diff --git a/source/dnode/mgmt/impl/test/db/db.cpp b/source/dnode/mgmt/impl/test/db/db.cpp
index 89e6603d16..231c3177a5 100644
--- a/source/dnode/mgmt/impl/test/db/db.cpp
+++ b/source/dnode/mgmt/impl/test/db/db.cpp
@@ -206,6 +206,8 @@ TEST_F(DndTestDb, 01_ShowDb) {
 
 TEST_F(DndTestDb, 02_CreateDb) {
   {
+    taosMsleep(1100);
+
     SCreateDbMsg* pReq = (SCreateDbMsg*)rpcMallocCont(sizeof(SCreateDbMsg));
     strcpy(pReq->db, "1.d1");
     pReq->numOfVgroups = htonl(2);
diff --git a/source/dnode/mnode/impl/inc/mndDnode.h b/source/dnode/mnode/impl/inc/mndDnode.h
index 04ceb2820a..764dfbffc1 100644
--- a/source/dnode/mnode/impl/inc/mndDnode.h
+++ b/source/dnode/mnode/impl/inc/mndDnode.h
@@ -28,6 +28,7 @@ SDnodeObj *mndAcquireDnode(SMnode *pMnode, int32_t dnodeId);
 void       mndReleaseDnode(SMnode *pMnode, SDnodeObj *pDnode);
 SEpSet     mndGetDnodeEpset(SDnodeObj *pDnode);
 int32_t    mndGetDnodeSize(SMnode *pMnode);
+bool       mndIsDnodeInReadyStatus(SMnode *pMnode, SDnodeObj *pDnode);
 
 #ifdef __cplusplus
 }
diff --git a/source/dnode/mnode/impl/src/mndDnode.c b/source/dnode/mnode/impl/src/mndDnode.c
index ec5f68a713..791f43c69c 100644
--- a/source/dnode/mnode/impl/src/mndDnode.c
+++ b/source/dnode/mnode/impl/src/mndDnode.c
@@ -218,6 +218,15 @@ int32_t mndGetDnodeSize(SMnode *pMnode) {
   return sdbGetSize(pSdb, SDB_DNODE);
 }
 
+bool mndIsDnodeInReadyStatus(SMnode *pMnode, SDnodeObj *pDnode) {
+  int64_t ms = taosGetTimestampMs();
+  int64_t interval = ABS(pDnode->lastAccessTime - ms);
+  if (interval > 3000 * pMnode->cfg.statusInterval) {
+    return false;
+  }
+  return true;
+}
+
 static void mndGetDnodeData(SMnode *pMnode, SDnodeEps *pEps, int32_t numOfEps) {
   SSdb *pSdb = pMnode->pSdb;
 
diff --git a/source/dnode/mnode/impl/src/mndVgroup.c b/source/dnode/mnode/impl/src/mndVgroup.c
index 023171cdfe..b2a2903f09 100644
--- a/source/dnode/mnode/impl/src/mndVgroup.c
+++ b/source/dnode/mnode/impl/src/mndVgroup.c
@@ -152,18 +152,73 @@ void mndReleaseVgroup(SMnode *pMnode, SVgObj *pVgroup) {
   sdbRelease(pSdb, pVgroup);
 }
 
-static int32_t mndGetDefaultVgroupSize(SMnode *pMnode) { return 4; }
+static int32_t mndGetDefaultVgroupSize(SMnode *pMnode) {
+  // todo
+  return 2;
+}
 
-int32_t mndAllocVgroup(SMnode *pMnode, SDbObj *pDb) {
-  if (pDb->numOfVgroups == -1) {
-    pDb->numOfVgroups = mndGetDefaultVgroupSize(pMnode);
+static int32_t mndGetAvailableDnode(SMnode *pMnode, SVgObj *pVgroup) {
+  SSdb   *pSdb = pMnode->pSdb;
+  int32_t allocedVnodes = 0;
+  void   *pIter = NULL;
+
+  while (allocedVnodes < pVgroup->replica) {
+    SDnodeObj *pDnode = NULL;
+    pIter = sdbFetch(pSdb, SDB_DNODE, pIter, (void **)&pDnode);
+    if (pIter == NULL) break;
+
+    // todo
+    if (mndIsDnodeInReadyStatus(pMnode, pDnode)) {
+      SVnodeGid *pVgid = &pVgroup->vnodeGid[allocedVnodes];
+      pVgid->dnodeId = pDnode->id;
+      pVgid->role = TAOS_SYNC_STATE_FOLLOWER;
+      allocedVnodes++;
+    }
+    sdbRelease(pSdb, pDnode);
   }
 
-  if (pDb->numOfVgroups < TSDB_MIN_VNODES_PER_DB || pDb->numOfVgroups > TSDB_MAX_VNODES_PER_DB) {
+  if (allocedVnodes != pVgroup->replica) {
+    terrno = TSDB_CODE_MND_NO_ENOUGH_DNODES;
+    return -1;
+  }
+  return 0;
+}
+
+int32_t mndAllocVgroup(SMnode *pMnode, SDbObj *pDb) {
+  if (pDb->numOfVgroups != -1 &&
+      (pDb->numOfVgroups < TSDB_MIN_VNODES_PER_DB || pDb->numOfVgroups > TSDB_MAX_VNODES_PER_DB)) {
     terrno = TSDB_CODE_MND_INVALID_DB_OPTION;
     return -1;
   }
 
+  if (pDb->numOfVgroups == -1) {
+    pDb->numOfVgroups = mndGetDefaultVgroupSize(pMnode);
+    if (pDb->numOfVgroups < 0) {
+      terrno = TSDB_CODE_MND_NO_ENOUGH_DNODES;
+      return -1;
+    }
+  }
+
+  int32_t alloceVgroups = 0;
+  int32_t maxVgId = sdbGetMaxId(pMnode->pSdb, SDB_VGROUP);
+
+  while (alloceVgroups < pDb->numOfVgroups) {
+    SVgObj vgObj = {0};
+    vgObj.vgId == maxVgId++;
+    vgObj.createdTime = taosGetTimestampMs();
+    vgObj.updateTime = vgObj.createdTime;
+    vgObj.version = 0;
+    memcpy(vgObj.dbName, pDb->name, TSDB_FULL_DB_NAME_LEN);
+    vgObj.replica = pDb->cfg.replications;
+
+    if (mndGetAvailableDnode(pMnode, &vgObj) != 0) {
+      terrno = TSDB_CODE_MND_NO_ENOUGH_DNODES;
+      return -1;
+    }
+
+    alloceVgroups++;
+  }
+
   return 0;
 }