> < 'already got some feedback earlier on this and had this task in the > list of things > to work on... :) > > > Having the throttling start with some per-defined "degree" and then have > that "degree" gradually increase ...either > > a) automatically as shown in Juan's example above (or) > > b) via some TBD user level interface... > > ...is one way to help with ensuring convergence for all cases. > > The issue of continuing to increase this "degree" of throttling is an > obvious area of concern for the workload ( that is still trying to run > in the VM). Would it it better to force the live migration to switch > from the iterative pre-copy phase to the "downtime" phase ...if it fails > to converge even after throttling it for a couple of iterations ? Doing > so could result in a longer actual downtime. Hope to try this and > see... but if anyone has inputs(other than doing post-copy etc) pl. do > share. > > > > > > BTW, you are testing this with any workload to see that it improves? > > Yes. Please do share some data. > > > > > > >> + mig_throttle_on = true; > >> + } > > Vinod, what do you think? > As is noted in the current code...the "logic" to detect the lack of > convergence needs to be refined. If there is a better way to help detect > same (and which covers these other cases like XBZRLE etc) then I am all > for it. I do agree with Juan about the choice of magic numbers (i.e. > one may not be better than the other). > > BTW, on a related note... > > I haven't used XBZRLE in the recent past (after having tried it in the > early days). Does it now perform well with larger sized VMs running real > world workloads ? Assume that is where you found that there was still > need for forcing convergence ? > > Pl. do consider sharing some results about the type of workload and also > the size of the VMs etc that you have tried with XBZRLE. > > > Do you have a workload to test this? > > Hmm... One can test this with memory intensive Java warehouse type of > workloads (besides using synthetic workloads). > > Vinod > It will be more robust no matter whether xbzrle is enable. This patch don't aim at performance. BTW, the migration transfer speed which used in migration_thread also has same problem. I want to fix it, do you have any suggestion? Thanks.
> > Thanks, Juan. > > . > > Best regards, -Gonglei
