Easy to use pure-Python scheduler.

Overview¶

With the increasing amount of data to be treated, efficient scaling strategies are necessary. This observation made me start ‘hopla’ which provides:

a scheduler that produces human readable outputs.
a converter that enables to execute kilometer command lines
workers that enable local or cluster executions.

Usage¶

The proposed module has been currently developped to execute Python scripts. Consider the following demonstration script that lists an input folder (the latter is available in the ‘hopla.demo.my_ls_script’ module):

# System import
import argparse
import os

# Parameters to keep trace
__hopla__ = ["directory", "files"]

def is_directory(dirarg):
    """ Type for argparse - checks that directory exists.
    """
    if not os.path.isdir(dirarg):
        raise argparse.ArgumentError(
            "The directory '{0}' does not exist!".format(dirarg))
    return dirarg

parser = argparse.ArgumentParser(description="List a directory.")
parser.add_argument(
    "-d", "--dir", dest="dir", required=True, metavar="PATH",
    help="a valid directory to be listed.", type=is_directory)
parser.add_argument(
    "-v", "--verbose", dest="verbose", type=int, choices=[0, 1, 2],
    default=0,
    help="increase the verbosity level: 0 silent, [1, 2] verbose.")
args = parser.parse_args()

directory = args.dir
files = os.listdir(directory)
if args.verbose > 0:
    print(files)

Note the ‘__hopla__’ list that specifies which parameters will be dispalyed in the scheduler execution log. This mechanism is usefull to keep trace of important script elements (ie., the outputs). The scaled execution of this script on two CPUs is realized using a simple call:

from hopla.converter import hopla
import hopla.demo as demo

apath = os.path.abspath(os.path.dirname(__file__))
script = os.path.join(os.path.dirname(demo.__file__),
                      "my_ls_script.py")
status, exitcodes = hopla(
    script, hopla_iterative_kwargs=["d"], verbose=0,
    d=[apath, apath, apath], hopla_verbose=1, hopla_cpus=2)
for job_name, exitcode in exitcodes.items():
    if exitcode > 0:
        pprint(status[job_name]["info"])

After the execution call (through the hopla function), exit codes are inspected. The ‘hopla_verbose’ has been set to one, some logging information has been displayed:

2015-11-06 13:24:22,733 - INFO - Using 'hopla' version '1.0.0'.
2015-11-06 13:24:22,733 - INFO - For exitcode values:
    = 0 - no error was produced.
    > 0 - the process had an error, and exited with that code.
    < 0 - the process was killed with a signal of -1 * exitcode.
2015-11-06 13:24:22,838 - INFO - job_0.directory = /home/ag239446/git/
    hopla/hopla/test
2015-11-06 13:24:22,839 - INFO - job_0.files = ['__pycache__', 'test.py~',
    'test.pyc', 'test.py']
2015-11-06 13:24:22,839 - INFO - job_0.cmd = ['/home/ag239446/git/hopla/
    hopla/demo/my_ls_script.py', '-d', '/home/ag239446/git/hopla/hopla/
    test', '--verbose', '0']
2015-11-06 13:24:22,839 - INFO - job_0.exitcode = 0
2015-11-06 13:24:22,839 - INFO - job_1.directory = /home/ag239446/git/
    hopla/hopla/test
2015-11-06 13:24:22,839 - INFO - job_1.files = ['__pycache__', 'test.py~',
    'test.pyc', 'test.py']
2015-11-06 13:24:22,840 - INFO - job_1.cmd = ['/home/ag239446/git/hopla/
    hopla/demo/my_ls_script.py', '-d', '/home/ag239446/git/hopla/hopla/
    test', '--verbose', '0']
2015-11-06 13:24:22,840 - INFO - job_1.exitcode = 0
2015-11-06 13:24:22,842 - INFO - job_2.directory = /home/ag239446/git/
    hopla/hopla/test
2015-11-06 13:24:22,842 - INFO - job_2.files = ['__pycache__', 'test.py~',
    'test.pyc', 'test.py']
2015-11-06 13:24:22,842 - INFO - job_2.cmd = ['/home/ag239446/git/hopla/
    hopla/demo/my_ls_script.py', '-d', '/home/ag239446/git/hopla/hopla/
    test', '--verbose', '0']
2015-11-06 13:24:22,842 - INFO - job_2.exitcode = 0
2015-11-06 13:24:22,843 - INFO - Using 'hopla' version '1.0.0'.
2015-11-06 13:24:22,843 - INFO - For exitcode values:
    = 0 - no error was produced.
    > 0 - the process had an error, and exited with that code.
    < 0 - the process was killed with a signal of -1 * exitcode.
2015-11-06 13:24:22,951 - INFO - job_1.directory = /home/ag239446/git/
    hopla/hopla/test
2015-11-06 13:24:22,951 - INFO - job_1.files = ['__pycache__', 'test.py~',
    'test.pyc', 'test.py']
2015-11-06 13:24:22,952 - INFO - job_1.cmd = ['/home/ag239446/git/hopla/
    hopla/demo/my_ls_script.py', '-d', '/home/ag239446/git/hopla/hopla/
    test', '-v', '0']
2015-11-06 13:24:22,952 - INFO - job_1.exitcode = 0
2015-11-06 13:24:22,952 - INFO - job_0.directory = /home/ag239446/git/
    hopla/hopla/test
2015-11-06 13:24:22,953 - INFO - job_0.files = ['__pycache__', 'test.py~',
    'test.pyc', 'test.py']
2015-11-06 13:24:22,953 - INFO - job_0.cmd = ['/home/ag239446/git/hopla/
    hopla/demo/my_ls_script.py', '-d', '/home/ag239446/git/hopla/hopla/
    test', '-v', '0']
2015-11-06 13:24:22,953 - INFO - job_0.exitcode = 0
2015-11-06 13:24:22,955 - INFO - job_2.directory = /home/ag239446/git/
    hopla/hopla/test
2015-11-06 13:24:22,955 - INFO - job_2.files = ['__pycache__', 'test.py~',
    'test.pyc', 'test.py']
2015-11-06 13:24:22,955 - INFO - job_2.cmd = ['/home/ag239446/git/hopla/
    hopla/demo/my_ls_script.py', '-d', '/home/ag239446/git/hopla/hopla/
    test', '-v', '0']
2015-11-06 13:24:22,955 - INFO - job_2.exitcode = 0

Perspectives¶

It will be nice to generalize some concepts (ie., accept different kind of script).

Contents¶

Search¶

Search Page