The future of query-based Sync

I’ve built an app in Swift that heavily depends on query-based Sync. It would be very hard if at all possible, to rearchitect the model as fully synced realms.
Now, after I’ve consulted the MongoDB Realm Roadmap, I’ve learned that query-based Sync is kind of not recommended any more (at the moment, because it will not be integrated into MongoDB Realm public beta).

Will you support query-based Sync for Realm Cloud long enough, until it will be available in MongoDB Realm, which is planned to be brought to functionality in the second half of 2020?
And, while I do not expect any new features for query-based Sync in the meanwhile, will there be fixing for critical bugs in place?
I plan to migrate to MongoDB Realm as soon as query-based Sync will be available/stable over there.
Thank you very much for your feedback!


I’ve been looking at this as well, and what I took from reading the following:

We’ll cease new sign-ups on Realm Cloud when MongoDB Realm’s public beta launches. Current Realm Cloud users will still be able to use the platform. We ultimately expect to offer an automated or guided migration to MongoDB Realm and plan to deprecate Realm Cloud in the long-term.

…is that your app can continue to run on the existing Realm platform until you choose to swap SDKs with the new MongoDB Realm with an eventual guided migration process.

For my case, I have an app in beta and would wait until the new MongoDB Realm SDK is out of beta and properly supports query-based sync.

So my plan is to

  • stick with Realm platform
  • depend heavily on query-based sync
  • monitor MongoDB Realm development
  • once query-based sync is fully supported, migrate the app to the new SDK

I would also appreciate feedback from the Realm crew on this. Are we reading your Roadmap correctly, Realm?


This is exactly my plan, too. Can anybody from Realm comfirm that this is a viable path? Thank you!!

Hi Marcel/Eric –

We’re planning on supporting Realm Cloud for a period of time past the GA of MongoDB Realm and the goal is to give all users ample time to migrate.

Prior to the release of MongoDB Realm, we will do our best to support/address issues with Realm Cloud. However, there may be limitations inherent to the way that query-based Sync is architected that we are not able to address in this timeframe. If your application is performing well in production today then that likely means that you’re not affected, but if you are planning a significant expansion of data/users in the near future it may be worth reaching out directly so I can get a better understanding of your case and how we can work to help you be successful.

– Drew
[email protected]

1 Like