etcd-team/etcd — pull request #11 by xiangli-cmu (2014-07-24 21:33:44+00:00)
Title: Raft log

Prepare for persistency.
We need to persist:
1. New log entries
2. term change
3. vote change
4. configuration change (via persist commitIndex)
before send out any reply message after Node.Step.

The workflow will be
```go
n.Step(m)
wal.SaveEnts(n.UnstableEnts())
wal.SaveState(n.UnstableState())
peerHub.Send(n.Msgs())
```
@bmizerany @unihorn