[ https://issues.apache.org/jira/browse/FLINK-3435?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15150676#comment-15150676 ]
Stephan Ewen commented on FLINK-3435: ------------------------------------- Given that this is quite fundamental, I think it becomes an issue to be resolved before the next release candidate. > Change interplay of Ingestion Time and Event Time > ------------------------------------------------- > > Key: FLINK-3435 > URL: https://issues.apache.org/jira/browse/FLINK-3435 > Project: Flink > Issue Type: Improvement > Components: Streaming > Affects Versions: 0.10.2 > Reporter: Stephan Ewen > Fix For: 1.0.0 > > > Currently, "EventTime" and "IngestionTime" are completely the same. > For both happens the following: > - Sources generate ingestion time timestamps and watermarks > - If a user adds a manual timestamp extractor / watermark generator, then > those override the ingestion time timestamps and watermarks > - That implies that event time on a certain input falls back to ingestion > time, if one forgets (or incorrectly uses) the timestamp extractors > - Also, Ingestion Time and Event Time simply mix if some inputs have > timestamp assigners, and others have not. > This behavior is quite tricky to understand. After some discussions with > [~aljoscha] and [~rmetzger], we suggest to change it the following way. > 1. On Ingestion Time, the timestamps and watermarks are generated as they > are now. > 2. On event time, no default timestamps and watermarks are generated. If a > user does not implement a timestamp extractor / watermark generator, then the > event time operations will fail fast. > 3. If one wants to use ingestion time on event time settings (mix), one can > use an explicit "WallClockTimetampsAndWatermark" generator. > 4. Later, the "Ingestion Time" settings should automatically disable and > user-defined timestamp extractors / assigners. -- This message was sent by Atlassian JIRA (v6.3.4#6332)