[TD-468] the first version of tables' allocation

src/common/inc/tglobal.h

@@ -68,6 +68,7 @@ extern int64_t tsMaxRetentWindow;
 extern int32_t tsCacheBlockSize;
 extern int32_t tsBlocksPerVnode;
 extern int32_t tsMaxTablePerVnode;
+extern int32_t tsMaxVgroupsPerDb;
 extern int16_t tsDaysPerFile;
 extern int32_t tsDaysToKeep;
 extern int32_t tsMinRowsInFileBlock;

src/common/src/tglobal.c

@@ -109,13 +109,8 @@ int32_t tsTimePrecision = TSDB_DEFAULT_PRECISION;
 int16_t tsCompression   = TSDB_DEFAULT_COMP_LEVEL;
 int16_t tsWAL           = TSDB_DEFAULT_WAL_LEVEL;
 int32_t tsReplications  = TSDB_DEFAULT_REPLICA_NUM;
-
-#ifdef _TD_ARM_32_
-  int32_t tsMaxTablePerVnode = 100;
-#else
-  int32_t tsMaxTablePerVnode = TSDB_DEFAULT_TABLES;
-#endif
-
+int32_t tsMaxVgroupsPerDb  = 0;
+int32_t tsMaxTablePerVnode = TSDB_DEFAULT_TABLES;
 // balance
 int32_t tsEnableBalance = 1;
 int32_t tsAlternativeRole = 0;
@@ -594,6 +589,16 @@ static void doInitGlobalConfig() {
   cfg.unitType = TAOS_CFG_UTYPE_NONE;
   taosInitConfigOption(cfg);
 
+  cfg.option = "maxVgroupsPerDb";
+  cfg.ptr = &tsMaxVgroupsPerDb;
+  cfg.valType = TAOS_CFG_VTYPE_INT32;
+  cfg.cfgType = TSDB_CFG_CTYPE_B_CONFIG | TSDB_CFG_CTYPE_B_SHOW;
+  cfg.minValue = 0;
+  cfg.maxValue = 8192;
+  cfg.ptrLength = 0;
+  cfg.unitType = TAOS_CFG_UTYPE_NONE;
+  taosInitConfigOption(cfg);
+
   // database configs
   cfg.option = "maxtablesPerVnode";
   cfg.ptr = &tsMaxTablePerVnode;

src/inc/taosdef.h

@@ -271,8 +271,9 @@ void tsDataSwap(void *pLeft, void *pRight, int32_t type, int32_t size);
 #define TSDB_DEFAULT_TOTAL_BLOCKS       4
 
 #define TSDB_MIN_TABLES                 4
-#define TSDB_MAX_TABLES                 200000
-#define TSDB_DEFAULT_TABLES             1000
+#define TSDB_MAX_TABLES                 5000000
+#define TSDB_DEFAULT_TABLES             500000
+#define TSDB_TABLES_STEP                10000
 
 #define TSDB_MIN_DAYS_PER_FILE          1
 #define TSDB_MAX_DAYS_PER_FILE          3650 

src/mnode/inc/mnodeDb.h

@@ -44,10 +44,7 @@ void mnodeRemoveSuperTableFromDb(SDbObj *pDb);
 void mnodeAddTableIntoDb(SDbObj *pDb);
 void mnodeRemoveTableFromDb(SDbObj *pDb);
 void mnodeAddVgroupIntoDb(SVgObj *pVgroup);
-void mnodeAddVgroupIntoDbTail(SVgObj *pVgroup);
 void mnodeRemoveVgroupFromDb(SVgObj *pVgroup);
-void mnodeMoveVgroupToTail(SVgObj *pVgroup);
-void mnodeMoveVgroupToHead(SVgObj *pVgroup);
 
 #ifdef __cplusplus
 }

src/mnode/inc/mnodeDef.h

@@ -144,10 +144,8 @@ typedef struct SVgObj {
   int64_t        totalStorage;
   int64_t        compStorage;
   int64_t        pointsWritten;
-  struct SVgObj *prev, *next;
   struct SDbObj *pDb;
   void *         idPool;
-  SChildTableObj **tableList;
 } SVgObj;
 
 typedef struct {
@@ -182,9 +180,11 @@ typedef struct SDbObj {
   int32_t numOfVgroups;
   int32_t numOfTables;
   int32_t numOfSuperTables;
-  SVgObj *pHead;
-  SVgObj *pTail;
+  int32_t vgListSize; 
+  int32_t vgListIndex;
+  SVgObj **vgList;
   struct SAcctObj *pAcct;
+  pthread_mutex_t  mutex;
 } SDbObj;
 
 typedef struct SUserObj {
@@ -245,7 +245,8 @@ typedef struct {
   int16_t  offset[TSDB_MAX_COLUMNS];
   int16_t  bytes[TSDB_MAX_COLUMNS];
   int32_t  numOfReads;
-  int8_t   reserved0[2];
+  int8_t   maxReplica;
+  int8_t   reserved0[0];
   uint16_t payloadLen;
   char     payload[];
 } SShowObj;

src/mnode/inc/mnodeDnode.h

@@ -40,6 +40,7 @@ char*   mnodeGetDnodeStatusStr(int32_t dnodeStatus);
 void    mgmtMonitorDnodeModule();
 
