Merge pull request #369 from stevvooe/heartbeat-should-be-duration

swarm: clarify meaning of time related fields

types/swarm/swarm.go

@@ -54,13 +54,27 @@ type RaftConfig struct {
 	SnapshotInterval           uint64 `json:",omitempty"`
 	KeepOldSnapshots           uint64 `json:",omitempty"`
 	LogEntriesForSlowFollowers uint64 `json:",omitempty"`
-	HeartbeatTick              uint32 `json:",omitempty"`
-	ElectionTick               uint32 `json:",omitempty"`
+
+	// ElectionTick is the number of ticks that a follower will wait for a message
+	// from the leader before becoming a candidate and starting an election.
+	// ElectionTick must be greater than HeartbeatTick.
+	//
+	// A tick currently defaults to one second, so these translate directly to
+	// seconds currently, but this is NOT guaranteed.
+	ElectionTick int
+
+	// HeartbeatTick is the number of ticks between heartbeats. Every
+	// HeartbeatTick ticks, the leader will send a heartbeat to the
+	// followers.
+	//
+	// A tick currently defaults to one second, so these translate directly to
+	// seconds currently, but this is NOT guaranteed.
+	HeartbeatTick int
 }
 
 // DispatcherConfig represents dispatcher configuration.
 type DispatcherConfig struct {
-	HeartbeatPeriod uint64 `json:",omitempty"`
+	HeartbeatPeriod time.Duration `json:",omitempty"`
 }
 
 // CAConfig represents CA configuration.