zhengcanbin created FLINK-9460:
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             Summary: Redundant output in table & upsert semantics
                 Key: FLINK-9460
                 URL: https://issues.apache.org/jira/browse/FLINK-9460
             Project: Flink
          Issue Type: Bug
          Components: Table API & SQL
    Affects Versions: 1.5.0
            Reporter: zhengcanbin
             Fix For: 1.6.0
         Attachments: image-2018-05-29-11-39-45-698.png, 
image-2018-05-29-11-51-20-671.png

The output seems incorrect in my table & upsert example, here's the code:
{code:java}
object VerifyUpsert {

  def main(args: Array[String]): Unit = {
    val env = StreamExecutionEnvironment.createLocalEnvironment()
    val tEnv = TableEnvironment.getTableEnvironment(env)
    env.setParallelism(1)

    val input = env.socketTextStream("localhost", 9099).map { x =>
      val tokens = x.split(",")
      DemoSource(tokens(0), tokens(1), tokens(2))
    }

    tEnv.registerDataStream("demoSource", input, 'record_time, 'user_id, 
'page_id)

    val fieldNames = Array("record_time", "pv", "uv")
    val fieldTypes = Array(Types.STRING, Types.LONG, 
Types.LONG).asInstanceOf[Array[TypeInformation[_]]]
    tEnv.registerTableSink("demoSink", fieldNames, fieldTypes, 
MyPrintSink(fieldNames, fieldTypes))

    tEnv.sqlUpdate(
      """
        |INSERT INTO demoSink
        |SELECT
        |  SUBSTRING(record_time, 1, 16) as record_time,
        |  count(user_id) as pv,
        |  count(DISTINCT user_id) as uv
        |FROM demoSource
        |GROUP BY SUBSTRING(record_time, 1, 16)
      """.stripMargin)

    env.execute()
  }

  case class DemoSource(record_time: String, user_id: String, page_id: String)

}

case class MyPrintSink(var fNames: Array[String], var fTypes: 
Array[TypeInformation[_]]) extends UpsertStreamTableSink[Row] {

  override def setKeyFields(keys: Array[String]): Unit = Seq.empty

  override def setIsAppendOnly(isAppendOnly: lang.Boolean): Unit = {}

  override def getRecordType: TypeInformation[Row] = new RowTypeInfo(fTypes, 
fNames)

  override def emitDataStream(dataStream: DataStream[tuple.Tuple2[lang.Boolean, 
Row]]): Unit = dataStream.addSink(new PrintSinkFunction())

  override def getFieldNames: Array[String] = fNames

  override def getFieldTypes: Array[TypeInformation[_]] = fTypes

  override def configure(fieldNames: Array[String], fieldTypes: 
Array[TypeInformation[_]]): TableSink[tuple.Tuple2[lang.Boolean, Row]] = {
    val copy = MyPrintSink(fNames, fTypes)
    copy.fNames = fieldNames
    copy.fTypes = fieldTypes
    copy
  }
}{code}
when application starts, I type in netcat client one record a time,  below 
table shows outputs for every input record:

 
||input||output||
|2018-05-24 21:34:02,8,9|(true,2018-05-24 21:34,1,1)|
|2018-05-24 21:34:12,6,6|(true,2018-05-24 21:34,2,2)|
|2018-05-24 21:34:12,0,9|(true,2018-05-24 21:34,3,3)|
|2018-05-24 21:34:12,0,4|{color:#FF0000}(true,2018-05-24 21:34,2,2){color}
(true,2018-05-24 21:34,4,3)|

 

when the forth record is consumed, two output records would be printed in sink, 
obviously the first one record with red color is redundant. I followed the 
source code and found something wrong with 

 
{code:java}
org.apache.flink.table.runtime.aggregate.GroupAggProcessFunction#processElement
{code}
!image-2018-05-29-11-51-20-671.png!

I think when (!generateRetraction) && !inputC.change is true, we should not 
invoke out.collect here.

 

[~astephan] please look over this



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