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Spark Submit

By September 6, 2017

The following is a simple example of submitting a Spark job that uses an existing jar all users have access to. It estimates Pi, and the number at the end is the number of iterations it uses (more iterations = more accurate).

cd /usr/hdp/current/spark2-client
spark-submit \
   --class org.apache.spark.examples.SparkPi \
   --master yarn \
   --queue <your_queue> \
examples/jars/spark-examples*.jar 10

Gradle is a popular build tool for Java and Scala. The following example is useful if you may be getting code from bitbucket, github, etc. This code can be downloaded and built by logging on to flux-hadoop-login and running:

git clone https://bitbucket.org/umarcts/spark-examples
cd spark-examples
./gradlew jar

The last command, “./gradlew jar”, will download all dependencies, compile the code, run tests, and package all of the code into a Java ARchive (JAR). This JAR is submitted to the cluster to run a job. For example, the AverageNGramLength job can be launched by running:

spark-submit \
   --class com.alectenharmsel.examples.spark.AverageNGramLength \
   --master yarn \
   --executor-memory 3g \
   --num-executors 35 \
 build/libs/spark-examples-*-all.jar /var/ngrams ngrams-out

The output will be located in your home directory in a directory called ‘ngrams-out’, and can be viewed by running:

hdfs dfs -cat ngrams-out/* | tail -5

The output should look like this:

spark output

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