+1 for holding on the release. Off topic: we did not choose a release manager for 4.9 yet. Ivan and Sijie contributed most of the changes, but having a release Manager from SF would be awesome
Enrico Il giorno mer 19 dic 2018 alle ore 14:39 Sijie Guo <guosi...@gmail.com> ha scritto: > > On Wed, Dec 19, 2018 at 9:11 PM Ivan Kelly <iv...@apache.org> wrote: > > > > If it is client level configuration, in theory it is possible to have > > latest client create v3 ledger while bookies are still running in the older > > version right? > > > > Yes, autorecovery would likely just break in this case. > > > > > If we go with cluster level, I think using it part of LAYOUT_ZNODE is not > > clean. > > > I think we need to have a form of "cluster version number", or even > > better > > with a combination of capability/feature bit-map which can dictate > > the cluster behavior. > > > > I used the LAYOUT znode because that is what already exists. If we > > create another znode for this, /ledgers/CLUSTER for example, then, for > > consistency, the contents of the layout znode should really be moved > > into this new znode. But this creates a lot more BC issues than just > > using the LAYOUT znode. Old versions of the software ignore anything > > other than the first two lines in LAYOUT. So, it's not clean nor > > ideal, but it does work well within the constraints of BC. > > > > > I am assuming that the tool Ivan is talking about is used for existing > > clusters to update the cluster version number. > > > Otherwise the maxLedgerMetadataFormat is used only for new clusters; > > that is fine. > > > > The maxLedgerMetadataFormat is only written when writing a new LAYOUT > > node, so either during metaformat, or when using the proposed tool. > > When it is absent from the layout node, it defaults to version 2, > > which matches current behaviour. > > > > The important thing for the 4.9 release is that the client can read > > binary metadata, so that in 4.10 or 4.11, if we add a field to the > > metadata, then we are able to use it with 4.9 clients and newer. It is > > only that that point that maxLedgerMetadataFormat comes into play. > > > > So, for the sake of getting 4.9 out the door, I propose that we: > > > > > > > a. Rollback the 2 changes around max metadata format version. > > b. Pin serde to use V2 for now. > > c. Continue this discussion to find the long term solution. > > > > +1 > > > > > > -Ivan > >
