python - What is the difference between spark-submit and pyspark?

Question

If I start up pyspark and then run this command:

import my_script; spark = my_script.Sparker(sc); spark.collapse('./data/')

Everything is A-ok. If, however, I try to do the same thing through the commandline and spark-submit, I get an error:

Command: /usr/local/spark/bin/spark-submit my_script.py collapse ./data/
  File "/usr/local/spark/python/pyspark/rdd.py", line 352, in func
    return f(iterator)
  File "/usr/local/spark/python/pyspark/rdd.py", line 1576, in combineLocally
    merger.mergeValues(iterator)
  File "/usr/local/spark/python/pyspark/shuffle.py", line 245, in mergeValues
    for k, v in iterator:
  File "/.../my_script.py", line 173, in _json_args_to_arr
    js = cls._json(line)
RuntimeError: uninitialized staticmethod object

my_script:

...
if __name__ == "__main__":
    args = sys.argv[1:]
    if args[0] == 'collapse':
        directory = args[1]
        from pyspark import SparkContext
        sc = SparkContext(appName="Collapse")
        spark = Sparker(sc)
        spark.collapse(directory)
        sc.stop()

Why is this happening? What's the difference between running pyspark and running spark-submit that would cause this divergence? And how can I make this work in spark-submit?

EDIT: I tried running this from the bash shell by doing pyspark my_script.py collapse ./data/ and I got the same error. The only time when everything works is when I am in a python shell and import the script.

Answer 1

1. If you built a spark application, you need to use spark-submit to run the application

   • The code can be written either in python/scala

   • The mode can be either local/cluster

2. If you just want to test/run few individual commands, you can use the shell provided by spark

   • pyspark (for spark in python)
   • spark-shell (for spark in scala)