 int32_t mnodeGetDnodesNum();
+int32_t mnodeGetOnlinDnodesCpuCoreNum();
 int32_t mnodeGetOnlinDnodesNum();
 void *  mnodeGetNextDnode(void *pIter, SDnodeObj **pDnode);
 void    mnodeIncDnodeRef(SDnodeObj *pDnode);

src/mnode/inc/mnodeVgroup.h

@@ -30,17 +30,17 @@ void    mnodeDecVgroupRef(SVgObj *pVgroup);
 void    mnodeDropAllDbVgroups(SDbObj *pDropDb);
 void    mnodeSendDropAllDbVgroupsMsg(SDbObj *pDropDb);
 void    mnodeDropAllDnodeVgroups(SDnodeObj *pDropDnode);
-void    mnodeUpdateAllDbVgroups(SDbObj *pAlterDb);
+//void  mnodeUpdateAllDbVgroups(SDbObj *pAlterDb);
 
 void *  mnodeGetNextVgroup(void *pIter, SVgObj **pVgroup);
 void    mnodeUpdateVgroup(SVgObj *pVgroup);
 void    mnodeUpdateVgroupStatus(SVgObj *pVgroup, SDnodeObj *pDnode, SVnodeLoad *pVload);
 void    mnodeCheckUnCreatedVgroup(SDnodeObj *pDnode, SVnodeLoad *pVloads, int32_t openVnodes);
 
-int32_t mnodeCreateVgroup(struct SMnodeMsg *pMsg, SDbObj *pDb);
+int32_t mnodeCreateVgroup(struct SMnodeMsg *pMsg);
 void    mnodeDropVgroup(SVgObj *pVgroup, void *ahandle);
 void    mnodeAlterVgroup(SVgObj *pVgroup, void *ahandle);
-SVgObj *mnodeGetAvailableVgroup(SDbObj *pDb);
+int32_t mnodeGetAvailableVgroup(struct SMnodeMsg *pMsg, SVgObj **pVgroup, int32_t *sid);
 
 void    mnodeAddTableIntoVgroup(SVgObj *pVgroup, SChildTableObj *pTable);
 void    mnodeRemoveTableFromVgroup(SVgObj *pVgroup, SChildTableObj *pTable);

src/mnode/src/mnodeDb.c

@@ -38,6 +38,7 @@
 #include "mnodeUser.h"
 #include "mnodeVgroup.h"
 
+#define VG_LIST_SIZE 1
 static void *  tsDbSdb = NULL;
 static int32_t tsDbUpdateSize;
 
@@ -50,8 +51,14 @@ static int32_t mnodeProcessCreateDbMsg(SMnodeMsg *pMsg);
 static int32_t mnodeProcessAlterDbMsg(SMnodeMsg *pMsg);
 static int32_t mnodeProcessDropDbMsg(SMnodeMsg *pMsg);
 
+static void mnodeDestroyDb(SDbObj *pDb) {
+  pthread_mutex_destroy(&pDb->mutex);
+  tfree(pDb->vgList);
+  tfree(pDb);
+}
+
 static int32_t mnodeDbActionDestroy(SSdbOper *pOper) {
-  tfree(pOper->pObj);
+  mnodeDestroyDb(pOper->pObj);
   return TSDB_CODE_SUCCESS;
 }
 
@@ -59,8 +66,9 @@ static int32_t mnodeDbActionInsert(SSdbOper *pOper) {
   SDbObj *pDb = pOper->pObj;
   SAcctObj *pAcct = mnodeGetAcct(pDb->acct);
 
-  pDb->pHead = NULL;
-  pDb->pTail = NULL;
+  pthread_mutex_init(&pDb->mutex, NULL);
+  pDb->vgListSize = VG_LIST_SIZE;
+  pDb->vgList = calloc(pDb->vgListSize, sizeof(SVgObj *));
   pDb->numOfVgroups = 0;
   pDb->numOfTables = 0;
   pDb->numOfSuperTables = 0;
@@ -94,14 +102,15 @@ static int32_t mnodeDbActionDelete(SSdbOper *pOper) {
 }
 
 static int32_t mnodeDbActionUpdate(SSdbOper *pOper) {
-  SDbObj *pDb = pOper->pObj;
-  SDbObj *pSaved = mnodeGetDb(pDb->name);
-  if (pDb != pSaved) {
-    memcpy(pSaved, pDb, pOper->rowSize);
-    free(pDb);
-  }
-  mnodeUpdateAllDbVgroups(pSaved);
-  mnodeDecDbRef(pSaved);
+  SDbObj *pNew = pOper->pObj;
+  SDbObj *pDb = mnodeGetDb(pNew->name);
+  if (pDb != NULL && pNew != pDb) {
+    memcpy(pDb, pNew, pOper->rowSize);
+    free(pNew->vgList);
+    free(pNew);
+  }
+  //mnodeUpdateAllDbVgroups(pDb);
+  mnodeDecDbRef(pDb);
   return TSDB_CODE_SUCCESS;
 }
 
