[SPARK-12695] java.lang.ClassCastException: [B cannot be cast to java.lang.String

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 1.6.0
• Component/s: PySpark
• Assignee: Unassigned
• Reporter: eugeny birukov
• Created: 07/Jan/16 17:44
• Updated: 29/Jan/16 19:25
• Resolved: 29/Jan/16 19:25

Description

I process kinesis stream in python code:

stream = KinesisUtils.createStream(ssc, appName, streamName, endpointUrl, regionName, InitialPositionInStream.LATEST, 30)

stream.map(lambda line: str(line)).foreachRDD(process)

def process(time, rdd):
sqlContext = SQLContext.getOrCreate(rdd.context)
t = sqlContext.read.json(rdd)

run and get exception

org.apache.spark.SparkException: An exception was raised by Python:
Traceback (most recent call last):
File "/usr/local/spark/python/lib/pyspark.zip/pyspark/streaming/util.py", line 65, in call
r = self.func(t, *rdds)
File "/usr/local/spark-1.6.0-bin-hadoop2.4/bin/kinesis_test.py", line 26, in process
t = sqlContext.read.json(rdd.map(lambda line: str(line)))
File "/usr/local/spark/python/lib/pyspark.zip/pyspark/sql/readwriter.py", line 180, in json
return self._df(self._jreader.json(path._jrdd))
File "/usr/local/spark/python/lib/py4j-0.9-src.zip/py4j/java_gateway.py", line 813, in _call_
answer, self.gateway_client, self.target_id, self.name)
File "/usr/local/spark/python/lib/pyspark.zip/pyspark/sql/utils.py", line 45, in deco
return f(*a, **kw)
File "/usr/local/spark/python/lib/py4j-0.9-src.zip/py4j/protocol.py", line 308, in get_return_value
format(target_id, ".", name), value)
Py4JJavaError: An error occurred while calling o165.json.
: org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 1.0 failed 1 times, most recent failure: Lost task 0.0 in stage 1.0 (TID 1, localhost): java.lang.ClassCastException: [B cannot be cast to java.lang.String
at org.apache.spark.sql.execution.datasources.json.InferSchema$$anonfun$1$$anonfun$apply$1.apply(InferSchema.scala:53)
at scala.collection.Iterator$$anon$11.next(Iterator.scala:328)
at scala.collection.Iterator$class.foreach(Iterator.scala:727)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
at scala.collection.TraversableOnce$class.foldLeft(TraversableOnce.scala:144)
at scala.collection.AbstractIterator.foldLeft(Iterator.scala:1157)
at scala.collection.TraversableOnce$class.aggregate(TraversableOnce.scala:201)
at scala.collection.AbstractIterator.aggregate(Iterator.scala:1157)
at org.apache.spark.rdd.RDD$$anonfun$treeAggregate$1$$anonfun$23.apply(RDD.scala:1121)
at org.apache.spark.rdd.RDD$$anonfun$treeAggregate$1$$anonfun$23.apply(RDD.scala:1121)
at org.apache.spark.rdd.RDD$$anonfun$treeAggregate$1$$anonfun$24.apply(RDD.scala:1122)
at org.apache.spark.rdd.RDD$$anonfun$treeAggregate$1$$anonfun$24.apply(RDD.scala:1122)
at org.apache.spark.rdd.RDD$$anonfun$mapPartitions$1$$anonfun$apply$20.apply(RDD.scala:710)
at org.apache.spark.rdd.RDD$$anonfun$mapPartitions$1$$anonfun$apply$20.apply(RDD.scala:710)
at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:306)
at org.apache.spark.rdd.RDD.iterator(RDD.scala:270)
at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:306)
at org.apache.spark.rdd.RDD.iterator(RDD.scala:270)
at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:73)
at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:41)
at org.apache.spark.scheduler.Task.run(Task.scala:89)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:213)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

Driver stacktrace:
at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1431)
....

in java same code has no exceptions

streams.map(x -> new String( x ) )
.foreachRDD((JavaRDD<String> rdd) ->

{ SQLContext sqlContext = SQLContext.getOrCreate(rdd.context()); sqlContext.read().json(rdd).registerTempTable("jtable"); DataFrame df = sqlContext.sql("select count(appName), appName, type from jtable group by appName, type order by appName "); df.show(200); }

);

Issue Links

• duplicates: SPARK-13082 sqlCtx.real.json() doesn't work with PythonRDD