diff --git a/src/kvsrv/client.go b/src/kvsrv/client.go
index 673eedb..af8da70 100644
--- a/src/kvsrv/client.go
+++ b/src/kvsrv/client.go
@@ -6,6 +6,7 @@ import (
 	"math/big"
 
 	"6.5840/labrpc"
+	"github.com/google/uuid"
 )
 
 type Clerk struct {
@@ -38,13 +39,18 @@ func MakeClerk(server *labrpc.ClientEnd) *Clerk {
 // must match the declared types of the RPC handler function's
 // arguments. and reply must be passed as a pointer.
 func (ck *Clerk) Get(key string) string {
+	id := uuid.New()
 	args := GetArgs{
-		Key: key,
+		Key:  key,
+		Uuid: id,
 	}
 	reply := GetReply{}
 	ok := false
 	for !ok {
 		ok = ck.server.Call("KVServer.Get", &args, &reply)
+		if !ok {
+			log.Println("RPC call failed: GET op")
+		}
 	}
 	// You will have to modify this function.
 	return reply.Value
@@ -60,15 +66,19 @@ func (ck *Clerk) Get(key string) string {
 // arguments. and reply must be passed as a pointer.
 func (ck *Clerk) PutAppend(key string, value string, op string) string {
 	// You will have to modify this function.
+	id := uuid.New()
 	args := PutAppendArgs{
 		Key:   key,
 		Value: value,
+		Uuid:  id,
 	}
 	reply := PutAppendReply{}
-	ok := ck.server.Call("KVServer."+op, &args, &reply)
-
-	if !ok {
-		log.Fatalf("RPC call failed: %s op", op)
+	ok := false
+	for !ok {
+		ok := ck.server.Call("KVServer."+op, &args, &reply)
+		if !ok {
+			log.Printf("RPC call failed: %s op\n", op)
+		}
 	}
 
 	return reply.Value
diff --git a/src/kvsrv/common.go b/src/kvsrv/common.go
index 8081d93..fe8cbcb 100644
--- a/src/kvsrv/common.go
+++ b/src/kvsrv/common.go
@@ -7,6 +7,7 @@ type PutAppendArgs struct {
 	// You'll have to add definitions here.
 	// Field names must start with capital letters,
 	// otherwise RPC will break.
+	Uuid string
 }
 
 type PutAppendReply struct {
@@ -16,6 +17,7 @@ type PutAppendReply struct {
 type GetArgs struct {
 	Key string
 	// You'll have to add definitions here.
+	Uuid string
 }
 
 type GetReply struct {
diff --git a/src/kvsrv/server.go b/src/kvsrv/server.go
index c726e83..b07e729 100644
--- a/src/kvsrv/server.go
+++ b/src/kvsrv/server.go
@@ -17,6 +17,7 @@ func DPrintf(format string, a ...interface{}) (n int, err error) {
 type KVServer struct {
 	mu      sync.Mutex
 	KVStore map[string]string
+	OpLog   map[string]bool
 	// Your definitions here.
 }