Type: New Feature
Affects Version/s: None
Fix Version/s: None
The source watermark metrics show the consumer latency of Source.
It allows the user to know the health of the job, or it can be used to monitor and alarm.
Since each runner is likely already tracking a watermark, another option here is to just have the runner report it appropriately, rather than having the source report it using metrics. This also addresses the fact that even if the source has advanced to 8:00, the runner may still know about buffered elements at 7:00, and so not advance the watermark all the way to 8:00. Ben Chambers
1.Source watermark (`min` amongst all splits):
type = Gauge, namespace = io, name = source_watermark
2.Source watermark per split:
type = Gauge, namespace = io.splits, name = <split_id>.source_watermark