[
https://issues.apache.org/jira/browse/FLINK-6116?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16006684#comment-16006684
]
Aljoscha Krettek commented on FLINK-6116:
-----------------------------------------
Got it! The problem is here
https://github.com/apache/flink/blob/6181302f1ab741b86af357e4513f5952a5fc1531/flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/tasks/OperatorChain.java#L264-L264
and here
https://github.com/apache/flink/blob/6181302f1ab741b86af357e4513f5952a5fc1531/flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/tasks/OperatorChain.java#L118-L118.
We properly create a {{RecordWriterOutput}} for each outgoing edge in the first
snipped but the two {{StreamEdges}} that we have are the same (regarding equals
and hashCode) and so we only have one entry in the {{streamOutputMap}} and
forget about the other {{RecordWriterOutput}}. In the second snipped, where we
wire up the outputs we wire the same output twice, because the lookup for the
two edges is the same again.
> Watermarks don't work when unioning with same DataStream
> --------------------------------------------------------
>
> Key: FLINK-6116
> URL: https://issues.apache.org/jira/browse/FLINK-6116
> Project: Flink
> Issue Type: Bug
> Components: DataStream API
> Affects Versions: 1.2.0, 1.3.0
> Reporter: Aljoscha Krettek
> Priority: Blocker
> Fix For: 1.3.0
>
>
> In this example job we don't get any watermarks in the {{WatermarkObserver}}:
> {code}
> public class WatermarkTest {
> public static void main(String[] args) throws Exception {
> final StreamExecutionEnvironment env =
> StreamExecutionEnvironment.getExecutionEnvironment();
>
> env.setStreamTimeCharacteristic(TimeCharacteristic.IngestionTime);
> env.getConfig().setAutoWatermarkInterval(1000);
> env.setParallelism(1);
> DataStreamSource<String> input = env.addSource(new
> SourceFunction<String>() {
> @Override
> public void run(SourceContext<String> ctx) throws
> Exception {
> while (true) {
> ctx.collect("hello!");
> Thread.sleep(800);
> }
> }
> @Override
> public void cancel() {
> }
> });
> input.union(input)
> .flatMap(new IdentityFlatMap())
> .transform("WatermarkOp",
> BasicTypeInfo.STRING_TYPE_INFO, new WatermarkObserver());
> env.execute();
> }
> public static class WatermarkObserver
> extends AbstractStreamOperator<String>
> implements OneInputStreamOperator<String, String> {
> @Override
> public void processElement(StreamRecord<String> element) throws
> Exception {
> System.out.println("GOT ELEMENT: " + element);
> }
> @Override
> public void processWatermark(Watermark mark) throws Exception {
> super.processWatermark(mark);
> System.out.println("GOT WATERMARK: " + mark);
> }
> }
> private static class IdentityFlatMap
> extends RichFlatMapFunction<String, String> {
> @Override
> public void flatMap(String value, Collector<String> out) throws
> Exception {
> out.collect(value);
> }
> }
> }
> {code}
> When commenting out the `union` it works.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
