How to organize a decentralized network service?

Question

Computer networks

There is a desire to implement a certain service based on an Android application. The service must be decentralized, that is, information in the form of one common database must be transferred from client to client, and not downloaded from the server. How can this be organized? How can devices find each other on the Internet? It is interesting from an architectural point of view.

Answer 1

It is advisable to create a hierarchy, but there must be a server or resource that stores a value vertically, horizontally, the ip of the client, as well as the number of each update (each update +1 to the existing number - 0, 1, 2, etc.). How the clients should be placed - the main one is -0, there is a lower order - 1, another - 2. Each order forms a layer. This creates a matrix.
Something like this. The server is needed only for connection, and the transfer will be between clients directly.