Estoy usando un tutorial aquí en este Github para ejecutar chispa en cassandra usando un proyecto java maven:https://github.com/datastax/spark-cassandra-connector.

He descubierto cómo usar las declaraciones directas de CQL, ya que anteriormente hice una pregunta sobre eso aquí:Consulta de datos en Cassandra a través de Spark en un proyecto Java Maven

Sin embargo, ahora estoy tratando de utilizar la API Java DataStax por temor a que mi código original en mi pregunta original no funcione para la versión Datastax de Spark y Cassandra. Por alguna extraña razón, no me deja usar.where a pesar de que se describe en la documentación que puedo usar esa declaración exacta. Aquí está mi código:

import org.apache.commons.lang3.StringUtils;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.function.Function;

import java.io.Serializable;

import static com.datastax.spark.connector.CassandraJavaUtil.*;


public class App implements Serializable
{

    // firstly, we define a bean class
    public static class Person implements Serializable {
        private Integer id;
        private String fname;
        private String lname;
        private String role;

        // Remember to declare no-args constructor
        public Person() { }

        public Integer getId() { return id; }
        public void setId(Integer id) { this.id = id; }

        public String getfname() { return fname; }
        public void setfname(String fname) { this.fname = fname; }

        public String getlname() { return lname; }
        public void setlname(String lname) { this.lname = lname; }

        public String getrole() { return role; }
        public void setrole(String role) { this.role = role; }

        // other methods, constructors, etc.
    }

    private transient SparkConf conf;
    private App(SparkConf conf) {
        this.conf = conf;
    }


    private void run() {
        JavaSparkContext sc = new JavaSparkContext(conf);
        createSchema(sc);


        sc.stop();
    }

    private void createSchema(JavaSparkContext sc) {

        JavaRDD<String> rdd = javaFunctions(sc).cassandraTable("tester", "empbyrole", Person.class)
                .where("role=?", "IT Engineer").map(new Function<Person, String>() {
                    @Override
                    public String call(Person person) throws Exception {
                        return person.toString();
                    }
                });
        System.out.println("Data as Person beans: \n" + StringUtils.join("\n", rdd.toArray()));
       }



    public static void main( String[] args )
    {
        if (args.length != 2) {
            System.err.println("Syntax: com.datastax.spark.demo.JavaDemo <Spark Master URL> <Cassandra contact point>");
            System.exit(1);
        }

        SparkConf conf = new SparkConf();
        conf.setAppName("Java API demo");
        conf.setMaster(args[0]);
        conf.set("spark.cassandra.connection.host", args[1]);

        App app = new App(conf);
        app.run();
    }
}

Aquí está el error:

14/09/23 13:46:53 ERROR executor.Executor: Exception in task ID 0
java.io.IOException: Exception during preparation of SELECT "role", "id", "fname", "lname" FROM "tester"."empbyrole" WHERE token("role") > -5709068081826432029 AND token("role") <= -5491279024053142424 AND role=? ALLOW FILTERING: role cannot be restricted by more than one relation if it includes an Equal
    at com.datastax.spark.connector.rdd.CassandraRDD.createStatement(CassandraRDD.scala:310)
    at com.datastax.spark.connector.rdd.CassandraRDD.com$datastax$spark$connector$rdd$CassandraRDD$fetchTokenRange(CassandraRDD.scala:317)
    at com.datastax.spark.connector.rdd.CassandraRDD$anonfun$13.apply(CassandraRDD.scala:338)
    at com.datastax.spark.connector.rdd.CassandraRDD$anonfun$13.apply(CassandraRDD.scala:338)
    at scala.collection.Iterator$anon$13.hasNext(Iterator.scala:371)
    at com.datastax.spark.connector.util.CountingIterator.hasNext(CountingIterator.scala:10)
    at scala.collection.Iterator$anon$11.hasNext(Iterator.scala:327)
    at scala.collection.Iterator$class.foreach(Iterator.scala:727)
    at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
    at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:48)
    at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:103)
    at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:47)
    at scala.collection.TraversableOnce$class.to(TraversableOnce.scala:273)
    at scala.collection.AbstractIterator.to(Iterator.scala:1157)
    at scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:265)
    at scala.collection.AbstractIterator.toBuffer(Iterator.scala:1157)
    at scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:252)
    at scala.collection.AbstractIterator.toArray(Iterator.scala:1157)
    at org.apache.spark.rdd.RDD$anonfun$4.apply(RDD.scala:608)
    at org.apache.spark.rdd.RDD$anonfun$4.apply(RDD.scala:608)
    at org.apache.spark.SparkContext$anonfun$runJob$4.apply(SparkContext.scala:884)
    at org.apache.spark.SparkContext$anonfun$runJob$4.apply(SparkContext.scala:884)
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:109)
    at org.apache.spark.scheduler.Task.run(Task.scala:53)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:205)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)
Caused by: com.datastax.driver.core.exceptions.InvalidQueryException: role cannot be restricted by more than one relation if it includes an Equal
    at com.datastax.driver.core.exceptions.InvalidQueryException.copy(InvalidQueryException.java:35)
    at com.datastax.driver.core.DefaultResultSetFuture.extractCauseFromExecutionException(DefaultResultSetFuture.java:256)
    at com.datastax.driver.core.AbstractSession.prepare(AbstractSession.java:91)
    at com.datastax.spark.connector.cql.PreparedStatementCache$.prepareStatement(PreparedStatementCache.scala:45)
    at com.datastax.spark.connector.cql.SessionProxy.invoke(SessionProxy.scala:28)
    at com.sun.proxy.$Proxy8.prepare(Unknown Source)
    at com.datastax.spark.connector.rdd.CassandraRDD.createStatement(CassandraRDD.scala:293)
    ... 27 more
Caused by: com.datastax.driver.core.exceptions.InvalidQueryException: role cannot be restricted by more than one relation if it includes an Equal
    at com.datastax.driver.core.Responses$Error.asException(Responses.java:97)
    at com.datastax.driver.core.SessionManager$1.apply(SessionManager.java:156)
    at com.datastax.driver.core.SessionManager$1.apply(SessionManager.java:131)
    at com.google.common.util.concurrent.Futures$1.apply(Futures.java:711)
    at com.google.common.util.concurrent.Futures$ChainingListenableFuture.run(Futures.java:849)
    ... 3 more
14/09/23 13:46:53 WARN scheduler.TaskSetManager: Lost TID 0 (task 0.0:0)
14/09/23 13:46:53 WARN scheduler.TaskSetManager: Loss was due to java.io.IOException
java.io.IOException: Exception during preparation of SELECT "role", "id", "fname", "lname" FROM "tester"."empbyrole" WHERE token("role") > -5709068081826432029 AND token("role") <= -5491279024053142424 AND role=? ALLOW FILTERING: role cannot be restricted by more than one relation if it includes an Equal
    at com.datastax.spark.connector.rdd.CassandraRDD.createStatement(CassandraRDD.scala:310)
    at com.datastax.spark.connector.rdd.CassandraRDD.com$datastax$spark$connector$rdd$CassandraRDD$fetchTokenRange(CassandraRDD.scala:317)
    at com.datastax.spark.connector.rdd.CassandraRDD$anonfun$13.apply(CassandraRDD.scala:338)
    at com.datastax.spark.connector.rdd.CassandraRDD$anonfun$13.apply(CassandraRDD.scala:338)
    at scala.collection.Iterator$anon$13.hasNext(Iterator.scala:371)
    at com.datastax.spark.connector.util.CountingIterator.hasNext(CountingIterator.scala:10)
    at scala.collection.Iterator$anon$11.hasNext(Iterator.scala:327)
    at scala.collection.Iterator$class.foreach(Iterator.scala:727)
    at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
    at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:48)
    at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:103)
    at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:47)
    at scala.collection.TraversableOnce$class.to(TraversableOnce.scala:273)
    at scala.collection.AbstractIterator.to(Iterator.scala:1157)
    at scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:265)
    at scala.collection.AbstractIterator.toBuffer(Iterator.scala:1157)
    at scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:252)
    at scala.collection.AbstractIterator.toArray(Iterator.scala:1157)
    at org.apache.spark.rdd.RDD$anonfun$4.apply(RDD.scala:608)
    at org.apache.spark.rdd.RDD$anonfun$4.apply(RDD.scala:608)
    at org.apache.spark.SparkContext$anonfun$runJob$4.apply(SparkContext.scala:884)
    at org.apache.spark.SparkContext$anonfun$runJob$4.apply(SparkContext.scala:884)
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:109)
    at org.apache.spark.scheduler.Task.run(Task.scala:53)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:205)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)
14/09/23 13:46:53 ERROR scheduler.TaskSetManager: Task 0.0:0 failed 1 times; aborting job
14/09/23 13:46:53 INFO scheduler.TaskSchedulerImpl: Removed TaskSet 0.0, whose tasks have all completed, from pool 
14/09/23 13:46:53 INFO scheduler.DAGScheduler: Failed to run toArray at App.java:65
Exception in thread "main" org.apache.spark.SparkException: Job aborted: Task 0.0:0 failed 1 times (most recent failure: Exception failure: java.io.IOException: Exception during preparation of SELECT "role", "id", "fname", "lname" FROM "tester"."empbyrole" WHERE token("role") > -5709068081826432029 AND token("role") <= -5491279024053142424 AND role=? ALLOW FILTERING: role cannot be restricted by more than one relation if it includes an Equal)
    at org.apache.spark.scheduler.DAGScheduler$anonfun$org$apache$spark$scheduler$DAGScheduler$abortStage$1.apply(DAGScheduler.scala:1020)
    at org.apache.spark.scheduler.DAGScheduler$anonfun$org$apache$spark$scheduler$DAGScheduler$abortStage$1.apply(DAGScheduler.scala:1018)
    at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
    at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
    at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$abortStage(DAGScheduler.scala:1018)
    at org.apache.spark.scheduler.DAGScheduler$anonfun$processEvent$10.apply(DAGScheduler.scala:604)
    at org.apache.spark.scheduler.DAGScheduler$anonfun$processEvent$10.apply(DAGScheduler.scala:604)
    at scala.Option.foreach(Option.scala:236)
    at org.apache.spark.scheduler.DAGScheduler.processEvent(DAGScheduler.scala:604)
    at org.apache.spark.scheduler.DAGScheduler$anonfun$starthttps://github.com/datastax/spark-cassandra-connector$anonHe descubierto cómo usar las declaraciones directas de CQL, ya que anteriormente hice una pregunta sobre eso aquí:$anonfun$receive$1.applyOrElse(DAGScheduler.scala:190)
    at akka.actor.ActorCell.receiveMessage(ActorCell.scala:498)
    at akka.actor.ActorCell.invoke(ActorCell.scala:456)
    at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:237)
    at akka.dispatch.Mailbox.run(Mailbox.scala:219)
    at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:386)
    at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
    at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
    at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
    at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
14/09/23 13:46:53 INFO cql.CassandraConnector: Disconnected from Cassandra cluster: Test Cluster

