Distributed chat application written in Go. Proof of concept rather than fully finished and polished product.
Depends on gocui for UI.
- A node needs to start a new network - when it does so, it's automatically elected as its leader
- When a new node connects, it becomes the new successor to the known node (which it used to join the network)
- Virtual ring used for leader election is separate from virtual star used for chatting
- When a node's successor is lost, it tries to connect to the old successor's successor first (if that fails, it sends
closeringrequest through previous node) - When a leader is lost, each node waits a random amount of time before starting a new election, except for the old leader's predecessor, which starts election immediately once it detects that the ring topology has been fixed
- Node IP is taken from the first non-loopback interface that has an IP address
- Node IDs are based on said IPs (won't work through NAT etc.)
- Current protocol doesn't allow sending newline character (
\n) and semicolons must be handled with care
- Connected nodes elect a leader node between themselves (when an existing leader is lost) that works as a chat server using Chang-Roberts algorithm
- The entire system tries to keeps itself in a consistent state (each node has a successor, leader is elected)
- The system is able to reliably handle a single node failure at a time
- Chat functionality itself is rather basic
- Synchronization is an incredible mess that works by the sheer force of will
- Not the cleanest Go codebase there is (certainly not idiomatic)