raft cluster

wip: raft does not care about migrating

wip: optimize code

wip: raft election

wip

wip: fix raft leader missing log entries

wip

fix a dead lock

batch set slot route

wip: raft persist

wip

refactor cluster suite

remove relay

rename relay2

refactor: allow customizing client factory

test raft

refactor re-balance

avoid errors caused by inconsistent status on follower nodes during raft commits

test raft election

lib/utils/rand_string.go

@@ -5,14 +5,14 @@ import (
 	"time"
 )
 
+var r = rand.New(rand.NewSource(time.Now().UnixNano()))
 var letters = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")
 
 // RandString create a random string no longer than n
 func RandString(n int) string {
-	nR := rand.New(rand.NewSource(time.Now().UnixNano()))
 	b := make([]rune, n)
 	for i := range b {
-		b[i] = letters[nR.Intn(len(letters))]
+		b[i] = letters[r.Intn(len(letters))]
 	}
 	return string(b)
 }
@@ -22,7 +22,19 @@ var hexLetters = []rune("0123456789abcdef")
 func RandHexString(n int) string {
 	b := make([]rune, n)
 	for i := range b {
-		b[i] = hexLetters[rand.Intn(len(hexLetters))]
+		b[i] = hexLetters[r.Intn(len(hexLetters))]
 	}
 	return string(b)
 }
+
+// RandIndex returns random indexes to random pick elements from slice
+func RandIndex(size int) []int {
+	result := make([]int, size)
+	for i := range result {
+		result[i] = i
+	}
+	rand.Shuffle(size, func(i, j int) {
+		result[i], result[j] = result[j], result[i]
+	})
+	return result
+}