diff --git a/src/hiredis.c b/src/hiredis.c
index e2a483f..dd21d60 100644
--- a/src/hiredis.c
+++ b/src/hiredis.c
@@ -1028,6 +1028,20 @@ static int redisNextInBandReplyFromReader(redisContext *c, void **reply) {
     return REDIS_OK;
 }
 
+int redisFlush(redisContext *c) {
+    int wdone = 0;
+    void *aux = NULL;
+    /* Try to read pending replies */
+    if (redisNextInBandReplyFromReader(c,&aux) == REDIS_ERR)
+        return REDIS_ERR;
+    /* Write until done */
+    do {
+        if (redisBufferWrite(c,&wdone) == REDIS_ERR)
+            return REDIS_ERR;
+    } while (!wdone);
+    return REDIS_OK;
+}
+
 int redisGetReply(redisContext *c, void **reply) {
     int wdone = 0;
     void *aux = NULL;
diff --git a/src/hiredis.h b/src/hiredis.h
index 332db5b..057fafd 100644
--- a/src/hiredis.h
+++ b/src/hiredis.h
@@ -315,6 +315,7 @@ redisFD redisFreeKeepFd(redisContext *c);
 int redisBufferRead(redisContext *c);
 int redisBufferWrite(redisContext *c, int *done);
 
+int redisFlush(redisContext *c);
 /* In a blocking context, this function first checks if there are unconsumed
  * replies to return and returns one if so. Otherwise, it flushes the output
  * buffer to the socket and reads until it has a reply. In a non-blocking
diff --git a/src/redis-migrate.c b/src/redis-migrate.c
index 9da53c8..572ccd0 100644
--- a/src/redis-migrate.c
+++ b/src/redis-migrate.c
@@ -16,6 +16,7 @@ migrateObj *createMigrateObject(robj *host, int port, int begin_slot, int end_sl
     m->begin_slot = begin_slot;
     m->end_slot = end_slot;
     m->repl_stat = REPL_STATE_NONE;
+    m->isCache = 0;
     return m;
 }
 
@@ -25,44 +26,82 @@ void freeMigrateObj(migrateObj *m) {
     mobj = NULL;
 }
 
-int sendReplCommand(RedisModuleCtx *ctx, char *format, ...) {
-    va_list ap;
-    va_start(ap, format);
-    redisReply *reply = redisvCommand(mobj->source_cc, format, ap);
-    va_end(ap);
-    if (reply == NULL || reply->type == REDIS_REPLY_ERROR) {
-        RedisModule_Log(ctx, REDISMODULE_LOGLEVEL_WARNING, "send %s failed ip:%s,port:%d, error:%s",
-                        format, mobj->host, mobj->port, reply->str);
-        freeReplyObject(reply);
+int sendSyncCommand(RedisModuleCtx *ctx) {
+
+    if (!mobj->isCache) {
+        mobj->isCache = 1;
+        mobj->psync_replid = "?";
+        memcpy(mobj->psync_offset, "-1", 3);
+    }
+    if (redisAppendCommand(mobj->source_cc, "PSYNC %s %s", mobj->psync_replid, mobj->psync_offset) != REDIS_OK) {
+        RedisModule_Log(ctx, REDISMODULE_LOGLEVEL_WARNING,
+                        "append PSYNC %s %s failed ip:%s,port:%d, ",
+                        mobj->psync_replid, mobj->psync_offset, mobj->host, mobj->port);
         return 0;
     }
-    RedisModule_Log(ctx, REDISMODULE_LOGLEVEL_NOTICE, "%s %s", format, reply->str);
-    freeReplyObject(reply);
+    if (redisFlush(mobj->source_cc) != REDIS_OK) {
+        RedisModule_Log(ctx, REDISMODULE_LOGLEVEL_WARNING,
+                        "send PSYNC %s %s failed ip:%s,port:%d, ",
+                        mobj->psync_replid, mobj->psync_offset, mobj->host, mobj->port);
+        return 0;
+    }
+    RedisModule_Log(ctx, REDISMODULE_LOGLEVEL_NOTICE, "PSYNC %s %s ",
+                    mobj->psync_replid, mobj->psync_offset);
     return 1;
 }
 
