Thanks, Sangjin. I'd be interested in taking a peek at a personal GitHub repo or even just a patch file of those changes. If there were incompatibilities, then that doesn't bode well for an upgrade to 2.6.
--Chris Nauroth On 5/19/15, 8:40 PM, "Sangjin Lee" <sj...@apache.org> wrote: >When we moved to Hadoop 2.4, the associated protobuf upgrade (2.4.1 -> >2.5.0) proved to be one of the bigger problems. In our case, most of our >users were using protobuf 2.4.x or earlier. > >We identified a couple of places where the backward compatibility was >broken, and patched for those issues. We've been running with that patched >version of protobuf 2.5.0 since. I can push out those changes to github or >something if others are interested FWIW. > >Regards, >Sangjin > >On Tue, May 19, 2015 at 9:59 AM, Colin P. McCabe <cmcc...@apache.org> >wrote: > >> I agree that the protobuf 2.4.1 -> 2.5.0 transition could have been >> handled a lot better by Google. Specifically, since it was an >> API-breaking upgrade, it should have been a major version bump for the >> Java library version. I also feel that removing the download links >> for the old versions of the native libraries was careless, and >> certainly burned some of our Hadoop users. >> >> However, I don't see any reason to believe that protobuf 2.6 will not >> be wire-compatible with earlier versions. Google has actually been >> pretty good about preserving wire-compatibility... just not about API >> compatibility. If we want to get a formal statement from the project, >> we can, but I would be pretty shocked if they decided to change the >> protocol in a backwards-incompatible way in a minor version release. >> >> I do think there are some potential issues for our users of bumping >> the library version in a minor Hadoop release. Until we implement >> full dependency isolation for Hadoop, there may be some disruptions to >> end-users from changing Java dependency versions. Similarly, users >> will need to install a new native protobuf library version as well. >> So I think we should bump the protobuf versions in Hadoop 3.0, but not >> in 2.x. >> >> cheers, >> Colin >> >> On Fri, May 15, 2015 at 4:55 AM, Alan Burlison >><alan.burli...@oracle.com> >> wrote: >> > On 15/05/2015 09:44, Steve Loughran wrote: >> > >> >> Now: why do you want to use a later version of protobuf.jar? Is it >> >> because "it is there"? Or is there a tangible need? >> > >> > >> > No, it's because I'm looking at this from a platform perspective: We >>have >> > other consumers of ProtoBuf beside Hadoop and we'd obviously like to >> > minimise the versions of PB that we ship, and preferably just ship the >> > latest version. The fact that PB seems to often be incompatible across >> > releases is an issue as it makes upgrading and dropping older versions >> > problematic. >> > >> > -- >> > Alan Burlison >> > -- >>
