Spark Structured streaming enriched from Cassandra












0















I stream data from Kafka with structured streaming



  val df = spark
.readStream
.format("kafka")
.option("kafka.bootstrap.servers", "localhost:9092")
.option("enable.auto.commit", false)
.option("auto.offset.reset", "earliest")
.option("group.id", UUID.randomUUID().toString)
.option("subscribe", "test")
.load()


and then try to join it with a Cassandra table



val d = df.select(from_json(col("value").cast("string"), schema).cast("string").alias("url"))
.rdd.joinWithCassandraTable[(String, String, String)]("analytics", "nlp2", SomeColumns("url", "ner", "sentiment"), SomeColumns("url"))
.toDS()
.writeStream
.format("console") // <-- use ConsoleSink
.option("truncate", false)
.option("numRows", 10)
.trigger(Trigger.ProcessingTime(5 seconds))
.queryName("rate-console")
.start
.awaitTermination()


but i get, when i try to convert data frame to rdd, any ideas why?



Exception in thread "main" org.apache.spark.sql.AnalysisException: Queries with streaming sources must be executed with writeStream.start();;
kafka
at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$.org$apache$spark$sql$catalyst$analysis$UnsupportedOperationChecker$$throwError(UnsupportedOperationChecker.scala:297)
at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$$anonfun$checkForBatch$1.apply(UnsupportedOperationChecker.scala:36)
at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$$anonfun$checkForBatch$1.apply(UnsupportedOperationChecker.scala:34)
at org.apache.spark.sql.catalyst.trees.TreeNode.foreachUp(TreeNode.scala:127)









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    0















    I stream data from Kafka with structured streaming



      val df = spark
    .readStream
    .format("kafka")
    .option("kafka.bootstrap.servers", "localhost:9092")
    .option("enable.auto.commit", false)
    .option("auto.offset.reset", "earliest")
    .option("group.id", UUID.randomUUID().toString)
    .option("subscribe", "test")
    .load()


    and then try to join it with a Cassandra table



    val d = df.select(from_json(col("value").cast("string"), schema).cast("string").alias("url"))
    .rdd.joinWithCassandraTable[(String, String, String)]("analytics", "nlp2", SomeColumns("url", "ner", "sentiment"), SomeColumns("url"))
    .toDS()
    .writeStream
    .format("console") // <-- use ConsoleSink
    .option("truncate", false)
    .option("numRows", 10)
    .trigger(Trigger.ProcessingTime(5 seconds))
    .queryName("rate-console")
    .start
    .awaitTermination()


    but i get, when i try to convert data frame to rdd, any ideas why?



    Exception in thread "main" org.apache.spark.sql.AnalysisException: Queries with streaming sources must be executed with writeStream.start();;
    kafka
    at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$.org$apache$spark$sql$catalyst$analysis$UnsupportedOperationChecker$$throwError(UnsupportedOperationChecker.scala:297)
    at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$$anonfun$checkForBatch$1.apply(UnsupportedOperationChecker.scala:36)
    at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$$anonfun$checkForBatch$1.apply(UnsupportedOperationChecker.scala:34)
    at org.apache.spark.sql.catalyst.trees.TreeNode.foreachUp(TreeNode.scala:127)









    share|improve this question

























      0












      0








      0








      I stream data from Kafka with structured streaming



        val df = spark
      .readStream
      .format("kafka")
      .option("kafka.bootstrap.servers", "localhost:9092")
      .option("enable.auto.commit", false)
      .option("auto.offset.reset", "earliest")
      .option("group.id", UUID.randomUUID().toString)
      .option("subscribe", "test")
      .load()


      and then try to join it with a Cassandra table



      val d = df.select(from_json(col("value").cast("string"), schema).cast("string").alias("url"))
      .rdd.joinWithCassandraTable[(String, String, String)]("analytics", "nlp2", SomeColumns("url", "ner", "sentiment"), SomeColumns("url"))
      .toDS()
      .writeStream
      .format("console") // <-- use ConsoleSink
      .option("truncate", false)
      .option("numRows", 10)
      .trigger(Trigger.ProcessingTime(5 seconds))
      .queryName("rate-console")
      .start
      .awaitTermination()


      but i get, when i try to convert data frame to rdd, any ideas why?



