From 5b5fc705bead549fdbad975c303a0c6cda7c4671 Mon Sep 17 00:00:00 2001
From: Brandon Philips <brandon@ifup.co>
Date: Thu, 23 Jan 2014 12:42:06 -0800
Subject: [PATCH] docs(server): add a comment explaining the NOPCommand

---
 server.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/server.go b/server.go
index b3529bd979..9f32740bbc 100644
--- a/server.go
+++ b/server.go
@@ -763,6 +763,10 @@ func (s *server) leaderLoop() {
 		peer.startHeartbeat()
 	}
 
+	// Commit a NOP after the server becomes leader. From the Raft paper:
+	// "Upon election: send initial empty AppendEntries RPCs (heartbeat) to
+	// each server; repeat during idle periods to prevent election timeouts
+	// (§5.2)". The heartbeats started above do the "idle" period work.
 	go s.Do(NOPCommand{})
 
 	// Begin to collect response from followers