These are excellent points, thanks. -Jay
On Thu, Jun 14, 2012 at 1:39 PM, Evan Chan <e...@ooyala.com> wrote: > I would like to throw in a couple use cases: > > > - Allow the new consumer to reset its offset to either the current > largest or smallest. This would be a great way to restart a process that > has fallen behind. The only way I know how to do this today, with the > high-level consumer, is to delete the ZK nodes manually and restart the > consumer. > - Allow the consumer to reset its offset to some arbitrary value, and > then write that offset into ZK. Kind of like the first case, but would > make rewinding/replays much easier. > > Modularity (the ability to layer the ZK infrastructure on top of the simple > interface) would be great. > > thanks, > Evan > > > On Tue, Jun 12, 2012 at 9:59 AM, Jay Kreps <jay.kr...@gmail.com> wrote: > > > This is a great summary Neha. It would be good to get people's feedback > on > > this since we don't want to keep breaking api and > > protocol compatibility here, so the hope is to really get it right this > > time now that we have really seen all the use cases and live with the > > output for a while. I think the consumer design is a pretty hard protocol > > and API design problem, so its fun to think about. > > > > If I were to summarize Neha's requirements list, I think there are three > > high-level goals: > > > > 1. Simplify the consumer protocol to enable ease of development of > > consumer clients in other languages > > 2. Try to replace the "simple consumer" and "high level consumer" with > a > > single, general interface that has all the advantages of both. > > 3. Support a bunch of use cases that either we didn't think of, or that > > weren't possible in the partitioning model of the pre-0.8 code base. > > > > -Jay > > > > > > On Mon, Jun 11, 2012 at 4:52 PM, Neha Narkhede <neha.narkh...@gmail.com > > >wrote: > > > > > Hi, > > > > > > Over the past few months, we've received quite a lot of feedback on the > > > consumer side features and design. Some of them are improvements to the > > > current consumer design and some are simply new feature/API requests. I > > > have attempted to write up the requirements that I've heard on this > wiki > > - > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/Consumer+Client+Re-Design > > > > > > This would involve some significant changes to the consumer APIs, so we > > > would like to collect feedback on the proposal from our community. > Since > > > the list of changes is not small, we would like to understand if some > > > features are preferred over others, and more importantly, if some > > features > > > are not required at all. > > > > > > Since some part of this proposal is experimental and the consumer side > > > changes are non-trivial, we would like this initiative to not interfere > > > with the forthcoming replication release. However, it will be good to > > have > > > people from the community give this some thought and help out with the > > > JIRAs if interested. One way of managing this project could be > creating a > > > separate branch from the kafka trunk and continue development on it. > Once > > > it is ready and in good shape, we can think about cutting another > release > > > (after 0.8) for the releasing the new consumer API. Do people have > > > preferences/concerns regarding creating a separate branch for this > > project > > > ? > > > > > > Please feel free to start a discussion on this JIRA - > > > https://issues.apache.org/jira/browse/KAFKA-364 > > > > > > Thanks, > > > > > > Neha > > > > > > > > > -- > -- > *Evan Chan* > Senior Software Engineer | > e...@ooyala.com | (650) 996-4600 > www.ooyala.com | blog <http://www.ooyala.com/blog> | > @ooyala<http://www.twitter.com/ooyala> >
