Re: watermark VS window trigger

2018-07-31 Thread Fabian Hueske
Hi, Watermarks are not holding back records. Instead they define the event-time at an operator (as Vino said) and can trigger the processing of data if the logic of an operator is based on time. For example, a window operator can emit complete results for a window once the time passed the

Re: watermark VS window trigger

2018-07-30 Thread vino yang
Hi Soheil, I feel that some of your understanding is a bit problematic. *"After that according to the current watermark, data with the timestamp between the last watermark and current watermark will be released and go to the next steps"* The main role of Watermark here is to define the progress

watermark VS window trigger

2018-07-30 Thread Soheil Pourbafrani
Suppose we have a time window of 10 milliseconds and we use EventTime. First, we determine how Flink can get time and watermark from incoming messages, after that, we set a key for the stream and set a time window. aggregatedTuple .assignTimestampsAndWatermarks(new