@@ -416,45 +425,33 @@ void mnodePrintVgroups(SDbObj *pDb, char *oper) {
 void mnodeAddVgroupIntoDb(SVgObj *pVgroup) {
   SDbObj *pDb = pVgroup->pDb;
 
-  pVgroup->next = pDb->pHead;
-  pVgroup->prev = NULL;
-
-  if (pDb->pHead) pDb->pHead->prev = pVgroup;
-  if (pDb->pTail == NULL) pDb->pTail = pVgroup;
-
-  pDb->pHead = pVgroup;
-  pDb->numOfVgroups++;
-}
-
-void mnodeAddVgroupIntoDbTail(SVgObj *pVgroup) {
-  SDbObj *pDb = pVgroup->pDb;
-  pVgroup->next = NULL;
-  pVgroup->prev = pDb->pTail;
-
-  if (pDb->pTail) pDb->pTail->next = pVgroup;
-  if (pDb->pHead == NULL) pDb->pHead = pVgroup;
+  pthread_mutex_lock(&pDb->mutex);
+  int32_t vgPos = pDb->numOfVgroups++;
+  if (vgPos >= pDb->vgListSize) {
+    pDb->vgList = realloc(pDb->vgList, pDb->vgListSize * 2 * sizeof(SVgObj *));
+    memset(pDb->vgList + pDb->vgListSize, 0, pDb->vgListSize * sizeof(SVgObj *));
+    pDb->vgListSize *= 2;
+  }
 
-  pDb->pTail = pVgroup;
-  pDb->numOfVgroups++;
+  pDb->vgList[vgPos] = pVgroup;
+  pthread_mutex_lock(&pDb->mutex);
 }
 
 void mnodeRemoveVgroupFromDb(SVgObj *pVgroup) {
   SDbObj *pDb = pVgroup->pDb;
-  if (pVgroup->prev) pVgroup->prev->next = pVgroup->next;
-  if (pVgroup->next) pVgroup->next->prev = pVgroup->prev;
-  if (pVgroup->prev == NULL) pDb->pHead = pVgroup->next;
-  if (pVgroup->next == NULL) pDb->pTail = pVgroup->prev;
-  pDb->numOfVgroups--;
-}
 
-void mnodeMoveVgroupToTail(SVgObj *pVgroup) {
-  mnodeRemoveVgroupFromDb(pVgroup);
-  mnodeAddVgroupIntoDbTail(pVgroup);
-}
+  pthread_mutex_lock(&pDb->mutex);
+  for (int32_t v1 = 0; v1 < pDb->numOfVgroups; ++v1) {
+    if (pDb->vgList[v1] == pVgroup) {
+      for (int32_t v2 = v1; v2 < pDb->numOfVgroups - 1; ++v2) {
+        pDb->vgList[v2] = pDb->vgList[v2 + 1];
+      }
+      pDb->numOfVgroups--;
+      break;
+    }
+  }
 
-void mnodeMoveVgroupToHead(SVgObj *pVgroup) {
-  mnodeRemoveVgroupFromDb(pVgroup);
-  mnodeAddVgroupIntoDb(pVgroup);
+  pthread_mutex_lock(&pDb->mutex);
 }
 
 void mnodeCleanupDbs() {
@@ -525,11 +522,6 @@ static int32_t mnodeGetDbMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn
 #ifndef __CLOUD_VERSION__
   if (strcmp(pUser->user, TSDB_DEFAULT_USER) == 0) {
 #endif
-    pShow->bytes[cols] = 4;
-    pSchema[cols].type = TSDB_DATA_TYPE_INT;
-    strcpy(pSchema[cols].name, "maxtables");
-    pSchema[cols].bytes = htons(pShow->bytes[cols]);
-    cols++;
 
     pShow->bytes[cols] = 4;
     pSchema[cols].type = TSDB_DATA_TYPE_INT;
@@ -555,12 +547,6 @@ static int32_t mnodeGetDbMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn
     pSchema[cols].bytes = htons(pShow->bytes[cols]);
     cols++;
 
-    pShow->bytes[cols] = 4;
-    pSchema[cols].type = TSDB_DATA_TYPE_INT;
-    strcpy(pSchema[cols].name, "ctime(Sec.)");
-    pSchema[cols].bytes = htons(pShow->bytes[cols]);
-    cols++;
-
     pShow->bytes[cols] = 1;
     pSchema[cols].type = TSDB_DATA_TYPE_TINYINT;
     strcpy(pSchema[cols].name, "wallevel");
@@ -670,10 +656,6 @@ static int32_t mnodeRetrieveDbs(SShowObj *pShow, char *data, int32_t rows, void
 #ifndef __CLOUD_VERSION__
     if (strcmp(pUser->user, TSDB_DEFAULT_USER) == 0) {
 #endif
-      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-      *(int32_t *)pWrite = pDb->cfg.maxTables;  // table num can be created should minus 1
-      cols++;
-
       pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
       *(int32_t *)pWrite = pDb->cfg.cacheBlockSize;
       cols++;
@@ -690,10 +672,6 @@ static int32_t mnodeRetrieveDbs(SShowObj *pShow, char *data, int32_t rows, void
       *(int32_t *)pWrite = pDb->cfg.maxRowsPerFileBlock;
       cols++;
       
