crdt.md

Mutual agreement in messages order and nodes management in a multi-user chat.

Operation based CRDTs

Propagation of commutative operations rather than whole node data :

• add or remove a room.
• add, update or remove a message from a room (messages order is chosen based on sending date).
• add, remove or remove a node from a given room.

Synchronisation strategy

The nodes are connected in a fully meshed network (each node from a room has an open TCP connection to each node of the room) For now, each node propagates its operations to all other nodes :

• a new node comes in the room (the entry point node first forwards the add node operation to the other nodes).
• a message is added, updated or removed in the room.
• a node leaves the room.