This will allow us to test protocol 2 in a stage environment before
removing the override to make 2 the default.
We may have seen a bug where something in celery (or an
associated library) was adding headers to a v1 message as
if it were a v2 message, which caused a bug in ddtrace; such
things may become more likely over time as code is written
with the assumption of v2 messages. Moving to v2 will avoid
those issues.
See https://github.com/edx/edx-arch-experiments/issues/800 for further details.
This should prevent the issues we've seen recently where cms modules are
imported by the running lms process, resulting in two celery instances
being created and tasks intermittently being registered to the wrong
instance (and therefore effectively lost.)
In commit ab6bf348d4/PR #25822 we tried to ensure that only one or the
other of the instances was created by adding a startup check.
Unfortunately, there's an external shared library that refers directly
to the lms celery, causing a startup failure in cms, so we had to revert
it. Rather than waiting to fix that library, this commit collapses
the two instances together so that there is only ever one.
This commit "undoes"a previous hotfix, and allows a cms course_publish
signal to trigger a block_structure update_course_in_cache task, which
is run on an lms worker queue.
Changes:
-exposes ALTERNATE_QUEUE_ENVS
-adds routing layer in celery.py
-moves prior dev_with_worker settings file to devstack_with_worker
-moves course_block api functionality into openedx/core/djangoapps/content/block_structure
