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ASF GitHub Bot commented on FLINK-3435: --------------------------------------- Github user aljoscha commented on a diff in the pull request: https://github.com/apache/flink/pull/1699#discussion_r53984915 --- Diff: flink-streaming-java/src/main/java/org/apache/flink/streaming/api/functions/IngestionTimeExtractor.java --- @@ -0,0 +1,40 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.flink.streaming.api.functions; + +import org.apache.flink.streaming.api.watermark.Watermark; + +/** + * A timestamp assigner that assigns ingestion time timestamps. + * + * @param <T> The elements that get timestamps assigned. + */ +public class IngestionTimeExtractor<T> implements AssignerWithPeriodicWatermarks<T> { --- End diff -- Should it maybe be call "WallClockTimeExtractor" or something similar? Since it's not really the ingestion time if timestamp assignment does not happen in the sources. > 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 > Assignee: Stephan Ewen > Priority: Blocker > 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)