0. What is Leto mean?
In Greek mythology, Leto (/ˈliːtoʊ/) is a daughter of the Titans Coeus and Phoebe, the sister of Asteria.
1. What is Leto?
Raft is a consensus algorithm that is designed to be easy to understand. It’s equivalent to Paxos in fault-tolerance and performance. The difference is that it’s decomposed into relatively independent subproblems, and it cleanly addresses all major pieces needed for practical systems. We hope Raft will make consensus available to a wider audience, and that this wider audience will be able to develop a variety of higher quality consensus-based systems than are available today.
2. Why do this?
You can have better comprehension about how
raft protocal works if you use it. This helps me a lot.
3. Run sample
3.1 show helps
bin/leto -h Usage of bin/leto: -id string node id -join string join to already exist cluster -listen string server listen address (default ":5379") -raftbind string raft bus transport bind address (default ":15379") -raftdir string raft data directory (default "./")
3.2 Start first node
bin/leto -id id1 -raftdir ./id1
the first node will be listen user request and node join request in port
5379, and use port
15379 for raft transport.
3.3 Start second node
bin/leto -id id2 -raftdir ./id2 -listen ":6379" -raftbind ":16379" -join "127.0.0.1:5379"
3.4 Start third node
bin/leto -id id3 -raftdir ./id3 -listen ":7379" -raftbind ":17379" -join "127.0.0.1:5379"
Requst first node
redis-cli -p 5379 127.0.0.1:5379> set a b OK 127.0.0.1:5379> get a b 127.0.0.1:5379>
Write to second node, data has been replicated to this node. And it will return
not leader error if write to it.
redis-cli -p 6379 127.0.0.1:6379> get a b 127.0.0.1:6379> set a b (error) not leader 127.0.0.1:6379>
shutdown the first node, the second node voted to be leader.
redis-cli -p 6379 127.0.0.1:6379> get a b 127.0.0.1:6379> set a b OK 127.0.0.1:6379>
4. Support commands
- JOIN (communicate with peer when start node)
- LEAVE (remove dead node from raft group)
- SNAPSHOT (trigger snapshot mannually)