The BoundedOutOfOrdernessTimestampExtractor  is assigned to datastream after 
kafka consumer. The graph is like:

KafkaSource-> map2Pojo -> BoundedOutOfOrdernessTimestampExtractor -> Table -> 
......



________________________________
From: Yan Zhou [FDS Science] <[email protected]>
Sent: Wednesday, May 23, 2018 3:21:24 PM
To: [email protected]
Subject: increasing parallelism increases the end2end latency in flink sql


Hi,


My application assigned timestamp to kafka event with 
BoundedOutOfOrdernessTimestampExtractor then converted them to a table. Finally 
flink SQL over-window aggregation is run against the table.


When I double the parallelism of my flink application, the end2end latency is 
doubled.  What could be the cause? It seems to me that it's because of slower 
advance of watermark in operator of operators generated by sql.


In this email thread [1], it's said that flink sql remove the internal 
DataStream timestamp and move it into the record. Does the query ignore the 
internal DataStream watermarks and re-generate them from the record? Let say 
there are two operator instances for one task, do they have same watermark?


There is a similar issue that i can find in the email thread [2] .


Best

Yan


[1]: 
https://lists.apache.org/thread.html/c5182628272f018037ce832290f9b19976fe5c268aa72760635cf3cc@%3Cuser.flink.apache.org%3E

[2]: 
https://lists.apache.org/thread.html/bf789df06e979f80caf23f6b2c8676aaf07b007ae0d450ae887b6a82@%3Cuser.flink.apache.org%3E

Reply via email to