A connectionless grow-only set CRDT

Using a single message type, we show how to obtain an efficient convergence protocol for a grow-only set CRDT (Conflict-Free Replicated Data Type) although the communication channel can drop and reorder messages at will. This permits to remove the middleware layer that is usually required in CRDT protocols for providing reliable or ordered message delivery. We use the obtained grow-only set for synchronizing a compression dictionary among peers, without the need of addresses, membership protocols or connections. In this paper we describe our CRDT protocol (which is a variant of a delta-CRDT that does not have to repeatedly send the whole state), how it can be used to bootstrap other convergent data structures and report on first simulations as well as implementations for three different platforms.