Sé que mi error es específicamente en esta sección:

JavaRDD<String> rdd = javaFunctions(sc).cassandraTable("tester", "empbyrole", Person.class)
                .where("role=?", "IT Engineer").map(new Function<Person, String>() {
                    @Override
                    public String call(Person person) throws Exception {
                        return person.toString();
                    }
                });

Cuando quito el.where(), funciona. Pero dice específicamente en github que debería poder ejecutar las funciones .where y .map respectivamente. ¿Alguien tiene algún tipo de razonamiento para esto? o solución? Gracias.

editar Me sale el error cuando uso esta declaración en su lugar:

JavaRDD<String> rdd = javaFunctions(sc).cassandraTable("tester", "empbyrole", Person.class)
                .where("id=?", "1").map(new Function<Person, String>() {
                    @Override
                    public String call(Person person) throws Exception {
                        return person.toString();
                    }
                });

No tengo idea de por qué funciona esta opción, pero no el resto de mis variaciones. Aquí están las declaraciones que ejecuté en mi cql para que sepa cómo se ve mi espacio de teclas:

    session.execute("DROP KEYSPACE IF EXISTS tester");
    session.execute("CREATE KEYSPACE tester WITH replication = {'class': 'SimpleStrategy', 'replication_factor': 3}");
    session.execute("CREATE TABLE tester.emp (id INT PRIMARY KEY, fname TEXT, lname TEXT, role TEXT)");
    session.execute("CREATE TABLE tester.empByRole (id INT, fname TEXT, lname TEXT, role TEXT, PRIMARY KEY (role,id))");
    session.execute("CREATE TABLE tester.dept (id INT PRIMARY KEY, dname TEXT)");       

    session.execute(
              "INSERT INTO tester.emp (id, fname, lname, role) " +
              "VALUES (" +
                  "0001," +
                  "'Angel'," +
                  "'Pay'," +
                  "'IT Engineer'" +
                  ");");
    session.execute(
              "INSERT INTO tester.emp (id, fname, lname, role) " +
              "VALUES (" +
                  "0002," +
                  "'John'," +
                  "'Doe'," +
                  "'IT Engineer'" +
                  ");");
    session.execute(
              "INSERT INTO tester.emp (id, fname, lname, role) " +
              "VALUES (" +
                  "0003," +
                  "'Jane'," +
                  "'Doe'," +
                  "'IT Analyst'" +
                  ");");
    session.execute(
          "INSERT INTO tester.empByRole (id, fname, lname, role) " +
          "VALUES (" +
              "0001," +
              "'Angel'," +
              "'Pay'," +
              "'IT Engineer'" +
              ");");
    session.execute(
              "INSERT INTO tester.empByRole (id, fname, lname, role) " +
              "VALUES (" +
                  "0002," +
                  "'John'," +
                  "'Doe'," +
                  "'IT Engineer'" +
                  ");");
    session.execute(
              "INSERT INTO tester.empByRole (id, fname, lname, role) " +
              "VALUES (" +
                  "0003," +
                  "'Jane'," +
                  "'Doe'," +
                  "'IT Analyst'" +
                  ");");
        session.execute(
              "INSERT INTO tester.dept (id, dname) " +
              "VALUES (" +
                  "1553," +
                  "'Commerce'" +
                  ");");