On Thu, Dec 13, 2018 at 7:24 PM Ivan Kelly <iv...@apache.org> wrote: > > I don't fully understand how the cluster-wide version work here, > specially > > how do clients react when people use the tool to bump the version in > ledger > > layout. > > Clients don't have to react immediately. The cluster-wide setting is > the max _allowable_ format version. When it gets bumped, for example > from 2 to 3, clients that started when the value was 2 can continue to > write metadata in format 2, and all clients will will be able to read > it. Clients start after the bump can start to write in format 3. There > is currently nothing to motivate moving to version 3, but when we do > add something to the metadata protobuf, we will be able to have > clients read all the fields (even if it doesn't recognise it all). > > > IMO a client setting is probably good enough and more flexible for people > > to control the upgrade stories and there will no surprises, since the > > version is controlled by the bookkeeper "writers". > > I don't have a strong opinion either way. Client conf based gives more > power to users, but also requires more coordination among all users. >
I am not sure about this. If clients don't react the changes of ledger layout, the information in ledger layout is just informative, you still need to coordinate both readers and writers. so IMO the version in ledger layout is not really useful. so I would prefer using a simple configuration setting rather than storing it in ledger layout. > Clusterwide allows it to be set at a central authority, but that gives > users less freedom. Both have merits. How common is it for users from > different organisations to share ledgers? > > -Ivan >
