On Wed, May 8, 2019 at 6:12 AM zengran zhang <z13121369189@xxxxxxxxx> wrote: > > Hi Sage: > > I see there are two difference between luminous and upstream after > the patch of *fast dispatch peering events* > > 1. When handle pg query w/o pg, luminous will preject history since > the epoch_send in query and create pg if within the same interval. > but upstream now will reply empty info or log directly w/o create the pg. > My question is : can we do this on luminous? I think you mean "project history" here? In any case, lots of things around PG creation happened since Luminous, as part of the fast dispatch and enabling PG merge. That included changes to the monitor<->OSD interactions that are difficult to do within a release stream since they change the protocol. We typically handle those protocol changes by flagging them on the "min_osd_release" option. We probably can't backport this behavior given that. > > 2. When handle pg notify w/o pg, luminous will preject history since > the epoch_send of notify and give up next creating if not within the > same interval. > but upstream now will create the pg unconditionally, If it was > stray, auth primary will purge it later. > Here my question is: is the behavior of upstream a specially > designed improvement? My recollection is that this was just for expediency within the fast dispatch pipeline rather than something we thought made life within the cluster better, but I don't remember with any certainty. It might also have improved resiliency of PG create messages from the monitors since the OSD has the PG and will send notifies to subsequent primary targets? -Greg
