload problem through Pound
Hi,
This is an example config for a site that needs uploads:
Service "94.124.89.211_80__wepaintyou.massmovement.nl"
HeadRequire "Host: wepaintyou.massmovement.nl"
BackEnd
Address 91.199.219.83
Port 80
Priority 5
Timeout 300
End
End
Is it possible that "Timeout 300" is only used for the connection
itself but individual requests have a different timeout ? Also,
please note that uploads using Flash-sites nearly everytime succeed
and it seems that https-uploads succeed as well...
According to the docs the Timeout is the time pound waits for the
*response* from the backend. This should start counting as soon your
request (upload) is completed.
Did you watch the connection using tcpdump? Does the data stop flowing?
Does pound kill the connection, regardless receiving data from the
client?
In the attachement you will find the tcp stream for the POST request.
As i see it, this is just a plan POST request that is reset with a
FIN/ACK. But why the RST's ? The site went to production so i could
not test it as it was but instead i had to create an extra alias as
you can see in the dump (marcustest.massmovement.nl). Points to the
same virtualhost in Apache.
I hope someone can help me solving this problem.
I think i reduced the problem to two possible bugs in either Windows7
or Pound.
In a session that fails, i see a retransmission (by Windows) for a
packet that already was ACKed. Ofcourse, this packet is not ACKed
again, which for Windows is enough reason to close the session, making
the fileupload fail. See the attached file for more info.
As you can see in packet 12 an ACK is sent for 8281, but the Windows 7
workstation retransmits the packet in packet 13. Nothing happens for
10 seconds, so Pound (or Linux, not sure) cleans up.
------------------------------------------------------------------------
Met vriendelijke groet,
Marcus Smit
MSDirect Internet Diensten
www.msdirect.nl <http://www.msdirect.nl>
Mobiel: 06 - 167 20 817