-      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-      *(int32_t *)pWrite = pDb->cfg.commitTime;
-      cols++;
-
       pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
       *(int8_t *)pWrite = pDb->cfg.walLevel;
       cols++;

src/mnode/src/mnodeDnode.c

@@ -186,7 +186,27 @@ int32_t mnodeGetDnodesNum() {
   return sdbGetNumOfRows(tsDnodeSdb);
 }
 
-int32_t mnodeGetOnlinDnodesNum(char *ep) {
+int32_t mnodeGetOnlinDnodesCpuCoreNum() {
+  SDnodeObj *pDnode = NULL;
+  void *     pIter = NULL;
+  int32_t    cpuCores = 0;
+
+  while (1) {
+    pIter = mnodeGetNextDnode(pIter, &pDnode);
+    if (pDnode == NULL) break;
+    if (pDnode->status != TAOS_DN_STATUS_OFFLINE) {
+      cpuCores += pDnode->numOfCores;
+    }
+    mnodeDecDnodeRef(pDnode);
+  }
+
+  sdbFreeIter(pIter);
+
+  if (cpuCores < 2) cpuCores = 2;
+  return cpuCores;
+}
+
+int32_t mnodeGetOnlinDnodesNum() {
   SDnodeObj *pDnode = NULL;
   void *     pIter = NULL;
   int32_t    onlineDnodes = 0;

src/mnode/src/mnodeTable.c

@@ -314,15 +314,6 @@ static int32_t mnodeChildTableActionRestored() {
       continue;
     }
 
-    if (pVgroup->tableList == NULL) {
-      mError("ctable:%s, vgId:%d tableList is null", pTable->info.tableId, pTable->vgId);
-      pTable->vgId = 0;
-      SSdbOper desc = {.type = SDB_OPER_LOCAL, .pObj = pTable, .table = tsChildTableSdb};
-      sdbDeleteRow(&desc);
-      mnodeDecTableRef(pTable);
-      continue;
-    }
-
     if (pTable->info.type == TSDB_CHILD_TABLE) {
       SSuperTableObj *pSuperTable = mnodeGetSuperTableByUid(pTable->suid);
       if (pSuperTable == NULL) {
@@ -1686,19 +1677,15 @@ static int32_t mnodeProcessCreateChildTableMsg(SMnodeMsg *pMsg) {
     return code;
   }
 
-  SVgObj *pVgroup = mnodeGetAvailableVgroup(pMsg->pDb);
-  if (pVgroup == NULL) {
-    mDebug("app:%p:%p, table:%s, start to create a new vgroup", pMsg->rpcMsg.ahandle, pMsg, pCreate->tableId);
-    return mnodeCreateVgroup(pMsg, pMsg->pDb);
-  }
-
   if (pMsg->retry == 0) {
     if (pMsg->pTable == NULL) {
-      int32_t sid = taosAllocateId(pVgroup->idPool);
-      if (sid <= 0) {
-        mDebug("app:%p:%p, table:%s, no enough sid in vgId:%d", pMsg->rpcMsg.ahandle, pMsg, pCreate->tableId,
-               pVgroup->vgId);
-        return mnodeCreateVgroup(pMsg, pMsg->pDb);
+      SVgObj *pVgroup;
+      int32_t sid;
+      code = mnodeGetAvailableVgroup(pMsg, &pVgroup, &sid);
+      if (code != TSDB_CODE_SUCCESS) {
+        mDebug("app:%p:%p, table:%s, failed to get available vgroup, reason:%s", pMsg->rpcMsg.ahandle, pMsg,
+               pCreate->tableId, tstrerror(code));
+        return code;
       }
 
       if (pMsg->pVgroup == NULL) {
@@ -2105,6 +2092,7 @@ static void mnodeDropAllChildTablesInStable(SSuperTableObj *pStable) {
   mInfo("stable:%s, all child tables:%d is dropped from sdb", pStable->info.tableId, numOfTables);
 }
 
+#if 0
 static SChildTableObj* mnodeGetTableByPos(int32_t vnode, int32_t sid) {
   SVgObj *pVgroup = mnodeGetVgroup(vnode);
   if (pVgroup == NULL) return NULL;
@@ -2115,8 +2103,11 @@ static SChildTableObj* mnodeGetTableByPos(int32_t vnode, int32_t sid) {
   mnodeDecVgroupRef(pVgroup);
   return pTable;
 }
+#endif
 
 static int32_t mnodeProcessTableCfgMsg(SMnodeMsg *pMsg) {
+  return TSDB_CODE_COM_OPS_NOT_SUPPORT;
+#if 0  
   SDMConfigTableMsg *pCfg = pMsg->rpcMsg.pCont;
   pCfg->dnodeId = htonl(pCfg->dnodeId);
   pCfg->vgId = htonl(pCfg->vgId);
@@ -2140,6 +2131,7 @@ static int32_t mnodeProcessTableCfgMsg(SMnodeMsg *pMsg) {
   pMsg->rpcRsp.rsp = pCreate;
   pMsg->rpcRsp.len = htonl(pCreate->contLen);
   return TSDB_CODE_SUCCESS;
+#endif  
 }
 
