Which changes break compatibility in the 0.10.1 branch? It would be good to fix before the release goes out.
Ismael On 29 Nov 2016 9:09 pm, "Ignacio Solis" <iso...@igso.net> wrote: > Some of the changes in the 0.10.1 branch already are not bug fixes. Some > break compatibility. > > Having said that, at this level we should maintain a stable API and leave > any changes for real version bumps. This should be only a bugfix release. > > Nacho > > > > > On Tue, Nov 29, 2016 at 8:35 AM, Ismael Juma <ism...@juma.me.uk> wrote: > > > I disagree, but let's discuss it another time and in a separate thread. > :) > > > > Ismael > > > > On Tue, Nov 29, 2016 at 4:30 PM, radai <radai.rosenbl...@gmail.com> > wrote: > > > > > designing kafka code for stable extensibility is a worthy and noble > > cause. > > > however, seeing as there are no such derivatives out in the wild yet i > > > think investing the effort right now is a bit premature from kafka's > pov. > > > I think its enough simply not to purposefully prevent such extensions. > > > > > > On Tue, Nov 29, 2016 at 4:05 AM, Ismael Juma <ism...@juma.me.uk> > wrote: > > > > > > > On Sat, Nov 26, 2016 at 11:08 PM, radai <radai.rosenbl...@gmail.com> > > > > wrote: > > > > > > > > > "compatibility guarantees that are expected by people who subclass > > > these > > > > > classes" > > > > > > > > > > sorry if this is not the best thread for this discussion, but I > just > > > > wanted > > > > > to pop in and say that since any subclassing of these will > obviously > > > not > > > > be > > > > > done within the kafka codebase - what guarantees are needed? > > > > > > > > > > > > > I elaborated a little in my other message in this thread. A simple > and > > > > somewhat contrived example: `ConsumerRecord.toString` calls the > `topic` > > > > method. Someone overrides the `topic` method and it all works as > > > expected. > > > > In a subsequent release, we change `toString` to use the field > directly > > > > (like it's done for other fields like `key` and `value`) and it will > > > break > > > > `toString` for this user. One may wonder: why would one override a > > method > > > > like `topic`? That is a good question, but part of the exercise is > > > deciding > > > > how we approach these issues. We could make the methods final and > > > eliminate > > > > the possibility, we could document it so that users can choose to do > > > weird > > > > things if they want, etc. > > > > > > > > Another thing that is usually good to think about is the expectation > > for > > > > `equals` and `hashCode`. What if subclasses implement them to have > > value > > > > semantics instead of identity semantics. Is that OK or would it break > > > > things? > > > > > > > > Designing for implementation inheritance is generally complex > although > > > for > > > > simple "record" like classes, it can be easier by following a few > > > > guidelines. > > > > > > > > Ismael > > > > > > > > > > > > > -- > Nacho - Ignacio Solis - iso...@igso.net >
