Hi devs, during experiment on complete mode I realized we left some incomplete code parts on supporting aggregation for continuous mode. (shuffle & coalesce)
The work had been occurred around first half of 2018 and stopped, and no work has been done for around 2 years (so I don't expect anyone is working on this). The functionality is undocumented (as the work was only done partially) and continuous mode is experimental so I don't feel risks to get rid of the part. What do you think? If it makes sense then I'll raise a PR to get rid of the incomplete codes. Thanks, Jungtaek Lim (HeartSaVioR) ps. I'm kind of feeling the same with continuous mode itself - it has been still experimental over the 2 years, and while it lacks lots of essential things (backpressure, epoch synchronization, query progress, etc.) there's no additional major work over 1 year. We eventually have been excluded continuous mode for the new streaming feature like observable metric, streaming UI, etc. because it is on top of the feature which continuous mode lacks. Unlike incomplete code path, I'm not strongly against this, as it has been documented and someone might use the feature in production. I still think it's ideal to retire the feature smoothly. (Please chime in with the use case if someone has the production cases.) ps2. It feels like "feature branch" looks to be a thing to consider for efforts on one big feature.
