I came across a problem statement which requires,offline syncing capabilities for application. In this scenario the user would fill the data in provided sheets and may and may not have network available. Whenever he comes in network the client should sync the data. There can be two types of server one is satelite server which would be temperory storage or staging for the data filled in sheet, this might be in internet or intranet so as first step the client would push the data to this server and then there would be cloud server in Azure or AWS which would be the ultimate source of truth and the data finally would be synced here.

The application is going to be in MEAN Stack and since NoSql doesn't follow the ACID properties how would I insure the data integrity in NoSql world. In other word how do I insure that every time the sync happens it happens to the certain checkpoint and if it doesn't then it rollsback? The data volume is going to be huge since it is an enterprise application.

Also couch db or pouch db or any other db is not an option. It is either going to be mongo or Azure's DocumentDB.