On 2017-06-20 21:00, calendarserver-users-request@lists.macosforge.org wrote:

Is it possible for me to change calendarServer to use mongoDB instead of XMLdirectoryService? Any disadvantages?

Yes. The backend directory is relatively plugable. So, apart from the general potential consistency issues with mongoDB, it should be possible to write a DirectoryService backed by any database.

If so, could you please point me to relevant source to start?

You need to implement a DirectoryService and DirectoryRecord in txdav/who. Be aware of caching, augmenting and the DPS service which can complicate stuff. txdav/who/util.py contains the code to put everything together and create the final directory used. /Peter