      Exception in thread "main" org.apache.spark.sql.AnalysisException: Queries with streaming sources must be executed with writeStream.start();;
      kafka
      at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$.org$apache$spark$sql$catalyst$analysis$UnsupportedOperationChecker$$throwError(UnsupportedOperationChecker.scala:297)
      at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$$anonfun$checkForBatch$1.apply(UnsupportedOperationChecker.scala:36)
      at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$$anonfun$checkForBatch$1.apply(UnsupportedOperationChecker.scala:34)
      at org.apache.spark.sql.catalyst.trees.TreeNode.foreachUp(TreeNode.scala:127)









      share|improve this question














      I stream data from Kafka with structured streaming



        val df = spark
      .readStream
      .format("kafka")
      .option("kafka.bootstrap.servers", "localhost:9092")
      .option("enable.auto.commit", false)
      .option("auto.offset.reset", "earliest")
      .option("group.id", UUID.randomUUID().toString)
      .option("subscribe", "test")
      .load()


      and then try to join it with a Cassandra table



      val d = df.select(from_json(col("value").cast("string"), schema).cast("string").alias("url"))
      .rdd.joinWithCassandraTable[(String, String, String)]("analytics", "nlp2", SomeColumns("url", "ner", "sentiment"), SomeColumns("url"))
      .toDS()
      .writeStream
      .format("console") // <-- use ConsoleSink
      .option("truncate", false)
      .option("numRows", 10)
      .trigger(Trigger.ProcessingTime(5 seconds))
      .queryName("rate-console")
      .start
      .awaitTermination()


      but i get, when i try to convert data frame to rdd, any ideas why?



      Exception in thread "main" org.apache.spark.sql.AnalysisException: Queries with streaming sources must be executed with writeStream.start();;
      kafka
      at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$.org$apache$spark$sql$catalyst$analysis$UnsupportedOperationChecker$$throwError(UnsupportedOperationChecker.scala:297)
      at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$$anonfun$checkForBatch$1.apply(UnsupportedOperationChecker.scala:36)
      at org.apache.spark.sql.catalyst.analysis.UnsupportedOperationChecker$$anonfun$checkForBatch$1.apply(UnsupportedOperationChecker.scala:34)
      at org.apache.spark.sql.catalyst.trees.TreeNode.foreachUp(TreeNode.scala:127)






      apache-spark cassandra






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      asked Nov 16 '18 at 15:46









      DimaDima

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          As the error message says, start need to be invoked with parenthesis as below:



           val d = df.select(from_json(col("value").cast("string"), schema).cast("string").alias("url"))
          .rdd.joinWithCassandraTable[(String, String, String)]("analytics", "nlp2", SomeColumns("url", "ner", "sentiment"), SomeColumns("url"))
          .toDS()
          .writeStream
          .format("console") // <-- use ConsoleSink
          .option("truncate", false)
          .option("numRows", 10)
          .trigger(Trigger.ProcessingTime(5 seconds))
          .queryName("rate-console")
          .start()
          .awaitTermination()





          share|improve this answer























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            1 Answer
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            0














            As the error message says, start need to be invoked with parenthesis as below:



             val d = df.select(from_json(col("value").cast("string"), schema).cast("string").alias("url"))
            .rdd.joinWithCassandraTable[(String, String, String)]("analytics", "nlp2", SomeColumns("url", "ner", "sentiment"), SomeColumns("url"))
            .toDS()
            .writeStream
            .format("console") // <-- use ConsoleSink
            .option("truncate", false)
            .option("numRows", 10)
            .trigger(Trigger.ProcessingTime(5 seconds))
            .queryName("rate-console")
            .start()
            .awaitTermination()





            share|improve this answer




























              0














              As the error message says, start need to be invoked with parenthesis as below:



               val d = df.select(from_json(col("value").cast("string"), schema).cast("string").alias("url"))
              .rdd.joinWithCassandraTable[(String, String, String)]("analytics", "nlp2", SomeColumns("url", "ner", "sentiment"), SomeColumns("url"))
              .toDS()
              .writeStream
              .format("console") // <-- use ConsoleSink
              .option("truncate", false)
              .option("numRows", 10)
              .trigger(Trigger.ProcessingTime(5 seconds))
              .queryName("rate-console")
              .start()
              .awaitTermination()





              share|improve this answer


























                0












                0








                0







                As the error message says, start need to be invoked with parenthesis as below:



                 val d = df.select(from_json(col("value").cast("string"), schema).cast("string").alias("url"))
                .rdd.joinWithCassandraTable[(String, String, String)]("analytics", "nlp2", SomeColumns("url", "ner", "sentiment"), SomeColumns("url"))
                .toDS()
                .writeStream
                .format("console") // <-- use ConsoleSink
                .option("truncate", false)
                .option("numRows", 10)
                .trigger(Trigger.ProcessingTime(5 seconds))
                .queryName("rate-console")
                .start()
                .awaitTermination()





                share|improve this answer













                As the error message says, start need to be invoked with parenthesis as below:



                 val d = df.select(from_json(col("value").cast("string"), schema).cast("string").alias("url"))
                .rdd.joinWithCassandraTable[(String, String, String)]("analytics", "nlp2", SomeColumns("url", "ner", "sentiment"), SomeColumns("url"))
                .toDS()
                .writeStream
                .format("console") // <-- use ConsoleSink
                .option("truncate", false)
                .option("numRows", 10)
                .trigger(Trigger.ProcessingTime(5 seconds))
                .queryName("rate-console")
                .start()
                .awaitTermination()






                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered Nov 17 '18 at 9:35









                Lakshman BattiniLakshman Battini

                1,099315




                1,099315






























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