[FLINK-6808] Stream join fails when checkpointing is enabled

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 1.3.0
• Fix Version/s: 1.3.1
• Component/s: API / DataStream
• Labels: flink-rel-1.3.1-blockers
• Assignee: Tzu-Li (Gordon) Tai
• Reporter: Francisco Rosa
• Created: 02/Jun/17 02:32
• Updated: 07/Jun/17 17:27
• Resolved: 07/Jun/17 17:27

Description

The combination of joining streams and checkpointing fails in 1.3.0. It used to work with the previous 1.2 version. Code example for failure:

Example

    public static void main(String[] args) throws Exception {

        final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        // enable checkpoints
        env.enableCheckpointing(5000);

        // create two streams
        DataStreamSource<Long> one = env.generateSequence(0, 5000);
        DataStreamSource<Long> two = env.generateSequence(2000, 15000);

        // process both, provide a delay to make sure checkpoint will happen
        DataStream<String> oneProcessed = one.
                map(oneValue -> {
                    Thread.sleep(1000);
                    return "val-" + oneValue;
                });
        DataStream<String> twoProcessed = two.
                map(oneValue -> {
                    Thread.sleep(1000);
                    return "val-" + oneValue;
                });

        // join the two streams, join on string match
        DataStream<String> joinedStreams = oneProcessed.
                join(twoProcessed).
                where(String::toString).
                equalTo(String::toString).
                window(TumblingProcessingTimeWindows.of(Time.seconds(5))).
                apply(new JoinFunction<String, String, String>() {
                    @Override
                    public String join(String oneValue, String twoValue) {
                        // nothing really relevant, just concatenate string
                        return oneValue + "+" + twoValue;
                    }
                });

        // output results
        joinedStreams.print();

        env.execute("Issue with stream join and checkpoints");
    }

Stack trace:

java.lang.Exception: Could not perform checkpoint 1 for operator TriggerWindow(TumblingProcessingTimeWindows(5000), ListStateDescriptor{serializer=org.apache.flink.api.common.typeutils.base.ListSerializer@3769cce0}, ProcessingTimeTrigger(), WindowedStream.apply(CoGroupedStreams.java:300)) -> Sink: Unnamed (1/1).
	at org.apache.flink.streaming.runtime.tasks.StreamTask.triggerCheckpointOnBarrier(StreamTask.java:550)
	at org.apache.flink.streaming.runtime.io.BarrierBuffer.notifyCheckpoint(BarrierBuffer.java:378)
	at org.apache.flink.streaming.runtime.io.BarrierBuffer.processBarrier(BarrierBuffer.java:281)
	at org.apache.flink.streaming.runtime.io.BarrierBuffer.getNextNonBlocked(BarrierBuffer.java:183)
	at org.apache.flink.streaming.runtime.io.StreamInputProcessor.processInput(StreamInputProcessor.java:213)
	at org.apache.flink.streaming.runtime.tasks.OneInputStreamTask.run(OneInputStreamTask.java:69)
	at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:262)
	at org.apache.flink.runtime.taskmanager.Task.run(Task.java:702)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.Exception: Could not complete snapshot 1 for operator TriggerWindow(TumblingProcessingTimeWindows(5000), ListStateDescriptor{serializer=org.apache.flink.api.common.typeutils.base.ListSerializer@3769cce0}, ProcessingTimeTrigger(), WindowedStream.apply(CoGroupedStreams.java:300)) -> Sink: Unnamed (1/1).
	at org.apache.flink.streaming.api.operators.AbstractStreamOperator.snapshotState(AbstractStreamOperator.java:406)
	at org.apache.flink.streaming.runtime.tasks.StreamTask$CheckpointingOperation.checkpointStreamOperator(StreamTask.java:1157)
	at org.apache.flink.streaming.runtime.tasks.StreamTask$CheckpointingOperation.executeCheckpointing(StreamTask.java:1089)
	at org.apache.flink.streaming.runtime.tasks.StreamTask.checkpointState(StreamTask.java:653)
	at org.apache.flink.streaming.runtime.tasks.StreamTask.performCheckpoint(StreamTask.java:589)
	at org.apache.flink.streaming.runtime.tasks.StreamTask.triggerCheckpointOnBarrier(StreamTask.java:542)
	... 8 more
Caused by: java.lang.UnsupportedOperationException: This serializer is not registered for managed state.
	at org.apache.flink.streaming.api.datastream.CoGroupedStreams$UnionSerializer.snapshotConfiguration(CoGroupedStreams.java:555)
	at org.apache.flink.api.common.typeutils.CompositeTypeSerializerConfigSnapshot.<init>(CompositeTypeSerializerConfigSnapshot.java:53)
	at org.apache.flink.api.common.typeutils.base.CollectionSerializerConfigSnapshot.<init>(CollectionSerializerConfigSnapshot.java:39)
	at org.apache.flink.runtime.state.ArrayListSerializer.snapshotConfiguration(ArrayListSerializer.java:149)
	at org.apache.flink.runtime.state.RegisteredKeyedBackendStateMetaInfo.snapshot(RegisteredKeyedBackendStateMetaInfo.java:71)
	at org.apache.flink.runtime.state.heap.HeapKeyedStateBackend.snapshot(HeapKeyedStateBackend.java:267)
	at org.apache.flink.streaming.api.operators.AbstractStreamOperator.snapshotState(AbstractStreamOperator.java:396)
	... 13 more

Issue Links

• links to: GitHub Pull Request #4052