[FLINK-10116] createComparator fails on case class with Unit type fields prior to the join-key

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.3.3, 1.6.0
• Fix Version/s: 1.4.3, 1.5.4, 1.6.1, 1.7.0
• Component/s: API / DataSet
• Labels: pull-request-available
• Assignee: Fabian Hueske
• Reporter: Will
• Created: 09/Aug/18 17:48
• Updated: 16/Aug/18 20:58
• Resolved: 16/Aug/18 20:58

Description

Overview

When joining between case classes, if the attribute representing the join-key comes after Unit definition of fields (that are not being used) the join will fail with the error

Exception in thread "main" java.lang.IllegalArgumentException: Could not add a comparator for the logicalkey field index 0.
{{ at org.apache.flink.api.common.typeutils.CompositeType.createComparator(CompositeType.java:162)}}
{{ at org.apache.flink.optimizer.postpass.JavaApiPostPass.createComparator(JavaApiPostPass.java:293)}}
{{ at org.apache.flink.optimizer.postpass.JavaApiPostPass.traverse(JavaApiPostPass.java:193)}}

Using TypeInformation keys does not exhibit the same issue. Initial debugging suggests that when calculating the index of the key for strings, Flink doesn't count Unit elements, however they are included during iteration in CompositeType.createComparator which leads to the search failing on the key appearing to be a Unit type.

Code Examples to Reproduce

JobFail.scala

JobPass.scala

 

^{Inline Code}

^Fail

package org.demo

/**
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

import org.apache.flink.api.common.functions.RichJoinFunction
import org.apache.flink.api.java.DataSet
import org.apache.flink.api.scala._


object JobFail {

  case class LeftJoin (
                        FieldA: String = "",
                        FieldB: String = "",
                        FieldC: String = "",
                        JoinIndex: String = ""
                      )

  case class RightJoin (
                         FieldD: Unit = Unit,
                         FieldE: Unit = Unit,
                         FieldF: Unit = Unit,
                         JoinIndex: String = ""
                       )

  case class Merged (
                      var FieldA: String = "",
                      var FieldB: String = "",
                      var FieldC: String = "",
                      var FieldD: String = "",
                      var FieldE: String = "",
                      var FieldF: String = "",
                      var JoinIndex: String = ""
                    )

  class JoinHelper() extends RichJoinFunction[LeftJoin, RightJoin, Merged]{
    override def join(first: LeftJoin, second: RightJoin): Merged = {
      val out = new Merged()
      out.FieldA = first.FieldA
      out.FieldB = first.FieldB
      out.FieldC = first.FieldC
      if (second != null){
        /*out.FieldD = second.FieldD
        out.FieldE = second.FieldE
        out.FieldF = second.FieldF*/
      }

      out
    }
  }

  def main(args: Array[String]) {
    // set up the execution environment
    val env = ExecutionEnvironment.getExecutionEnvironment
    val leftOne = new LeftJoin("FieldA1", "FieldB1", "FieldC1", "index")
    val rightOne = new RightJoin("FieldD1", "FieldE1", "FieldF1", "index")

    val left = env.fromElements(leftOne)
    val right = env.fromElements(rightOne)

    // TODO: String key fails
    val joined = left.leftOuterJoin(right).where("JoinIndex").equalTo("JoinIndex").apply(new JoinHelper())
    joined.print()


  }
}

^Pass

package org.demo

/**
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

import org.apache.flink.api.common.functions.RichJoinFunction
import org.apache.flink.api.java.DataSet
import org.apache.flink.api.scala._

object JobPass {

  case class LeftJoin (
                        FieldA: String = "",
                        FieldB: String = "",
                        FieldC: String = "",
                        JoinIndex: String = ""
                      )

  case class RightJoin (
                         FieldD: Unit = Unit,
                         FieldE: Unit = Unit,
                         FieldF: Unit = Unit,
                         JoinIndex: String = ""
                       )

  case class Merged (
                      var FieldA: String = "",
                      var FieldB: String = "",
                      var FieldC: String = "",
                      var FieldD: String = "",
                      var FieldE: String = "",
                      var FieldF: String = "",
                      var JoinIndex: String = ""
                    )

  class JoinHelper() extends RichJoinFunction[LeftJoin, RightJoin, Merged]{
    override def join(first: LeftJoin, second: RightJoin): Merged = {
      val out = new Merged()
      out.FieldA = first.FieldA
      out.FieldB = first.FieldB
      out.FieldC = first.FieldC
      if (second != null){
        /*out.FieldD = second.FieldD
        out.FieldE = second.FieldE
        out.FieldF = second.FieldF*/
      }

      out
    }
  }

  def main(args: Array[String]) {
    // set up the execution environment
    val env = ExecutionEnvironment.getExecutionEnvironment
    val leftOne = new LeftJoin("FieldA1", "FieldB1", "FieldC1", "index")
    val rightOne = new RightJoin("FieldD1", "FieldE1", "FieldF1", "index")

    val left = env.fromElements(leftOne)
    val right = env.fromElements(rightOne)

    // TODO: TypeInformation key passes
    val joined = left.leftOuterJoin(right).where(_.JoinIndex).equalTo(_.JoinIndex).apply(new JoinHelper())
    joined.print()
  }
}

 

 

Issue Links

• links to: GitHub Pull Request #6569