diff --git a/control/control.go b/control/control.go
index 60b339ef..2ef0a398 100644
--- a/control/control.go
+++ b/control/control.go
@@ -269,7 +269,7 @@ func step2(cfg Config) error {
 			}()
 			for i := range conns {
 				wg.Add(1)
-				go doPutZk(conns[i], requests)
+				go doPutZk(conns[i], requests, cfg.Step2.SameKey)
 			}
 
 		case "consul":
diff --git a/control/report.go b/control/report.go
index 4782dc11..0b66ddf6 100644
--- a/control/report.go
+++ b/control/report.go
@@ -80,10 +80,7 @@ func wrapReport(f func()) <-chan struct{} {
 func (r *report) finalize() {
 	log.Printf("finalize has started")
 	st := time.Now()
-	i := 0
 	for res := range r.results {
-		i++
-		fmt.Println("finalize from results:", i, res)
 		if res.errStr != "" {
 			r.errorDist[res.errStr]++
 		} else {
diff --git a/control/util.go b/control/util.go
index e3f6dde4..c21567fc 100644
--- a/control/util.go
+++ b/control/util.go
@@ -260,24 +260,29 @@ func getTotalKeysEtcdv3(endpoints []string) map[string]int64 {
 	return rs
 }
 
-func doPutZk(conn *zk.Conn, requests <-chan request) {
+func doPutZk(conn *zk.Conn, requests <-chan request, sameKey bool) {
 	defer wg.Done()
 
-	i := 0
+	var idx int32
 	for req := range requests {
-		i++
 		op := req.zkOp
 		st := time.Now()
 
-		_, err := conn.Create(op.key, op.value, zkCreateFlags, zkCreateAcl)
+		var err error
+		if !sameKey || idx == 0 {
+			_, err = conn.Create(op.key, op.value, zkCreateFlags, zkCreateAcl)
+		} else {
+			_, err = conn.Set(op.key, op.value, idx)
+		}
 
 		var errStr string
 		if err != nil {
 			errStr = err.Error()
 		}
-		fmt.Println("sent to results:", i, errStr, op.key, op.value)
 		results <- result{errStr: errStr, duration: time.Since(st), happened: time.Now()}
 		bar.Increment()
+
+		idx++
 	}
 }