Quoting btinsley <btins...@gmail.com>: > Hi list, > > Has anyone experienced packet loss issues on real servers in an LVS/DR > configuration? I don't believe this is an LVS issue per se, but I am > curious if anyone else has experienced the same problem. > > What I am seeing is packets are being forwarded from the director to the > real server, but once they arrive at the real server there is packets > loss such that it totally breaks communication with the client (at the > TCP level). It seems to be fairly specific to loosing delayed ACKs. I > see this reflected in the /proc/net/netstat statistics on the client > (DelayedACKLost and TCPDSACKOldSent) and in a side-by-side comparison of > tcpdump captures on the real server's receiving interface (bond1) and > transmitting interface (bond0). The dummy0 interface is configured with > the VIP on the real server and I have tried using the loopback interface > with the same result. We have been using this same configuration for > several years, so I am certain that there are no incorrect sysctl values > (e.g., arp_announce, arp_ignore, etc) and there is no interference from > netfilter. > > This was first noticed on the SLES11 SP1 kernel, which is based on > 2.6.32. In the process of gathering information to open a case with the > vendor, I found that the same problem occurrs on the kernel.org > 2.6.32.28 version. Further testing revealed that the issue was > reproducible on all kernel.org versions (2.6.[32-36]) up to stable > 2.6.37, when it no longer happens. It also works on the SLES11 SP0 > kernel, which is 2.6.27 based. I have looked through the git changelogs > for the kernel across all versions and there do no seem to be any > changes that would indicate why this is happening, but I don't claim to > be an expert here. I have also searched the LVS mailing list archives in > some depth and found nothing. > > If anyone has had a similar experience, I would appreciate any > information you may be able to share.
Yes--I've seen it with the lvs bundled with RHEL4 and 5 DR, and it seems to particularly anger connections from Windows 7 SSL/TLS clients. I'll give .37 a shot and let you know what I see! cc _______________________________________________ Please read the documentation before posting - it's available at: http://www.linuxvirtualserver.org/ LinuxVirtualServer.org mailing list - lvs-users@LinuxVirtualServer.org Send requests to lvs-users-requ...@linuxvirtualserver.org or go to http://lists.graemef.net/mailman/listinfo/lvs-users
