On Wed, Aug 27, 2008 at 05:24:53PM +0200, Julius Volz wrote: > On Wed, Aug 27, 2008 at 8:09 AM, Simon Horman <horms@xxxxxxxxxxxx> wrote: > > On Fri, Aug 22, 2008 at 02:14:11PM +0200, Julius Volz wrote: > >> On Fri, Aug 22, 2008 at 1:23 PM, Sven Wegener <sven.wegener@xxxxxxxxxxx> wrote: > >> >> He :) Imagine an old kernel on the backup receiving new messages and > >> >> not understanding them. How could we at least handle that situation > >> >> gracefully (without totally confusing the older kernel)? We'd need to > >> >> do it in a way that old features are still communicated in the same > >> >> way. E.g., v4-only connection syncs still use the same message format, > >> >> but once you use v6 entries, an unused flag or the 'reserved' field in > >> >> ip_vs_sync_conn is used. A v6 message would still confuse an older > >> >> kernel then, but a user would already notice that ipvsadm can't > >> >> configure the v6 services on the older kernel, so that's not too bad. > >> > > >> > If that's a problem, we can easily change the communication port and even > >> > completely redesign the protocol this way, without having old kernels > >> > getting confused about the data they get. We might lose the ability to > >> > sync between different versions, but in the end this is just the > >> > connection synchronziation and both systems should be running the same > >> > version. We could also keep the old communication port for some time, if > >> > that's really needed. > >> > >> Yes, starting from scratch on another port sounds like a good idea. > >> Losing sync ability totally isn't as bad as confusing an older kernel > >> with new messages, so I hope it's not necessary to keep the old > >> baggage around? > > > > That does sound like a nice idea. I think that is important that we don't > > confuse older kernels. I guess the only time that ineroperability would be > > important is when upgrading kernels, where you might want to take the > > master ldirector down to upgrade it, then the standby. > > Good, that makes two votes for not keeping the old protocol in parallel? ;) I'd like to keep compatibility if possible. But I think there is a treshold of pain that we shouldn't cross. > >> Is there enough motivation for doing this though before having a > >> cleaned-up minimal v6 version without the sync daemon? This is where > >> I'm currently a bit stuck with... any help is appreciated :) > > > > IPv6 without sync is fine by me. Its certainly much better than no IPv6. > > Lets tackle sync a bit later. > > Ok, going for cleaning up and reworking more of the current IPv6 code then... :-) -- To unsubscribe from this list: send the line "unsubscribe lvs-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
