[FLINK-6001] NPE on TumblingEventTimeWindows with ContinuousEventTimeTrigger and allowedLateness

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 1.2.0
• Fix Version/s: 1.2.1, 1.3.0
• Component/s: API / DataStream
• Assignee: Aljoscha Krettek
• Reporter: Vladislav Pernin
• Created: 08/Mar/17 17:00
• Updated: 28/Feb/19 10:46
• Resolved: 15/Mar/17 13:48

Description

I try to isolate the problem in a small and simple reproducer by extracting the data from my real setup.

I fails with NPE at :

java.lang.NullPointerException: null
	at org.apache.flink.streaming.api.windowing.triggers.ContinuousEventTimeTrigger.onEventTime(ContinuousEventTimeTrigger.java:81) ~[flink-streaming-java_2.11-1.2.0.jar:1.2.0]
	at org.apache.flink.streaming.runtime.operators.windowing.WindowOperator$Context.onEventTime(WindowOperator.java:721) ~[flink-streaming-java_2.11-1.2.0.jar:1.2.0]
	at org.apache.flink.streaming.runtime.operators.windowing.WindowOperator.onEventTime(WindowOperator.java:425) ~[flink-streaming-java_2.11-1.2.0.jar:1.2.0]
	at org.apache.flink.streaming.api.operators.HeapInternalTimerService.advanceWatermark(HeapInternalTimerService.java:276) ~[flink-streaming-java_2.11-1.2.0.jar:1.2.0]
	at org.apache.flink.streaming.api.operators.AbstractStreamOperator.processWatermark(AbstractStreamOperator.java:858) ~[flink-streaming-java_2.11-1.2.0.jar:1.2.0]
	at org.apache.flink.streaming.runtime.io.StreamInputProcessor.processInput(StreamInputProcessor.java:168) ~[flink-streaming-java_2.11-1.2.0.jar:1.2.0]
	at org.apache.flink.streaming.runtime.tasks.OneInputStreamTask.run(OneInputStreamTask.java:63) ~[flink-streaming-java_2.11-1.2.0.jar:1.2.0]
	at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:272) ~[flink-streaming-java_2.11-1.2.0.jar:1.2.0]
	at org.apache.flink.runtime.taskmanager.Task.run(Task.java:655) ~[flink-runtime_2.11-1.2.0.jar:1.2.0]
	at java.lang.Thread.run(Thread.java:745) ~[na:1.8.0_121]

It fails only with the Thread.sleep. If you uncomment it, it won't fail.
So, you may have to increase the sleep time depending of your environment.
I know this is not a very rigourous test, but this is the only way I've found to reproduce it.

You can find the reproducer here :
https://github.com/vpernin/flink-window-npe

Issue Links

• links to: GitHub Pull Request #3544