Hi lenduha, > When set the time characteristics to ProcessingTime via setStreamTimeCharacteristic(...) call, I cannot see watermarks in the Flink UI.
The watermark would be swallowed in the case. > can I use Event Time Timers even if I set the time characteristics to ProcessingTime (via ctx.timerService().registerEventTimeTimer(...))? I'm afraid not. The event time Timers could not work after setting ProcessingTime by setStreamTimeCharacteristic, because the watermark should be swallowed in the case, so the event time timers would not be triggered. > when I set the time characteristics to Event Time can I use both processing time timers & event time timers without any problem? Event time timers could work, of course. Besides, explicitly using processing-time windows and timers works in event-time mode. Please note that In Flink1.12, the default stream time characteristic has been changed to EventTime [1]. [1] https://ci.apache.org/projects/flink/flink-docs-release-1.13/release-notes/flink-1.12/#flip-134-batch-execution-for-the-datastream-api Best regards, JING ZHANG Deniz Koçak <lend...@gmail.com> 于2021年6月28日周一 下午2:43写道: > Hi, > > In environment configuration when set the time characteristics to > ProcessingTime via setStreamTimeCharacteristic(...) call, I cannot see > watermarks in the Flink UI. I think this is expected, because > watermarks disabled in the source (using Kafka as source)? > > Another point here is, can I use Event Time Timers even if I set the > time characteristics to ProcessingTime (via > ctx.timerService().registerEventTimeTimer(...))? As far as I > understood from the documentation, Event Time Timers needs watermarks > which sets the operator time, so I wonder if I can use event time > timers in case of ProcessingTime selected in the environment? Also > when I set the time characteristics to Event Time can I use both > processing time timers & event time timers without any problem? > > Thanks, >