title: Spark spark-submit --jars arguments wants comma list, how to declare a directory of jars?
body: <p>In <a href="http://spark.apache.org/docs/latest/submitting-applications.html#advanced-dependency-management" rel="noreferrer">Submitting Applications in the Spark docs, as of 1.6.0 and earlier</a>, it's not clear how to specify the --jars argument, as it's apparently not a colon-separated classpath not a directory expansion.</p>
  
  <p>The docs say "Path to a bundled jar including your application and all dependencies. The URL must be globally visible inside of your cluster, for instance, an hdfs:// path or a file:// path that is present on all nodes."</p>
  
  <blockquote>
    <p>Question: What are all the options for submitting a classpath with
    --jars in the spark-submit script in $SPARK_HOME/bin? Anything undocumented that could be submitted as an improvement for docs?</p>
  </blockquote>
  
  <p>I ask because when I was testing --jars today, we had to explicitly provide a path to each jar:</p>
  
  <pre><code>/usr/local/spark/bin/spark-submit --class jpsgcs.thold.PipeLinkageData ---jars=local:/usr/local/spark/jars/groovy-all-2.3.3.jar,local:/usr/local/spark/jars/guava-14.0.1.jar,local:/usr/local/spark/jars/jopt-simple-4.6.jar,local:/usr/local/spark/jars/jpsgcs-core-1.0.8-2.jar,local:/usr/local/spark/jars/jpsgcs-pipe-1.0.6-7.jar /usr/local/spark/jars/thold-0.0.1-1.jar
  </code></pre>
  
  <p>We are choosing to pre-populate the cluster with all the jars in /usr/local/spark/jars on each worker, it seemed that if no local:/ file:/ or hdfs: was supplied, then the default is file:/ and the driver makes the jars available on a webserver run by the driver. I chose local, as above.</p>
  
  <p>And it seems that we do not need to put the main jar in the --jars argument, I have not tested yet if other classes in the final argument (application-jar arg per docs, i.e. /usr/local/spark/jars/thold-0.0.1-1.jar) are shipped to workers, or if I need to put the application-jar in the --jars path to get classes not named after --class to be seen.</p>
  
  <p>(And granted with Spark standalone mode using --deploy-mode client, you also have to put a copy of the driver on each worker but you don't know up front which worker will run the driver)</p>