[FLINK-6930] Selecting window start / end on row-based Tumble/Slide window causes NPE

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.3.0, 1.4.0
• Fix Version/s: 1.3.1, 1.4.0
• Component/s: Table SQL / API
• Assignee: Jark Wu
• Reporter: Fabian Hueske
• Created: 15/Jun/17 13:23
• Updated: 19/Jun/17 22:23
• Resolved: 19/Jun/17 22:23

Description

Selecting the start and end properties of a row-based window causes a NullPointerException.
The following program:

val windowedTable = table
      .window(Tumble over 2.rows on 'proctime as 'w)
      .groupBy('w, 'string)
      .select('string as 'n, 'int.count as 'cnt, 'w.start as 's, 'w.end as 'e)

causes

Caused by: java.lang.NullPointerException
	at org.apache.calcite.runtime.SqlFunctions.toLong(SqlFunctions.java:1556)
	at org.apache.calcite.runtime.SqlFunctions.toLong(SqlFunctions.java:1551)
	at DataStreamCalcRule$40.processElement(Unknown Source)
	at org.apache.flink.table.runtime.CRowProcessRunner.processElement(CRowProcessRunner.scala:67)
	at org.apache.flink.table.runtime.CRowProcessRunner.processElement(CRowProcessRunner.scala:35)
	at org.apache.flink.streaming.api.operators.ProcessOperator.processElement(ProcessOperator.java:66)
	at org.apache.flink.streaming.runtime.tasks.OperatorChain$CopyingChainingOutput.pushToOperator(OperatorChain.java:528)
	at org.apache.flink.streaming.runtime.tasks.OperatorChain$CopyingChainingOutput.collect(OperatorChain.java:503)
	at org.apache.flink.streaming.runtime.tasks.OperatorChain$CopyingChainingOutput.collect(OperatorChain.java:483)
	at org.apache.flink.streaming.api.operators.AbstractStreamOperator$CountingOutput.collect(AbstractStreamOperator.java:890)
	at org.apache.flink.streaming.api.operators.AbstractStreamOperator$CountingOutput.collect(AbstractStreamOperator.java:868)
	at org.apache.flink.streaming.api.operators.TimestampedCollector.collect(TimestampedCollector.java:51)
	at org.apache.flink.table.runtime.aggregate.IncrementalAggregateWindowFunction.apply(IncrementalAggregateWindowFunction.scala:75)
	at org.apache.flink.table.runtime.aggregate.IncrementalAggregateWindowFunction.apply(IncrementalAggregateWindowFunction.scala:37)
	at org.apache.flink.streaming.runtime.operators.windowing.functions.InternalSingleValueWindowFunction.process(InternalSingleValueWindowFunction.java:46)
	at org.apache.flink.streaming.runtime.operators.windowing.WindowOperator.emitWindowContents(WindowOperator.java:599)
	at org.apache.flink.streaming.runtime.operators.windowing.WindowOperator.processElement(WindowOperator.java:456)
	at org.apache.flink.streaming.runtime.io.StreamInputProcessor.processInput(StreamInputProcessor.java:207)
	at org.apache.flink.streaming.runtime.tasks.OneInputStreamTask.run(OneInputStreamTask.java:69)
	at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:265)
	at org.apache.flink.runtime.taskmanager.Task.run(Task.java:702)
	at java.lang.Thread.run(Thread.java:745)

We should validate that the start and end window properties are not accessed if the window is defined on row-counts.

Issue Links

• links to: GitHub Pull Request #4133