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From Chesnay Schepler <ches...@apache.org>
Subject Re: SideOutput Issue
Date Thu, 05 Apr 2018 08:25:45 GMT
We were able to reproduce the issue.
It was caused by calling getSideOutput() and split() on a single 
DataStream, which isn't properly handled by Flink.
As a work-around one can add a no-op map function before the split() call.

I've filed FLINK-9141 <https://issues.apache.org/jira/browse/FLINK-9141>.

On 04.04.2018 12:21, Chesnay Schepler wrote:
> Hi,
>
> which version of Flink are you using?
>
> Could you provide us with a reproducing example? I tried reproducing 
> it based on the information you provided in the following code, but it 
> runs fine for me:
>
>     private static final OutputTag<String> tag = new 
> OutputTag<String>("test"){};
>
>     public static void main(String[] args) throws Exception {
>         final StreamExecutionEnvironment env = 
> StreamExecutionEnvironment.getExecutionEnvironment();
>
>         DataStream<String> text1 = env.fromElements("foo");
>         DataStream<String> text2 = env.fromElements("bar");
>
>         SingleOutputStreamOperator<String> process = text1.connect(text2)
> .process(new CoProcessFunction<String, String, String>() {
> @Override
> public void processElement1(String value, Context ctx, 
> Collector<String> out) throws Exception {
> }
>
> @Override
> public void processElement2(String value, Context ctx, 
> Collector<String> out) throws Exception {
> }
>         });
>
>         process.getSideOutput(tag).print();
>
>         // execute program
>         env.execute("Streaming WordCount");
>     }
> On 03.04.2018 19:55, Navneeth Krishnan wrote:
>> Hi All,
>>
>> I'm having issues with creating side outputs. There are two input 
>> sources (both from kafka) and they are connected and fed into a 
>> co-process function. Inside the co-process, the regular data stream 
>> outputs a POJO and in processElement2 there is a periodic timer which 
>> creates the side output. When I start the job I get the below 
>> exception. Is there something that I'm doing wrong?
>>
>> I used the below example to implement the side output.
>> https://github.com/apache/flink/blob/master/flink-examples/flink-examples-streaming/src/main/java/org/apache/flink/streaming/examples/sideoutput/SideOutputExample.java
>>
>> processElement2
>> ctx.output("side-output", POJO);
>>
>> Job
>> dataStream.getSideOutput("side-output").print();
>>
>>
>> 2018-04-03 10:18:38.821 [Co-Flat Map (4/8)] INFO 
>> org.apache.flink.runtime.taskmanager.Task  - Co-Flat Map (4/8) 
>> (20b92b7a8cdd1e63963886de0895882c) switched from CREATED to DEPLOYING.
>> 2018-04-03 10:18:38.821 [Co-Process (1/8)] INFO 
>> org.apache.flink.runtime.taskmanager.Task  - Co-Process (1/8) 
>> (fd8f971eea2e103e340d2955b384eaa3) switched from RUNNING to FAILED.
>> java.lang.NullPointerException: null
>> at 
>> org.apache.flink.streaming.api.collector.selector.DirectedOutput.<init>(DirectedOutput.java:74)
>> at 
>> org.apache.flink.streaming.api.collector.selector.CopyingDirectedOutput.<init>(CopyingDirectedOutput.java:40)
>> at 
>> org.apache.flink.streaming.runtime.tasks.OperatorChain.createOutputCollector(OperatorChain.java:329)
>> at 
>> org.apache.flink.streaming.runtime.tasks.OperatorChain.<init>(OperatorChain.java:126)
>> at 
>> org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:231)
>> at org.apache.flink.runtime.taskmanager.Task.run(Task.java:718)
>> at java.lang.Thread.run(Thread.java:745)
>>
>> 2018-04-03 10:18:38.880 [Co-Process (7/8)] INFO 
>> org.apache.flink.runtime.taskmanager.Task  - Co-Process (7/8) 
>> (a86274f9ac49b71f00d218a1533cbd51) switched from RUNNING to FAILED.
>> java.lang.NullPointerException: null
>> at 
>> org.apache.flink.streaming.api.collector.selector.DirectedOutput.<init>(DirectedOutput.java:74)
>> at 
>> org.apache.flink.streaming.api.collector.selector.CopyingDirectedOutput.<init>(CopyingDirectedOutput.java:40)
>> at 
>> org.apache.flink.streaming.runtime.tasks.OperatorChain.createOutputCollector(OperatorChain.java:329)
>> at 
>> org.apache.flink.streaming.runtime.tasks.OperatorChain.<init>(OperatorChain.java:126)
>> at 
>> org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:231)
>> at org.apache.flink.runtime.taskmanager.Task.run(Task.java:718)
>> at java.lang.Thread.run(Thread.java:745)
>>
>> Thanks
>
>


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