Storage synchronization

Question

Database

You have to write an application that works most of the time with local storage and periodically synchronizes with the central one (for example, the cloud).
One user can have several applications (applications on the desktop, tablet, smartphone).
Those. you need to do something like Evernote.

Tell me what to read from the theory?

The storage type is sql, but it could be something else, such as Indexed Database .
It is assumed that the repository will contain a directed graph (cyclic dependencies are possible).
As I understand it, there are two approaches:
1. Tracking changes and rolling them between repositories. (like mercurial)
2. Merge of two states. (like svn'a)
Please do not send to version control systems - you want something simpler, so there will most likely be the second option.
Maybe an overview of who saw different approaches in synchronization?

Answer 1

Why are you afraid of version control systems? I think git is just perfect for your situation.
The problem is that it will depend heavily on the specifics of the data. No utility can decide how to resolve conflicts for you, so this will be the main problem

Answer 2

The version control system is too heavy.
I need something small, with fully automatic conflict resolution.
You need to write something like evernote, I won’t integrate git for this)

Answer 3

The details of the task are not clear, but offhand snapshot + rsync if it's linux.