My first scala from Spark system: word count

[root@john1 john]# cd /var/lib/hadoop-hdfs
[root@john1 hadoop-hdfs]# sudo -u hdfs spark-shell --master yarn --deploy-mode client
Setting default log level to "WARN".
To adjust logging level use sc.setLogLevel(newLevel).
Welcome to
      ____              __
     / __/__  ___ _____/ /__
    _\ \/ _ \/ _ `/ __/  '_/
   /___/ .__/\_,_/_/ /_/\_\   version 1.6.0
      /_/

Using Scala version 2.10.5 (Java HotSpot(TM) 64-Bit Server VM, Java 1.7.0_67)
Type in expressions to have them evaluated.
Type :help for more information.
Spark context available as sc (master = yarn-client, app id = application_1486166793688_0005).
17/02/06 16:13:53 WARN metastore.ObjectStore: Version information not found in metastore. hive.metastore.schema.verification is not enabled so recording the schema version 1.1.0
17/02/06 16:13:54 WARN metastore.ObjectStore: Failed to get database default, returning NoSuchObjectException
SQL context available as sqlContext.

scala> val logFile = "hdfs://john1.dg:8020/johnz/text/test.txt"
logFile: String = hdfs://john1.dg:8020/johnz/text/test.txt

scala> val file = sc.textFile(logFile)
file: org.apache.spark.rdd.RDD[String] = hdfs://john1.dg:8020/johnz/text/test.txt MapPartitionsRDD[1] at textFile at <console>:29

scala> val counts = file.flatMap(_.split(" ")).map(word => (word,1)).reduceByKey(_ + _)
counts: org.apache.spark.rdd.RDD[(String, Int)] = ShuffledRDD[4] at reduceByKey at <console>:31

scala> counts.collect()
res0: Array[(String, Int)] = Array((executes,1), (is,1), (expressive,1), (real,1), ((clustered),1), ("",1), (apache,1), (computing,1), (fast,,1), (job,1), (environment.,1), (spark,1), (a,1), (in,1), (which,1), (extremely,1), (distributed,1), (time,1), (and,1), (system,1))