I don't think ss now support "partitioned" watermark. and why different partition's consumption rate vary? If the handling logic is quite different, using different topic is a better way.

On Fri, Sep 1, 2017 at 4:59 PM, 张万新 <kevinzwx1992@gmail.com> wrote:
Thanks, it's true that looser watermark can guarantee more data not be dropped, but at the same time more state need to be kept.   I just consider if there is sth like kafka-partition-aware watermark in flink in SS may be a better solution.

Tathagata Das <tathagata.das1565@gmail.com>于2017年8月31日周四 上午9:13写道:
Why not set the watermark to be looser, one that works across all partitions? The main usage of watermark is to drop state. If you loosen the watermark threshold (e.g. from 1 hour to 10 hours), then you will keep more state with older data, but you are guaranteed that you will not drop important data. 

On Wed, Aug 30, 2017 at 7:41 AM, KevinZwx <kevinzwx1992@gmail.com> wrote:
Hi,

I'm working with Structured Streaming to process logs from kafka and use
watermark to handle late events. Currently the watermark is computed by (max
event time seen by the engine - late threshold), and the same watermark is
used for all partitions.

But in production environment it happens frequently that different partition
is consumed at different speed, the consumption of some partitions may be
left behind, so the newest event time in these partitions may be much
smaller than than the others'. In this case using the same watermark for all
partitions may cause heavy data loss.

So is there any way to achieve different watermark for different kafka
partition or any plan to work on this?



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