Integration package for zc.async allowing asynchronous operations in Plone 4 and 5.

• https://github.com/plone/plone.app.async

You will typically run plone.app.async in a ZEO environment, where you will have one or more worker instances carrying out jobs queued by your main zope instances.

For the sake of simplicity it is assumed that you have one instance that can queue new jobs, and one worker instance that consumes them, both operating on a single database. In this case your buildout configuration will look similar to the following:

[zeo]
recipe = plone.recipe.zope2zeoserver
file-storage = ${buildout:directory}/var/filestorage/Data.fs

[instance]
recipe = plone.recipe.zope2instance
eggs = Plone plone.app.async
zcml =
zcml-additional =
    <include package="plone.app.async" file="single_db_instance.zcml" />
environment-vars =
    ZC_ASYNC_UUID ${buildout:directory}/var/instance-uuid.txt

[worker]
recipe = plone.recipe.zope2instance
eggs = ${instance:eggs}
zcml = ${instance:zcml}
zcml-additional =
    <include package="plone.app.async" file="single_db_worker.zcml" />
environment-vars =
    ZC_ASYNC_UUID ${buildout:directory}/var/worker-uuid.txt

There are two important stanzas here:

• Each instance has to set the ZC_ASYNC_UUID environment variable in order to integrate properly with zc.async.
• Each instance loads the single_db_instance.zcml configuration. The worker instance loads the single_db_worker.zcml configuration in order to setup the queue and configure itself as a dispatcher.

For more details please look at the example buildout configurations included in the package.

Code from Enfold's plone.async.core package has been used for setting up the queues.

• zc.async on PyPI
• plone.async.core Subversion repository