 // handle drop child response

src/mnode/src/mnodeVgroup.c

@@ -41,6 +41,7 @@
 static void   *tsVgroupSdb = NULL;
 static int32_t tsVgUpdateSize = 0;
 
+static int32_t mnodeAllocVgroupIdPool(SVgObj *pInputVgroup);
 static int32_t mnodeGetVgroupMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn);
 static int32_t mnodeRetrieveVgroups(SShowObj *pShow, char *data, int32_t rows, void *pConn);
 static void    mnodeProcessCreateVnodeRsp(SRpcMsg *rpcMsg);
@@ -54,9 +55,6 @@ static int32_t mnodeVgroupActionDestroy(SSdbOper *pOper) {
     taosIdPoolCleanUp(pVgroup->idPool);
     pVgroup->idPool = NULL;
   }
-  if (pVgroup->tableList) {
-    tfree(pVgroup->tableList);
-  }
 
   tfree(pOper->pObj);
   return TSDB_CODE_SUCCESS;
@@ -72,21 +70,9 @@ static int32_t mnodeVgroupActionInsert(SSdbOper *pOper) {
   }
 
   pVgroup->pDb = pDb;
-  pVgroup->prev = NULL;
-  pVgroup->next = NULL;
   pVgroup->accessState = TSDB_VN_ALL_ACCCESS;
-
-  int32_t size = sizeof(SChildTableObj *) * pDb->cfg.maxTables;
-  pVgroup->tableList = calloc(pDb->cfg.maxTables, sizeof(SChildTableObj *));
-  if (pVgroup->tableList == NULL) {
-    mError("vgId:%d, failed to malloc(size:%d) for the tableList of vgroups", pVgroup->vgId, size);
-    return -1;
-  }
-
-  pVgroup->idPool = taosInitIdPool(pDb->cfg.maxTables);
-  if (pVgroup->idPool == NULL) {
-    mError("vgId:%d, failed to taosInitIdPool for vgroups", pVgroup->vgId);
-    tfree(pVgroup->tableList);
+  if (mnodeAllocVgroupIdPool(pVgroup) < 0) {
+    mError("vgId:%d, failed to init idpool for vgroups", pVgroup->vgId);
     return -1;
   }
 
@@ -124,20 +110,6 @@ static int32_t mnodeVgroupActionDelete(SSdbOper *pOper) {
   return TSDB_CODE_SUCCESS;
 }
 
-static void mnodeVgroupUpdateIdPool(SVgObj *pVgroup) {
-  int32_t oldTables = taosIdPoolMaxSize(pVgroup->idPool);
-  SDbObj *pDb = pVgroup->pDb;
-  if (pDb != NULL) {
-    if (pDb->cfg.maxTables != oldTables) {
-      mInfo("vgId:%d tables change from %d to %d", pVgroup->vgId, oldTables, pDb->cfg.maxTables);
-      taosUpdateIdPool(pVgroup->idPool, pDb->cfg.maxTables);
-      int32_t size = sizeof(SChildTableObj *) * pDb->cfg.maxTables;
-      pVgroup->tableList = (SChildTableObj **)realloc(pVgroup->tableList, size);
-      memset(pVgroup->tableList + oldTables, 0, (pDb->cfg.maxTables - oldTables) * sizeof(SChildTableObj *));
-    }
-  }
-}
-
 static int32_t mnodeVgroupActionUpdate(SSdbOper *pOper) {
   SVgObj *pNew = pOper->pObj;
   SVgObj *pVgroup = mnodeGetVgroup(pNew->vgId);
@@ -162,8 +134,6 @@ static int32_t mnodeVgroupActionUpdate(SSdbOper *pOper) {
     }
   }
 
-  mnodeVgroupUpdateIdPool(pVgroup);
-
   mnodeDecVgroupRef(pVgroup);
 
   mDebug("vgId:%d, is updated, numOfVnode:%d", pVgroup->vgId, pVgroup->numOfVnodes);
@@ -325,8 +295,122 @@ void mnodeUpdateVgroupStatus(SVgObj *pVgroup, SDnodeObj *pDnode, SVnodeLoad *pVl
   }
 }
 
