pystalk 0.8.0

pystalk is an extremely simple Python client for beanstalkd.

This project was initially created for beancmd. You may also be interested in that tool!

Note that none of the objects in this package are inherently synchronized (thread-safe), and if you are going to use them from multiple threads, you should always protect them with a mutex. Clients are also not fork-safe, and should be initialized after any forking.

Requirements / Installing

This software works with Python 3.6+. It should work PyPy3 but has not been tested extensively.

It does not support any asynchronous event loops and has not been tested with gevent. It's designed for simple, synchronous use.

You should be able to install it from PyPI with pip install pystalk.

Example Usage

Creating Jobs

#!/usr/bin/python

import json

from pystalk import BeanstalkClient

client = BeanstalkClient('10.0.0.1', 11300)
client.put_job(json.dumps({"foo": "bar"}), delay=30)

This will create a job with a 30-second delay on it. Note that the data for a job must be UTF-8 encodable.

Creating Jobs in Specific Tubes

Beanstalk has a notion of tubes (which is to say, named queues). There are several ways to put a job into a specific tube using pystalk:

#!/usr/bin/python

from pystalk import BeanstalkClient

client = BeanstalkClient('10.0.0.1', 11300)

# method 1, matches the upstream protocol
client.use("some_tube")
client.put_job("some message")

# method 2, using an external guard object like you would in C++ or Rust
with client.using("some_tube") as inserter:
    inserter.put_job("some message")


# method 3
client.put_job_into("some_tube", "some message")

Consuming All Available Jobs

The following script will walk through all currently-READY jobs and then exit:

#!/usr/bin/python

from pystalk import BeanstalkClient

client = BeanstalkClient('10.0.0.1', 11300)
client.watch('some_tube')
for job in client.reserve_iter():
    try:
        execute_job(job)
    except Exception:
        client.release_job(job.job_id)
        raise
    client.delete_job(job.job_id)

Note that, even though we require that job data be UTF-8 encodeable in the put_job method, we do not decode for you -- the job data that comes out is a byte-string in Python 3.5. You should call .decode("utf-8") on it if you want to get the input data back out. If you would like that behavior, pass auto_decode=True to the BeanstalkClient constructor; note that this might make it difficult for you to consume data injected by other systems which don't assume UTF-8.

Producing into Multiple Job Servers

This library includes the ProductionPool class, which will insert jobs into beanstalk servers, rotating between them when an error occurs. Example usage:

from pystalk import BeanstalkClient, ProductionPool

pool = ProductionPool.from_uris(
    ['beanstalkd://10.0.0.1:10300', 'beanstalkd://10.0.0.2:10300'],
    socket_timeout=10
)
pool.put_job_into('some tube', 'some job')

The Pool only supports the put_job and put_job_into methods and makes no fairness guarantees; you should not use it for consumption.

Consuming From Multiple Job Servers

The following will reserve jobs from a group of Beanstalk servers, fairly rotating between them.

#!/usr/bin/python

from myapp import execute_job
from pystalk import BeanstalkClient, BeanstalkTimedOutError

hosts = ('10.0.0.1', '10.0.0.2')
clients = dict((h, BeanstalkClient(h, 11300)) for h in hosts)

i = 0
while True:
    i += 1
    client = clients[hosts[i % len(hosts)]]
    try:
        job = client.reserve_job(1)
    except BeanstalkError as e:
        if e.message == 'TIMED_OUT':
            continue
        else:
            raise
    execute_job(job)
    client.delete_job(job.job_id)

Development

Pretty straightforward. Develop in branches, send PRs, land on master. All tests must pass before landing.

Releasing a new version

1. Land all requisite changes
2. Bump the version in pystalk/__init__.py to the stable version (e.g., 0.9.0)
3. Update CHANGES.rst with the changes and the new version number
4. Commit and push up to Github
5. Draft a new GitHub Release, targeting a new tag matching the version (e.g., 0.9.0)
6. Publishing the release triggers the release GitHub Actions workflow, which builds the sdist/wheel and publishes them to PyPI automatically