edX.org is starting to plan our Mongo 3.6 to Mongo 4.0 upgrade for next quarter. While there are a handful of breaking changes with the upgrade which you can read about here, nothing stands out like it will impact application code for forums or modulestore.
The most notable change with this upgrade is actually the license change made to prevent SaaS providers like AWS and other from offering their DB as a service without paying any fees. This means if you are using a mongo SaaS provider today they will likely never upgrade beyond the 3.6 apis. So I wanted to highlight that now and see if there are any concerns and/or other conversations we should be having around this topic.
Is anyone running on MongoDB 4.0 or greater right now? Any tips to share?
Is anyone running on a SaaS provider right now that only offers 3.6 compatibility?
MongoDB Atlas should also be fine because it is the official MongoDB cloud offering. As is running the community edition yourself via any cloud provider.
The request here is that people check to ensure that however they host mongo they can plan for moving to 4.0 (and this more than any other upgrade it is not guaranteed to be upgradable by all providers).