As the call stack shows, the mongodb connector is not compatible with the Spark 
SQL Data Source interface. The latest Data Source API is changed since 1.2, 
probably you need to confirm which spark version the MongoDB Connector build 
against.

By the way, a well format call stack will be more helpful for people reading.

From: taoewang [mailto:taoew...@sequoiadb.com]
Sent: Tuesday, March 3, 2015 7:39 PM
To: user@spark.apache.org
Subject: java.lang.IncompatibleClassChangeError when using PrunedFilteredScan



Hi,



I’m trying to build the stratio spark-mongodb connector and got error 
"java.lang.IncompatibleClassChangeError: class 
com.stratio.deep.mongodb.MongodbRelation has interface 
org.apache.spark.sql.sources.PrunedFilteredScan as super class” when trying to 
create a table using the driver:



scala> import org.apache.spark.sql.SQLContext

val sqlContext = new SQLContext(sc)import org.apache.spark.sql.SQLContext



import org.apache.spark.sql.SQLContext



scala> val sqlContext = new SQLContext(sc)

sqlContext: org.apache.spark.sql.SQLContext = 
org.apache.spark.sql.SQLContext@37050c15<mailto:org.apache.spark.sql.SQLContext@37050c15>



scala> import com.stratio.deep.mongodb

import com.stratio.deep.mongodb

import com.stratio.deep.mongodb



scala> sqlContext.sql("CREATE TEMPORARY TABLE students_table USING 
com.stratio.deep.mongodb OPTIONS (host 'host:port', database 'highschool', 
collection 'students')")

sqlContext.sql("CREATE TEMPORARY TABLE students_table USING com.stratio.d

eep.mongodb OPTIONS (host 'host:port', database 'highschool', collection 'studen

ts')")

java.lang.IncompatibleClassChangeError: class 
com.stratio.deep.mongodb.MongodbRelation has interface 
org.apache.spark.sql.sources.PrunedFilteredScan as super class

at java.lang.ClassLoader.defineClass1(Native Method)

at java.lang.ClassLoader.defineClass(ClassLoader.java:800)

at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)

at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)

at java.net.URLClassLoader.access$100(URLClassLoader.java:71)

at java.net.URLClassLoader$1.run(URLClassLoader.java:361)

at java.net.URLClassLoader$1.run(URLClassLoader.java:355)

at java.security.AccessController.doPrivileged(Native Method)

at java.net.URLClassLoader.findClass(URLClassLoader.java:354)

at java.lang.ClassLoader.loadClass(ClassLoader.java:425)

at java.lang.ClassLoader.loadClass(ClassLoader.java:358)

at java.lang.Class.getDeclaredConstructors0(Native Method)

at java.lang.Class.privateGetDeclaredConstructors(Class.java:2585)

at java.lang.Class.getConstructor0(Class.java:2885)

at java.lang.Class.newInstance(Class.java:350)

at org.apache.spark.sql.sources.ResolvedDataSource$.apply(ddl.scala:288)

at org.apache.spark.sql.sources.CreateTempTableUsing.run(ddl.scala:376)

at 
org.apache.spark.sql.execution.ExecutedCommand.sideEffectResult$lzycompute(commands.scala:55)

at 
org.apache.spark.sql.execution.ExecutedCommand.sideEffectResult(commands.scala:55)



The code failed at line 288 in ddl.scala:

  def apply(

      sqlContext: SQLContext,

      userSpecifiedSchema: Option[StructType],

      provider: String,

      options: Map[String, String]): ResolvedDataSource = {

    val clazz: Class[_] = lookupDataSource(provider)

    val relation = userSpecifiedSchema match {

      case Some(schema: StructType) => clazz.newInstance() match {

        case dataSource: SchemaRelationProvider =>

          dataSource.createRelation(sqlContext, new 
CaseInsensitiveMap(options), schema)

        case dataSource: org.apache.spark.sql.sources.RelationProvider =>

          sys.error(s"${clazz.getCanonicalName} does not allow user-specified 
schemas.")

      }



      case None => clazz.newInstance() match {  <——— failed here

        case dataSource: RelationProvider =>

          dataSource.createRelation(sqlContext, new CaseInsensitiveMap(options))

        case dataSource: org.apache.spark.sql.sources.SchemaRelationProvider =>

          sys.error(s"A schema needs to be specified when using 
${clazz.getCanonicalName}.")

      }

    }

    new ResolvedDataSource(clazz, relation)

  }



The “clazz” here is com.stratio.deep.mongodb.DefaultSource, which extends 
RelationProvider:

class DefaultSource extends RelationProvider {



  override def createRelation(

    sqlContext: SQLContext,

    parameters: Map[String, String]): BaseRelation = {



    /** We will assume hosts are provided like 'host:port,host2:port2,...'*/

    val host = parameters

      .getOrElse(Host, notFound[String](Host))

      .split(",").toList



    val database = parameters.getOrElse(Database, notFound(Database))



    val collection = parameters.getOrElse(Collection, notFound(Collection))



    val samplingRatio = parameters

      .get(SamplingRatio)

      .map(_.toDouble).getOrElse(DefaultSamplingRatio)



    MongodbRelation(

      MongodbConfigBuilder()

        .set(Host,host)

        .set(Database,database)

        .set(Collection,collection)

        .set(SamplingRatio,samplingRatio).build())(sqlContext)



  }



}



In createRelation function it returns MongodbRelation, which is extended from 
PrunedFilteredScan

case class MongodbRelation(

  config: DeepConfig,

  schemaProvided: Option[StructType] = None)(

  @transient val sqlContext: SQLContext) extends PrunedFilteredScan {



Since both TableScan and PrunedFilteredScan are based on BaseRelation, I’m not 
sure why clazz.newInstance() call failed by 
java.lang.IncompatibleClassChangeError.

Is there any special way to deal with if I need to use PrunedFilteredScan?



I’m using scala 2.10 and JDK 1.7



Thanks

TW

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