lease: randomize TTL on recovery

Address etcd-io#8096. Signed-off-by: Gyu-Ho Lee <gyuhox@gmail.com>
gyuho · Jun 14, 2017 · 3d1cfa5 · 3d1cfa5
1 parent e6d2667
commit 3d1cfa5
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/lease/lessor.go b/lease/lessor.go
@@ -18,6 +18,7 @@ import (
 	"encoding/binary"
 	"errors"
 	"math"
+	"math/rand"
 	"sort"
 	"sync"
 	"sync/atomic"
@@ -475,6 +476,9 @@ func (le *lessor) initAndRecover() {
 		if lpb.TTL < le.minLeaseTTL {
 			lpb.TTL = le.minLeaseTTL
 		}
+		// randomize +/-10%, so that recovered leases with same TTL
+		// do not expire all at the same time
+		lpb.TTL += rand.Int63n(lpb.TTL/10) * int64((-(i & 1))|1)
 		le.leaseMap[ID] = &Lease{
 			ID:  ID,
 			ttl: lpb.TTL,