Pyleus

Pyleus is a Python 2.6+ framework for developing and launching Apache Storm_ topologies.

Please visit our documentation_.

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About

Pyleus is a framework for building Apache Storm topologies in idiomatic Python.

With Pyleus you can:

• define a topology with a simple YAML file

• have dependency management with a requirements.txt file

• run faster thanks to Pyleus’ MessagePack_ based serializer

• pass options to your components directly from the YAML file

• use the Kafka spout built into Storm with only a YAML change

Install

From PyPI:

.. code-block:: shell

$ pip install pyleus

Note:

You do NOT need to install pyleus on your Storm cluster. That’s cool, isn't it?

However, if you are going to use system_site_packages: true in your config file, you should be aware that the environment of your Storm nodes needs to match the one on the machine used for building the topology. This means you actually have to install pyleus on your Storm cluster in this case.

Try it out!

.. code-block:: shell

$ git clone https://github.com/Yelp/pyleus.git $ pyleus build pyleus/examples/exclamation_topology/pyleus_topology.yaml $ pyleus local exclamation_topology.jar

Or, submit to a Storm cluster with:

.. code-block:: shell

$ pyleus submit -n NIMBUS_HOST exclamation_topology.jar

The examples_ directory contains several annotated Pyleus topologies that try to cover as many Pyleus features as possible.

Pyleus command line interface

• Build a topology:

  .. code-block:: shell

  $ pyleus build /path/to/pyleus_topology.yaml

• Run a topology locally:

  .. code-block:: shell

  $ pyleus local /path/to/topology.jar

• Submit a topology to a Storm cluster:

  .. code-block:: shell

  $ pyleus submit [-n NIMBUS_HOST] /path/to/topology.jar

• List all topologies running on a Storm cluster:

  .. code-block:: shell

  $ pyleus list [-n NIMBUS_HOST]

• Kill a topology running on a Storm cluster:

  .. code-block:: shell

  $ pyleus kill [-n NIMBUS_HOST] TOPOLOGY_NAME

Try pyleus -h for a list of all the available commands or pyleus CMD -h for any command-specific help.

Write your first topology

Please refer to the documentation_ for a more detailed tutorial.

Organize your files ^^^^^^^^^^^^^^^^^^^

This is an example of the directory tree of a simple topology:

.. code-block:: none

my_first_topology/ |-- my_first_topology/ | |-- init.py | |-- dummy_bolt.py | |-- dummy_spout.py |-- pyleus_topology.yaml |-- requirements.txt

Define the topology layout ^^^^^^^^^^^^^^^^^^^^^^^^^^

A simple pyleus_topology.yaml should look like the following:

.. code-block:: yaml

name: my_first_topology

topology:

   - spout:
       name: my-first-spout
       module: my_first_topology.dummy_spout

   - bolt:
       name: my-first-bolt
       module: my_first_topology.dummy_bolt
       groupings:
           - shuffle_grouping: my-first-spout

This defines a topology where a single bolt subscribes to the output stream of a single spout. As simple as it is.

Write your first spout ^^^^^^^^^^^^^^^^^^^^^^

This is the code implementing dummy_spout.py:

.. code-block:: python

from pyleus.storm import Spout

class DummySpout(Spout):

   OUTPUT_FIELDS = ['sentence', 'name']

   def next_tuple(self):
       self.emit(("This is a sentence.", "spout",))

if name == 'main': DummySpout().run()

Write your first bolt ^^^^^^^^^^^^^^^^^^^^^

Let's now look at dummy_bolt.py:

.. code-block:: python

from pyleus.storm import SimpleBolt

class DummyBolt(SimpleBolt):

   OUTPUT_FIELDS = ['sentence']

   def process_tuple(self, tup):
       sentence, name = tup.values
       new_sentence = "{0} says, \"{1}\"".format(name, sentence)
       self.emit((new_sentence,), anchors=[tup])

if name == 'main': DummyBolt().run()

Run your topology ^^^^^^^^^^^^^^^^^

Run the topology on your local machine for debugging:

.. code-block:: shell

pyleus build my_first_topology/pyleus_topology.yaml pyleus local --debug my_first_topology.jar

When you are done, hit C-C.

Configuration File ^^^^^^^^^^^^^^^^^^

You can set default values for many configuration options by placing a .pyleus.conf file in your home directory:

.. code-block:: none

[storm] nimbus_host: 10.11.12.13 jvm_opts: -Djava.io.tmpdir=/home/myuser/tmp

[build] pypi_index_url: http://pypi.ninjacorp.com/simple/

Reference

• Apache Storm Documentation_

License

Pyleus is licensed under the Apache License, Version 2.0: http://www.apache.org/licenses/LICENSE-2.0

.. _Apache Storm: https://storm.apache.org/ .. _Apache Storm Documentation: https://storm.apache.org/documentation/Home.html .. _MessagePack: http://msgpack.org/ .. _documentation: http://pyleus.org/ .. _examples: https://github.com/Yelp/pyleus/tree/master/examples