Hello, On 2012-08-24 17:14, David Coulson wrote: > > On 8/24/12 8:53 AM, Dmitry Akindinov wrote: >> >> So, again, routing is fine, the traffic does go as it should (to the >> new balancer and then to the old one, as a part of the "real server >> pool" or "farm"). The problem is that ipvs software on the "old" >> balancer drops some of the packets when it is running the sync daemon. >> As soon as the sync daemon is stopped, the problem disappears. > Sorry, I totally missed that your IPVS boxes are also your 'real' > servers - I had an issue like that a while ago. Basically as far as I > can tell, if there is a connection in the sync table, the kernel will > use it even if you don't have ipvs rules entered, or even if you are > using fwm and you don't have an applicable iptables rule. > > Someone who knows the internals of ipvs better can probably get more > specific, but I was unable to find a workaround for it that did not > involve disabling the sync daemon. > > On my end, I either changed my scheduler to SH and stopped using the > sync daemon, or separated the ipvs and real servers into separate > systems to avoid the issue altogether.
We are trying to make ipvs balancing a part of our product and would rather avoid requiring additional nodes for our cluster. Actually, there is one more observation: as soon as the a first "troubled" connection is established, the Linux kernel thread ksoftirqd starts to consume 100% of CPU, and as new connections come in, more ksoftirqd threads appear in the "top" output, all looping somewhere - 100% CPU utlization, till all 8 CPUs on that server are consumed by them. It looks like a real bug in the ipvs software - we hav most probably to move this discussion to the lvs-devel list... -- Best regards, Dmitry Akindinov _______________________________________________ Please read the documentation before posting - it's available at: http://www.linuxvirtualserver.org/ LinuxVirtualServer.org mailing list - [email protected] Send requests to [email protected] or go to http://lists.graemef.net/mailman/listinfo/lvs-users
