The official website was not found. . . Tragedy. . . Asking for popular science.
There are many things, but the main ones are the following:
* write lock for documentlevel (currently database level). This will greatly improve the concurrency of mongo.
* Replaceable Storage Engines-Users will be able to choose storage engines that support compression, encryption or other types according to their needs.
* MMS automation-Automatically Deploy, Upgrade, Manage Mongo Clusters