-SVgObj *mnodeGetAvailableVgroup(SDbObj *pDb) {
-  return pDb->pHead;
+static int32_t mnodeAllocVgroupIdPool(SVgObj *pInputVgroup) {
+  SDbObj *pDb = pInputVgroup->pDb;
+  if (pDb == NULL) return TSDB_CODE_MND_APP_ERROR;
+
+  int32_t currIdPoolSize = TSDB_MIN_TABLES;
+  for (int32_t v = 0; v < pDb->numOfVgroups; ++v) {
+    SVgObj *pVgroup = pDb->vgList[v];
+    if (pVgroup == NULL) continue;
+
+    int32_t idPoolSize = taosIdPoolMaxSize(pVgroup->idPool);
+    currIdPoolSize = MAX(currIdPoolSize, idPoolSize);
+  }
+
+  // new vgroup
+  if (pInputVgroup->idPool == NULL) {
+    pInputVgroup->idPool = taosInitIdPool(currIdPoolSize);
+    if (pInputVgroup->idPool == NULL) {
+      mError("vgId:%d, failed to init idPool for vgroup, size:%d", pInputVgroup->vgId, currIdPoolSize);
+      return TSDB_CODE_MND_OUT_OF_MEMORY;
+    } else {
+      mDebug("vgId:%d, init idPool for vgroup, size:%d", pInputVgroup->vgId, currIdPoolSize);
+      return TSDB_CODE_SUCCESS;
+    }
+  }
+
+  // realloc all vgroups in db
+  int32_t newIdPoolSize;
+  if (currIdPoolSize < TSDB_TABLES_STEP) {
+    newIdPoolSize = currIdPoolSize * 2;
+  } else {
+    newIdPoolSize = ((currIdPoolSize / TSDB_TABLES_STEP) + 1) * TSDB_TABLES_STEP;
+  }
+
+  if (newIdPoolSize > tsMaxTablePerVnode) {
+    mDebug("db:%s, currIdPoolSize:%d newIdPoolSize%d larger than %d", pDb->name, currIdPoolSize, newIdPoolSize,
+           tsMaxTablePerVnode);
+    return TSDB_CODE_MND_NO_ENOUGH_DNODES;
+  }
+
+  for (int32_t v = 0; v < pDb->numOfVgroups; ++v) {
+    SVgObj *pVgroup = pDb->vgList[v];
+    if (pVgroup == NULL) continue;
+
+    int32_t oldIdPoolSize = taosIdPoolMaxSize(pVgroup->idPool);
+
+    if (taosUpdateIdPool(pVgroup->idPool, newIdPoolSize) < 0) {
+      mError("vgId:%d, failed to update idPoolSize from %d to %d", pVgroup->vgId, oldIdPoolSize, newIdPoolSize);
+      return TSDB_CODE_MND_NO_ENOUGH_DNODES;
+    } else {
+      mDebug("vgId:%d, idPoolSize update from %d to %d", pVgroup->vgId, oldIdPoolSize, newIdPoolSize);
+    }
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+int32_t mnodeGetAvailableVgroup(SMnodeMsg *pMsg, SVgObj **ppVgroup, int32_t *pSid) {
+  SDbObj *pDb = pMsg->pDb;
+  pthread_mutex_lock(&pDb->mutex);
+  
+  for (int32_t v = 0; v < pDb->numOfVgroups; ++v) {
+    int vgIndex = (v + pDb->vgListIndex) % pDb->numOfVgroups;
+    SVgObj *pVgroup = pDb->vgList[vgIndex];
+    if (pVgroup == NULL) {
+      mError("db:%s, index:%d vgroup is null", pDb->name, vgIndex);
+      pthread_mutex_unlock(&pDb->mutex);
+      return TSDB_CODE_MND_APP_ERROR;
+    }
+
+    int32_t sid = taosAllocateId(pVgroup->idPool);
+    if (sid <= 0) {
+      mDebug("app:%p:%p, db:%s, no enough sid in vgId:%d", pMsg->rpcMsg.ahandle, pMsg, pDb->name, pVgroup->vgId);
+      continue;
+    }
+
+    *pSid = sid;
+    *ppVgroup = pVgroup;
+    pDb->vgListIndex = vgIndex;
+
+    pthread_mutex_unlock(&pDb->mutex);
+    return TSDB_CODE_SUCCESS;
+  }
+
+  int maxVgroupsPerDb = tsMaxVgroupsPerDb;
+  if (maxVgroupsPerDb <= 0) {
+    maxVgroupsPerDb = mnodeGetOnlinDnodesCpuCoreNum();
+    maxVgroupsPerDb = MIN(maxVgroupsPerDb, 2);
+  }
+
+  if (pDb->numOfVgroups < maxVgroupsPerDb) {
+    mDebug("app:%p:%p, db:%s, start to create a new vgroup, numOfVgroups:%d maxVgroupsPerDb:%d", pMsg->rpcMsg.ahandle, pMsg,
+           pDb->name, pDb->numOfVgroups, maxVgroupsPerDb);
+    pthread_mutex_unlock(&pDb->mutex);
+    return mnodeCreateVgroup(pMsg);
+  } 
+
+  SVgObj *pVgroup = pDb->vgList[0];
+  int32_t code = mnodeAllocVgroupIdPool(pVgroup);
+  if (code != TSDB_CODE_SUCCESS) {
+    pthread_mutex_unlock(&pDb->mutex);
+    return code;
+  }
+
+  int32_t sid = taosAllocateId(pVgroup->idPool);
+  if (sid <= 0) {
+    mError("app:%p:%p, db:%s, no enough sid in vgId:%d", pMsg->rpcMsg.ahandle, pMsg, pDb->name, pVgroup->vgId);
+    pthread_mutex_unlock(&pDb->mutex);
+    return TSDB_CODE_MND_NO_ENOUGH_DNODES;
+  }
+
+  *pSid = sid;
+  *ppVgroup = pVgroup;
+  pDb->vgListIndex = 0;
+  pthread_mutex_unlock(&pDb->mutex);
+
+  return TSDB_CODE_SUCCESS;
 }
 
 void *mnodeGetNextVgroup(void *pIter, SVgObj **pVgroup) { 
@@ -354,8 +438,9 @@ static int32_t mnodeCreateVgroupCb(SMnodeMsg *pMsg, int32_t code) {
   return TSDB_CODE_MND_ACTION_IN_PROGRESS;
 }
 
