Re: why operator not chained?

Posted by Guowei Ma on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/why-operator-not-chained-tp31168p31175.html

Hi, Steven

1. The `icebergsink-writer` operator does not chain with the first operator is because the "icebergsink-writer" operator 's ChainingStrategy is NULL or HEAD. You could verify it by printing writer.getChainingStrategy.

2. The two operators use the FORWARD partition if the parallelism of two operators is the same and the partitioner is not specified by the user.

Steven Wu <[hidden email]> 于2019年11月23日周六 上午5:17写道：

I have this DAG screenshot from Flink UI.

I am wondering why is the middle "icebergsink-writer" operator not chained with the first operator chain? 

Or an equivalent question is why is forward partitioner used here?

The first operator chain are all map functions after source. The last two operators are added like this.

--------------------------

dataStream
    .transform("icebergsink-writer", TypeInformation.of(SomeClass.class), writer)
    .addSink(committer)
    .name("icebergsink-committer")
    .uid("icebergsink-committer")
    .setParallelism(1);

Thanks,

Steven