fh-django-gae-tasks 0.1.1

Django GAE tasks improves upon App Engine's Deferred library and is forked from FreshPlanet's project.

This is forked from FreshPlanet’s improved App Engine Deferred module. and has the added functionality of having a Django View along with the webapp2 handler so that it can be used in either project type.

The AppEngine Python SDK has a great module when it comes to easily run some code “later”: the deferred library (if you are unfamiliar with this library, please have a look at its documentation first).

However the library has a few drawbacks that we solve here:

• No asynchronous method (issue 9530)

• The internal request handler inherits from webapp instead of webapp2 which can be an issue when using some webapp2 features (like webapp2.get_request)

• It uses pickle instead of leveraging cPickle available with the Python 2.7 runtime.

• The Route it uses is internal and will skip your middlewares unless you define them in a special appengine_config.py module.

• Task could fail to properly execute when hitting a fresh instance which did not had all code loaded

• Logging is a bit verbose: it uses the INFO level to show task headers that are redundant with what we can see by default in the AppEngine logs

We also added a couple of features to it:

• Explicit URLs for tasks: instead of just seeing /_ah/queue/deferred in your logs you will see something like /_cb/deferred/app.module.name/funcName

• Possibility to spread tasks over several queues in case of high throughput

• Improved logging in case of error

• Possibility to tie it to a background module to optimize serving requests

And some helpers: - isFromTaskQueue(): Check if we are currently running from a task queue - getRetryCount(): Returns the current number of times the current task is being retried - logAsRetried(): Depending on # of times the task is being retried, we will increase the logging level.

Our module still makes use of the deferred exceptions types `SingularTaskFailure` and `PermanentTaskFailure` to be compatible with existing code.

Installation

1. pip install fh-django-gae-tasks

2. Load the app in your Django project’s settings.py

INSTALLED_APPS = (
    'gae_tasks'
)

3. Load the URL for the app

urlpatterns = [
    url(r'^', include('gae_tasks.urls')),
]

4. Optionally, better integrate with your application by updating the tasks settings:

GAE_TASKS_DISABLE: False
GAE_TASKS_WARMUP_MODULE: None
GAE_TASKS_DEFAULT_QUEUES: ['default']
GAE_TASKS_BACKGROUND_MODULE: None

(See the tasks module for more details)