-int32_t mnodeCreateVgroup(SMnodeMsg *pMsg, SDbObj *pDb) {
+int32_t mnodeCreateVgroup(SMnodeMsg *pMsg) {
   if (pMsg == NULL) return TSDB_CODE_MND_APP_ERROR;
+  SDbObj *pDb = pMsg->pDb;
 
   SVgObj *pVgroup = (SVgObj *)calloc(1, sizeof(SVgObj));
   tstrncpy(pVgroup->dbName, pDb->name, TSDB_ACCT_LEN + TSDB_DB_NAME_LEN);
@@ -430,29 +515,21 @@ int32_t mnodeGetVgroupMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
   pSchema[cols].bytes = htons(pShow->bytes[cols]);
   cols++;
 
-  int32_t maxReplica = 0;
-  SVgObj  *pVgroup   = NULL;
-  STableObj *pTable = NULL;
-  if (pShow->payloadLen > 0 ) {
-    pTable = mnodeGetTable(pShow->payload);
-    if (NULL == pTable || pTable->type == TSDB_SUPER_TABLE) {
-      mnodeDecTableRef(pTable);
-      return TSDB_CODE_MND_INVALID_TABLE_NAME;
-    }
-    mnodeDecTableRef(pTable);
-    pVgroup = mnodeGetVgroup(((SChildTableObj*)pTable)->vgId);
-    if (NULL == pVgroup) return TSDB_CODE_MND_INVALID_TABLE_NAME;
-    mnodeDecVgroupRef(pVgroup);
-    maxReplica = pVgroup->numOfVnodes > maxReplica ? pVgroup->numOfVnodes : maxReplica;
-  } else {
-    SVgObj *pVgroup = pDb->pHead;
-    while (pVgroup != NULL) {
-      maxReplica = pVgroup->numOfVnodes > maxReplica ? pVgroup->numOfVnodes : maxReplica;
-      pVgroup = pVgroup->next;
+  pShow->bytes[cols] = 4;
+  pSchema[cols].type = TSDB_DATA_TYPE_INT;
+  strcpy(pSchema[cols].name, "maxTables");
+  pSchema[cols].bytes = htons(pShow->bytes[cols]);
+  cols++;
+
+  pShow->maxReplica = 1;
+  for (int32_t v = 0; v < pDb->numOfVgroups; ++v) {
+    SVgObj *pVgroup = pDb->vgList[v];
+    if (pVgroup != NULL) {
+      pShow->maxReplica = pVgroup->numOfVnodes > pShow->maxReplica ? pVgroup->numOfVnodes : pShow->maxReplica;
     }
   }
 
-  for (int32_t i = 0; i < maxReplica; ++i) {
+  for (int32_t i = 0; i < pShow->maxReplica; ++i) {
     pShow->bytes[cols] = 2;
     pSchema[cols].type = TSDB_DATA_TYPE_SMALLINT;
     strcpy(pSchema[cols].name, "dnode");
@@ -476,43 +553,48 @@ int32_t mnodeGetVgroupMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
   pShow->numOfColumns = cols;
 
   pShow->offset[0] = 0;
-  for (int32_t i = 1; i < cols; ++i) pShow->offset[i] = pShow->offset[i - 1] + pShow->bytes[i - 1];
-
-  pShow->rowSize = pShow->offset[cols - 1] + pShow->bytes[cols - 1];
+  for (int32_t i = 1; i < cols; ++i) {
+    pShow->offset[i] = pShow->offset[i - 1] + pShow->bytes[i - 1];
+  }
 
-  if (NULL == pTable) {
   pShow->numOfRows = pDb->numOfVgroups;
-    pShow->pIter = pDb->pHead;
-  } else {
-    pShow->numOfRows = 1;
-    pShow->pIter = pVgroup;
-  }
+  pShow->rowSize = pShow->offset[cols - 1] + pShow->bytes[cols - 1];
 
   mnodeDecDbRef(pDb);
-
   return 0;
 }
 
+static bool mnodeFilterVgroups(SVgObj *pVgroup, STableObj *pTable) {
+  if (NULL == pTable || pTable->type == TSDB_SUPER_TABLE) {
+    return true;
+  }
+
+  SChildTableObj *pCTable = (SChildTableObj *)pTable;
+  if (pVgroup->vgId == pCTable->vgId) {
+    return true;
+  } else {
+    return false;
+  }
+}
+
 int32_t mnodeRetrieveVgroups(SShowObj *pShow, char *data, int32_t rows, void *pConn) {
   int32_t numOfRows = 0;
   SVgObj *pVgroup = NULL;
-  int32_t maxReplica = 0;
   int32_t cols = 0;
   char *  pWrite;
 
   SDbObj *pDb = mnodeGetDb(pShow->db);
   if (pDb == NULL) return 0;
 
