82ec7159a8
We have found that for many courses on edx.org, the "current version" of the course that's stored in MongoDB doesn't match what's stored in MySQL. Although this doesn't directly cause any problems as the "current version" (course index) is not normally read from MongoDB, it's not supposed to happen - and it can cause problems if some other extra-platform components (like a pruner script) read the course indexes out of MongoDB. We still aren't sure what can cause MongoDB and MySQL to get out of sync in the first place; this won't necessarily fix that issue. What this does fix is a bug that seems to be: once they get out of sync, they stay out of sync and mongo will stop receiving writes. The Mongo code in most cases will only write a new record if the "current" record's last_update matches the last_update value before the change was made. e.g. last_update is "10am", user makes a change, Mongo gets updated only if the current row's last_update is still "10am". Otherwise it's considered a "collision" and silently ignored. Once Mongo and MySQL somehow become out of sync, they may stay out of sync because any new writes will have a last_update value read from MySQL, which is newer than the value in MongoDB, so the MongoDB writes will all be rejected as "collisions". This should fix the issue by making mongo writes always match the MySQL writes, instead of letting the Mongo code "decide on its own" when to write course index updates or not.
This is the core repository of the Open edX software. It includes the LMS
(student-facing, delivering courseware), and Studio (course authoring)
components.
Installation
------------
Installing and running an Open edX instance is not simple. We strongly
recommend that you use a service provider to run the software for you. They
have free trials that make it easy to get started:
https://openedx.org/get-started/
If you will be modifying edx-platform code, the `Open edX Developer Stack`_ (Devstack) is
a Docker-based development environment.
If you want to run your own Open edX server and have the technical skills to do
so, `Open edX Installation Options`_ explains your options.
.. _Open edX Developer Stack: https://github.com/edx/devstack
.. _Open edX Installation Options: https://openedx.atlassian.net/wiki/spaces/OpenOPS/pages/60227779/Open+edX+Installation+Options
License
-------
The code in this repository is licensed under version 3 of the AGPL
unless otherwise noted. Please see the `LICENSE`_ file for details.
.. _LICENSE: https://github.com/edx/edx-platform/blob/master/LICENSE
More about Open edX
-------------------
See the `Open edX site`_ to learn more about the Open edX world. You can find
information about hosting, extending, and contributing to Open edX software. In
addition, the Open edX site provides product announcements, the Open edX blog,
and other rich community resources.
.. _Open edX site: https://openedx.org
Documentation
-------------
Documentation can be found at https://docs.edx.org.
Getting Help
------------
If you're having trouble, we have discussion forums at
https://discuss.openedx.org where you can connect with others in the community.
Our real-time conversations are on Slack. You can request a `Slack
invitation`_, then join our `community Slack team`_.
For more information about these options, see the `Getting Help`_ page.
.. _Slack invitation: https://openedx.org/slack
.. _community Slack team: http://openedx.slack.com/
.. _Getting Help: https://openedx.org/getting-help
Issue Tracker
-------------
We use JIRA for our issue tracker, not GitHub issues. You can search
`previously reported issues`_. If you need to report a problem,
please make a free account on our JIRA and `create a new issue`_.
.. _previously reported issues: https://openedx.atlassian.net/projects/CRI/issues
.. _create a new issue: https://openedx.atlassian.net/secure/CreateIssue.jspa?issuetype=1&pid=11900
How to Contribute
-----------------
Contributions are welcome! The first step is to submit a signed
`individual contributor agreement`_. See our `CONTRIBUTING`_ file for more
information – it also contains guidelines for how to maintain high code
quality, which will make your contribution more likely to be accepted.
Reporting Security Issues
-------------------------
Please do not report security issues in public. Please email
security@edx.org.
.. _individual contributor agreement: https://openedx.org/cla
.. _CONTRIBUTING: https://github.com/edx/edx-platform/blob/master/CONTRIBUTING.rst