restq

Introduction to restq

---

Why restq?

We wanted to have a simple platform independent solution for managing the coordination and distribution of batched execution across our analysis platforms. restq solved our wants into a system that could:

• segregate execution based on a category or type (realm),
• manage priorities of job execution (ordered queues),
• enqueue, check-out, and expiry time based (almost FIFO) dequeuing of jobs from a realm.
• status of jobs remaining against arbitrary tag indices.
• zero configuration for the concepts talked about above.

What's in restq:

• An implementation of the execution management system described above.
• A RESTful web API that exposes complete control over the execution management system.
• A Python client that seamlessly interfaces the RESTful web API.
• Default configuration configurable through environment variables or /etc/restq.conf, ~/.restq.conf
• A command line interface accessible in the shell through the entry point 'restq'. The CLI makes it trivial to kick off a restq server. It also implements a set of commands which allow users to enqueue and dequeue commands into a realm. This makes it super trivial to deploy scheduled execution jobs across a pool of servers.

For additional tips / tricks with this restq feel free to post a question at the github restq/issues_ page.

Project hosting provided by github.com_.

|pypi_version| |build_status| |coverage|

[[e-mail]]

Install and run

Simply run the following::

> python setup.py install

or PyPi_::

> pip install restq

Coding with restq

A simple example on how ::

restq web & ipython

In [1]: from restq import Realms

In [2]: realms = Realms()

In [3]: realms.test. realms.test.add realms.test.bulk_add realms.test.bulk_flush realms.test.get_job realms.test.get_tag_status realms.test.get_tagged_jobs realms.test.name realms.test.pull realms.test.remove_job realms.test.remove_tagged_jobs realms.test.request realms.test.requester realms.test.set_default_lease_time realms.test.set_queue_lease_time realms.test.status

In [3]: realms.test.add('job 1', 0, 'do the dishes', tags=['house work'])

In [4]: realms.test.add('job 2', 0, 'cut the grass', tags=['house work'])

In [5]: realms.test.add('job 3', 1, 'fix bugs in restq', tags=['devel'])

In [6]: realms.test.add('job 4', 3, 'document restq', tags=['devel'])

In [7]: realms.test.add('job 5', 0, 'go for walk', tags=['sport'])

In [8]: realms.test.status Out[8]: {u'queues': {u'0': 4, u'1': 1, u'2': 1, u'3': 1}, u'total_jobs': 7, u'total_tags': 3}

In [9]: jobs = realms.test.pull(count=7)

In [10]: jobs Out[10]: {u'job 1': [0, u'do the dishes'], u'job 2': [0, u'cut the grass'], u'job 3': [1, u'fix bugs in restq'], u'job 4': [3, u'document restq'], u'job 5': [0, u'go for walk'], u'job 6': [0, u'go for walk with dog'], u'job 7': [2, u'go for bike ride']}

In [11]: realms.test.get_tag_status('house work') Out[11]: {u'count': 2}

In [12]: realms.test.get_tagged_jobs('devel') Out[12]: {u'job 3': {u'data': u'fix bugs in restq', u'queues': [[1, 82.17003393173218]], u'tags': [u'devel']}, u'job 4': {u'data': u'document restq', u'queues': [[3, 82.16989994049072]], u'tags': [u'devel']}}

Using restq's CLI

Adding arguments into the default realm

Add the argument "ls -lah" into the default realm. ::

restq add "ls -lah"

If we want to refer to a group of commands we can tag a command (even if it already exists).

Tag the argument "ls -lah" with a label of 'work'. ::

restq add --tags=work "ls -lah"

Add another argument to the realm, but this time we'll tag it with work and fun. ::

restq add --tags=work,fun pwd

Checkout the status of the realm. ::

restq status Status of realm default: Contains 2 tags with 2 jobs Defined queues: 0

Time to add pwd to another queue. ::

restq add --queue=1 pwd

restq status Status of realm default: Contains 2 tags with 2 jobs Defined queues: 1, 0

Pulling (or doing a checkout) of arguments for execution

Continuation from the previous example.

Pull and execute a maximum of two arguments from the default realm. After the default time out, these arguments will be available for checkout once again. ::

while read i; do eval "$i"; done < <(restq pull --count=2) drwxr-xr-x 9 mick mick 4.0K Jul 18 08:01 . drwxrwxr-x 9 mick mick 4.0K Jul 14 03:07 .. drwxrwxr-x 3 mick mick 4.0K Jul 12 00:04 docs -rw-rw-r-- 1 mick mick 72 Jul 12 00:04 MANIFEST.in -rw-rw-r-- 1 mick mick 3.7K Jul 12 00:04 README.rst drwxrwxr-x 2 mick mick 4.0K Jul 17 23:13 restq -rw-rw-r-- 1 mick mick 2.1K Jul 17 19:57 setup.py drwxrwxr-x 2 mick mick 4.0K Jul 12 00:04 tests -rw-rw-r-- 1 mick mick 321 Jul 12 00:04 .travis.yml /home/mick/work/restq

The argument pwd was placed into two queues. The next pull will see pwd being dequeued from queue 1. ::

restq pull pwd

Lets check the status of the pwd argument since checkout. This shows what queues a specific argument is in, what tags it has, and how long it has been since it was checked out (pulled). ::

restq status arg pwd Status of argument pwd: Tagged with: work queue id | (s) since dequeue 1 | 35.22 0 | 454.49

Time to remove pwd from our realm... We're done with this argument and we no longer require it for execution. You will notice that the fun tag no longer exists in the realm as it was only attached to pwd. ::

restq remove arg pwd

The default lease time for a dequeue of an argument is 600s. After this expiry time, 'ls -lah' will once again be available for dequeue. ::

restq pull ls -lah

How to distribute a shell script for execution

Add 'work.sh' script into the default realm. ::

restq add --file=work.sh "chmod +x work.sh; ./work.sh"

Now when this job is dequeued using the restq cli, the path './work.sh' will be written to using the data read from the original 'work.sh' and the arguments will be written out to stdout. ::

eval "restq pull"

The following is an example of a script that could be deployed across multiple machines to continuously pull and execute jobs that have been added into the default realm. ::

while [ 1 ]; do while read i; do eval "$i"; done < <(restq pull); sleep 1; done

Issues

Source code for restq is hosted on GitHub <https://github.com/provoke-vagueness/restq>. Please file bug reports <https://github.com/provoke-vagueness/restq/issues> with GitHub's issues system.

Change log

version 0.1.2 (26/08/2013)

• bulk add and removal

version 0.1.0 (18/07/2013)

• implemented cli controls.
• realms now using yaml -> breaks compatibility with previous version.

version 0.0.4 (09/06/2013)

• config and cli shell implementation

version 0.0.3 (06/06/2013)

• bulk post & stable error handling

version 0.0.1 (10/04/2013)

• pre life

Contributions

Contributions to restq:

• [[e-mail]]

.. _github.com: https://github.com/provoke-vagueness/restq .. _PyPi: http://pypi.python.org/pypi/restq .. _restq/issues: https://github.com/provoke-vagueness/restq/issues .. |coverage| image:: https://coveralls.io/repos/provoke-vagueness/restq/badge.png?branch=master :target: https://coveralls.io/r/provoke-vagueness/restq?branch=master :alt: Latest PyPI version .. |pypi_version| image:: https://pypip.in/v/restq/badge.png :target: https://crate.io/packages/restq/ :alt: Latest PyPI version .. |build_status| image:: https://secure.travis-ci.org/provoke-vagueness/restq.png?branch=master :target: http://travis-ci.org/#!/provoke-vagueness/restq