 void *syncWithRedis(void *arg) {
     RedisModuleCtx *ctx = arg;
+    redisReply *reply;
     RedisModule_Log(ctx, REDISMODULE_LOGLEVEL_NOTICE, "begin sync data");
-    if (!sendReplCommand(ctx, "PING")) {
+    reply = redisCommand(mobj->source_cc, "PING");
+    if (reply->type == REDIS_REPLY_ERROR) {
+        RedisModule_Log(ctx, REDISMODULE_LOGLEVEL_WARNING, "send PING failed ip:%s,port:%d, error:%s",
+                        mobj->host, mobj->port, reply->str);
         goto error;
     }
+    RedisModule_Log(ctx, REDISMODULE_LOGLEVEL_NOTICE, "PING ");
+    freeReplyObject(reply);
     //todo auth with master
     sds portstr = sdsfromlonglong(mobj->port);
-    if (!sendReplCommand(ctx, "REPLCONF listening-port %s", portstr)) {
+    reply = redisCommand(mobj->source_cc, "REPLCONF listening-port %s", portstr);
+    if (reply->type == REDIS_REPLY_ERROR) {
         sdsfree(portstr);
+        RedisModule_Log(ctx, REDISMODULE_LOGLEVEL_WARNING, "REPLCONF listening-port %s failed ip:%s,port:%d, error:%s",
+                        portstr, mobj->host, mobj->port, reply->str);
         goto error;
     }
+    RedisModule_Log(ctx, REDISMODULE_LOGLEVEL_NOTICE, "REPLCONF listening-port %s ", portstr);
     sdsfree(portstr);
-    if (!sendReplCommand(ctx, "REPLCONF ip-address %s", mobj->host)) {
+    freeReplyObject(reply);
+    reply = redisCommand(mobj->source_cc, "REPLCONF ip-address %s", mobj->host);
+    if (reply->type == REDIS_REPLY_ERROR) {
+        RedisModule_Log(ctx, REDISMODULE_LOGLEVEL_WARNING, "REPLCONF ip-address %s failed ip:%s,port:%d, error:%s",
+                        mobj->host, mobj->host, mobj->port, reply->str);
         goto error;
     }
-    if (!sendReplCommand(ctx, "REPLCONF %s %s %s %s", "capa", "eof", "capa", "psync2")) {
+    RedisModule_Log(ctx, REDISMODULE_LOGLEVEL_NOTICE, "REPLCONF ip-address %s ", mobj->host);
+    freeReplyObject(reply);
+    reply = redisCommand(mobj->source_cc, "REPLCONF %s %s %s %s", "capa", "eof", "capa", "psync2");
+    if (reply->type == REDIS_REPLY_ERROR) {
+        RedisModule_Log(ctx, REDISMODULE_LOGLEVEL_WARNING,
+                        "REPLCONF capa eof capa psync2 failed ip:%s,port:%d, error:%s",
+                        mobj->host, mobj->port, reply->str);
+        goto error;
+    }
+    RedisModule_Log(ctx, REDISMODULE_LOGLEVEL_NOTICE, "REPLCONF %s %s %s %s",
+                    "capa", "eof", "capa", "psync2");
+    freeReplyObject(reply);
+    if (!sendSyncCommand(ctx)) {
+        RedisModule_Log(ctx, REDISMODULE_LOGLEVEL_WARNING,
+                        "send PSYNC %s %s failed ip:%s,port:%d, ",
+                        mobj->psync_replid, mobj->psync_offset, mobj->host, mobj->port);
         goto error;
     }
 
     return NULL;
     error:
+    freeReplyObject(reply);
     freeMigrateObj(mobj);
     return NULL;
 }
diff --git a/src/redis-migrate.h b/src/redis-migrate.h
index 57f786f..ede2ef3 100644
--- a/src/redis-migrate.h
+++ b/src/redis-migrate.h
@@ -35,6 +35,7 @@ typedef struct migrateObject {
     int begin_slot;
     int end_slot;
     char *psync_replid;
+    int isCache;
     char psync_offset[32];
 } migrateObj;
 
@@ -64,7 +65,7 @@ migrateObj *createMigrateObject(robj *host, int port, int begin_slot, int end_sl
 
 void freeMigrateObj(migrateObj *m);
 
-int sendReplCommand(RedisModuleCtx *ctx, char *format, ...);
+int sendSyncCommand(RedisModuleCtx *ctx);
 
 void *syncWithRedis(void *arg);