-  pVgroup = pDb->pHead;
-  while (pVgroup != NULL) {
-    maxReplica = pVgroup->numOfVnodes > maxReplica ? pVgroup->numOfVnodes : maxReplica;
-    pVgroup    = pVgroup->next;
+  STableObj *pTable = NULL;
+  if (pShow->payloadLen > 0 ) {
+    pTable = mnodeGetTable(pShow->payload);
   }
 
   while (numOfRows < rows) {
-    pVgroup = (SVgObj *) pShow->pIter;
+    pShow->pIter = mnodeGetNextVgroup(pShow->pIter, &pVgroup);
     if (pVgroup == NULL) break;
-    pShow->pIter = (void *) pVgroup->next;
+    if (!mnodeFilterVgroups(pVgroup, pTable)) continue;
 
     cols = 0;
 
@@ -524,7 +606,11 @@ int32_t mnodeRetrieveVgroups(SShowObj *pShow, char *data, int32_t rows, void *pC
     *(int32_t *) pWrite = pVgroup->numOfTables;
     cols++;
 
-    for (int32_t i = 0; i < maxReplica; ++i) {
+    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
+    *(int32_t *) pWrite = tsMaxTablePerVnode;
+    cols++;
+
+    for (int32_t i = 0; i < pShow->maxReplica; ++i) {
       pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
       *(int16_t *) pWrite = pVgroup->vnodeGid[i].dnodeId;
       cols++;
@@ -552,38 +638,36 @@ int32_t mnodeRetrieveVgroups(SShowObj *pShow, char *data, int32_t rows, void *pC
       }
     }
 
+    mnodeDecVgroupRef(pVgroup);
     numOfRows++;
   }
 
   pShow->numOfReads += numOfRows;
+  mnodeDecTableRef(pTable);
   mnodeDecDbRef(pDb);
 
   return numOfRows;
 }
 
 void mnodeAddTableIntoVgroup(SVgObj *pVgroup, SChildTableObj *pTable) {
-  if (pTable->sid >= 1 && pVgroup->tableList[pTable->sid - 1] == NULL) {
-    pVgroup->tableList[pTable->sid - 1] = pTable;
-    taosIdPoolMarkStatus(pVgroup->idPool, pTable->sid);
-    pVgroup->numOfTables++;
-  }
-  
-  if (pVgroup->numOfTables >= pVgroup->pDb->cfg.maxTables) {
-    mnodeMoveVgroupToTail(pVgroup);
+  int32_t idPoolSize = taosIdPoolMaxSize(pVgroup->idPool);
+  if (pTable->sid > idPoolSize) {
+    mnodeAllocVgroupIdPool(pVgroup);
   }
 
+  if (pTable->sid >= 1) {
+    taosIdPoolMarkStatus(pVgroup->idPool, pTable->sid);
+    pVgroup->numOfTables++;
     mnodeIncVgroupRef(pVgroup);
+  }
 }
 
 void mnodeRemoveTableFromVgroup(SVgObj *pVgroup, SChildTableObj *pTable) {
-  if (pTable->sid >= 1 && pVgroup->tableList[pTable->sid - 1] != NULL) {
-    pVgroup->tableList[pTable->sid - 1] = NULL;
+  if (pTable->sid >= 1) {
     taosFreeId(pVgroup->idPool, pTable->sid);
     pVgroup->numOfTables--;
-  }
-
-  mnodeMoveVgroupToHead(pVgroup);
     mnodeDecVgroupRef(pVgroup);
+  }
 }
 
 SMDCreateVnodeMsg *mnodeBuildCreateVnodeMsg(SVgObj *pVgroup) {
@@ -594,13 +678,14 @@ SMDCreateVnodeMsg *mnodeBuildCreateVnodeMsg(SVgObj *pVgroup) {
   if (pVnode == NULL) return NULL;
 
   strcpy(pVnode->db, pVgroup->dbName);
+  int32_t maxTables = taosIdPoolMaxSize(pVgroup->idPool);
 
   SMDVnodeCfg *pCfg = &pVnode->cfg;
   pCfg->vgId                = htonl(pVgroup->vgId);
   pCfg->cfgVersion          = htonl(pDb->cfgVersion);
   pCfg->cacheBlockSize      = htonl(pDb->cfg.cacheBlockSize);
   pCfg->totalBlocks         = htonl(pDb->cfg.totalBlocks);
-  pCfg->maxTables           = htonl(pDb->cfg.maxTables + 1);
+  pCfg->maxTables           = htonl(maxTables + 1);
   pCfg->daysPerFile         = htonl(pDb->cfg.daysPerFile);
   pCfg->daysToKeep          = htonl(pDb->cfg.daysToKeep);
   pCfg->daysToKeep1         = htonl(pDb->cfg.daysToKeep1);
@@ -822,6 +907,7 @@ void mnodeDropAllDnodeVgroups(SDnodeObj *pDropDnode) {
   mInfo("dnode:%d, all vgroups is dropped from sdb", pDropDnode->dnodeId);
 }
 
+#if 0
 void mnodeUpdateAllDbVgroups(SDbObj *pAlterDb) {
   void *  pIter = NULL;
   SVgObj *pVgroup = NULL;
@@ -843,6 +929,7 @@ void mnodeUpdateAllDbVgroups(SDbObj *pAlterDb) {
 
   mInfo("db:%s, all vgroups is updated in sdb", pAlterDb->name);
 }
+#endif
 
 void mnodeDropAllDbVgroups(SDbObj *pDropDb) {
   void *  pIter = NULL;