Apache Spark: SparkFiles.get(fileName.txt) - Unable to retrieve the file contents from SparkContext

Question

I used SparkContext.addFile("hdfs://host:54310/spark/fileName.txt") and added a file to SparkContext. I verified its presence using org.apache.spark.SparkFiles.get(fileName.txt). It showed an absolute path, something like /tmp/spark-xxxx/userFiles-xxxx/fileName.txt.

Now I want to read that file from the above given absolute path location from SparkContext. I tried sc.textFile(org.apache.spark.SparkFiles.get("fileName.txt")).collect().foreach(println) It considers the path returned by SparkFiles.get() as a HDFS path, which is incorrect.

I searched extensively to find any helpful reads on this, but ran out of luck.

Is there anything wrong in the approach? Any help is really appreciated.

Here is the code and the outcome:

scala> sc.addFile("hdfs://localhost:54310/spark/fileName.txt")

scala> org.apache.spark.SparkFiles.get("fileName.txt")
res23: String = /tmp/spark-3646b5fe-0a67-4a16-bd25-015cc73533cd/userFiles-a7d54640-fab2-4dfa-a94f-7de6f74a0764/fileName.txt

scala> sc.textFile(org.apache.spark.SparkFiles.get("fileName.txt")).collect().foreach(println)
org.apache.hadoop.mapred.InvalidInputException: Input path does not exist: hdfs://localhost:54310/tmp/spark-3646b5fe-0a67-4a16-bd25-015cc73533cd/userFiles-a7d54640-fab2-4dfa-a94f-7de6f74a0764/fileName.txt
  at org.apache.hadoop.mapred.FileInputFormat.singleThreadedListStatus(FileInputFormat.java:287)
  at org.apache.hadoop.mapred.FileInputFormat.listStatus(FileInputFormat.java:229)
  at org.apache.hadoop.mapred.FileInputFormat.getSplits(FileInputFormat.java:315)
  at org.apache.spark.rdd.HadoopRDD.getPartitions(HadoopRDD.scala:200)
  at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:253)
  at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:251)
  at scala.Option.getOrElse(Option.scala:121)
  at org.apache.spark.rdd.RDD.partitions(RDD.scala:251)
  at org.apache.spark.rdd.MapPartitionsRDD.getPartitions(MapPartitionsRDD.scala:35)
  at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:253)
  at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:251)
  at scala.Option.getOrElse(Option.scala:121)
  at org.apache.spark.rdd.RDD.partitions(RDD.scala:251)
  at org.apache.spark.SparkContext.runJob(SparkContext.scala:2092)
  at org.apache.spark.rdd.RDD$$anonfun$collect$1.apply(RDD.scala:939)
  at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:151)
  at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:112)
  at org.apache.spark.rdd.RDD.withScope(RDD.scala:363)
  at org.apache.spark.rdd.RDD.collect(RDD.scala:938)
  ... 49 elided

Answer 1

Refer to local file using the "file://" syntax.

sc.textFile("file://" + org.apache.spark.SparkFiles.get("fileName.txt"))
.collect()
.foreach(println)