Jas Jas - 3 months ago 34
Scala Question

How to load local file in sc.textFile, instead of HDFS

I'm following the great spark tutorial

so i'm trying at 46m:00s to load the

README.md
but fail to what i'm doing is this:

$ sudo docker run -i -t -h sandbox sequenceiq/spark:1.1.0 /etc/bootstrap.sh -bash
bash-4.1# cd /usr/local/spark-1.1.0-bin-hadoop2.4
bash-4.1# ls README.md
README.md
bash-4.1# ./bin/spark-shell
scala> val f = sc.textFile("README.md")
14/12/04 12:11:14 INFO storage.MemoryStore: ensureFreeSpace(164073) called with curMem=0, maxMem=278302556
14/12/04 12:11:14 INFO storage.MemoryStore: Block broadcast_0 stored as values in memory (estimated size 160.2 KB, free 265.3 MB)
f: org.apache.spark.rdd.RDD[String] = README.md MappedRDD[1] at textFile at <console>:12
scala> val wc = f.flatMap(l => l.split(" ")).map(word => (word, 1)).reduceByKey(_ + _)
org.apache.hadoop.mapred.InvalidInputException: Input path does not exist: hdfs://sandbox:9000/user/root/README.md
at org.apache.hadoop.mapred.FileInputFormat.singleThreadedListStatus(FileInputFormat.java:285)


how can I load that
README.md
?

Answer

Try explicitly specify sc.textFile("file:///path to the file/"). The error occurs when Hadoop environment is set.

SparkContext.textFile internally calls org.apache.hadoop.mapred.FileInputFormat.getSplits, which in turn uses org.apache.hadoop.fs.getDefaultUri if schema is absent. This method reads "fs.defaultFS" parameter of Hadoop conf. If you set HADOOP_CONF_DIR environment variable, the parameter is usually set as "hdfs://..."; otherwise "file://".

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