mnodeDnode.c

/*
 * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
 *
 * This program is free software: you can use, redistribute, and/or modify
 * it under the terms of the GNU Affero General Public License, version 3
 * or later ("AGPL"), as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#define _DEFAULT_SOURCE
#include "os.h"
#include "tgrant.h"
#include "tbn.h"
#include "tglobal.h"
#include "tconfig.h"
#include "tutil.h"
#include "tsocket.h"
#include "tbn.h"
#include "tsync.h"
#include "tdataformat.h"
#include "mnode.h"
#include "dnode.h"
#include "mnodeDef.h"
#include "mnodeInt.h"
#include "mnodeDnode.h"
#include "mnodeMnode.h"
#include "mnodeSdb.h"
#include "mnodeShow.h"
#include "mnodeUser.h"
#include "mnodeVgroup.h"
#include "mnodeWrite.h"
#include "mnodePeer.h"
#include "mnodeCluster.h"

int32_t tsAccessSquence = 0;
int64_t        tsDnodeRid = -1;
static void *  tsDnodeSdb = NULL;
static int32_t tsDnodeUpdateSize = 0;
extern void *  tsMnodeSdb;
extern void *  tsVgroupSdb;

static SDnodeEps*tsDnodeEps;
static int32_t   tsDnodeEpsSize;
static pthread_mutex_t tsDnodeEpsMutex;

static int32_t mnodeCreateDnode(char *ep, SMnodeMsg *pMsg);
static int32_t mnodeProcessCreateDnodeMsg(SMnodeMsg *pMsg);
static int32_t mnodeProcessDropDnodeMsg(SMnodeMsg *pMsg);
static int32_t mnodeProcessCfgDnodeMsg(SMnodeMsg *pMsg);
static void    mnodeProcessCfgDnodeMsgRsp(SRpcMsg *rpcMsg) ;
static int32_t mnodeProcessDnodeStatusMsg(SMnodeMsg *pMsg);
static int32_t mnodeGetModuleMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn);
static int32_t mnodeRetrieveModules(SShowObj *pShow, char *data, int32_t rows, void *pConn);
static int32_t mnodeGetConfigMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn);
static int32_t mnodeRetrieveConfigs(SShowObj *pShow, char *data, int32_t rows, void *pConn);
static int32_t mnodeGetVnodeMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn);
static int32_t mnodeRetrieveVnodes(SShowObj *pShow, char *data, int32_t rows, void *pConn);
static int32_t mnodeGetDnodeMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn);
static int32_t mnodeRetrieveDnodes(SShowObj *pShow, char *data, int32_t rows, void *pConn);
static char*   mnodeGetDnodeAlternativeRoleStr(int32_t alternativeRole);
static void    mnodeUpdateDnodeEps();

static char* offlineReason[] = {
  "",
  "status msg timeout",
  "status not received",
  "status reset by mnode",
  "version not match",
  "dnodeId not match",
  "clusterId not match",
  "numOfMnodes not match",
  "balance not match",
  "mnEqualVn not match",
  "offThreshold not match",
  "interval not match",
  "maxTabPerVn not match",
  "maxVgPerDb not match",
  "arbitrator not match",
  "timezone not match",
  "locale not match",
  "charset not match",
  "unknown",
};

static int32_t mnodeDnodeActionDestroy(SSdbRow *pRow) {
  tfree(pRow->pObj);
  return TSDB_CODE_SUCCESS;
}

static int32_t mnodeDnodeActionInsert(SSdbRow *pRow) {
  SDnodeObj *pDnode = pRow->pObj;
  if (pDnode->status != TAOS_DN_STATUS_DROPPING) {
    pDnode->status = TAOS_DN_STATUS_OFFLINE;
    pDnode->lastAccess = tsAccessSquence;
    pDnode->offlineReason = TAOS_DN_OFF_STATUS_NOT_RECEIVED;
  }

  dnodeUpdateEp(pDnode->dnodeId, pDnode->dnodeEp, pDnode->dnodeFqdn, &pDnode->dnodePort);
  mnodeUpdateDnodeEps();

  mInfo("dnode:%d, fqdn:%s ep:%s port:%d, do insert action", pDnode->dnodeId, pDnode->dnodeFqdn, pDnode->dnodeEp, pDnode->dnodePort);
  return TSDB_CODE_SUCCESS;
}

static int32_t mnodeDnodeActionDelete(SSdbRow *pRow) {
  SDnodeObj *pDnode = pRow->pObj;
 
  mnodeDropMnodeLocal(pDnode->dnodeId);
  bnNotify();
  mnodeUpdateDnodeEps();

  mDebug("dnode:%d, all vgroups is dropped from sdb", pDnode->dnodeId);
  return TSDB_CODE_SUCCESS;
}

static int32_t mnodeDnodeActionUpdate(SSdbRow *pRow) {
  SDnodeObj *pNew = pRow->pObj;
  SDnodeObj *pDnode = mnodeGetDnode(pNew->dnodeId);
  if (pDnode != NULL && pNew != pDnode) {
    memcpy(pDnode, pNew, pRow->rowSize);
    free(pNew);
  }
  mnodeDecDnodeRef(pDnode);

  mnodeUpdateDnodeEps();
  return TSDB_CODE_SUCCESS;
}

static int32_t mnodeDnodeActionEncode(SSdbRow *pRow) {
  SDnodeObj *pDnode = pRow->pObj;
  memcpy(pRow->rowData, pDnode, tsDnodeUpdateSize);
  pRow->rowSize = tsDnodeUpdateSize;
  return TSDB_CODE_SUCCESS;
}

static int32_t mnodeDnodeActionDecode(SSdbRow *pRow) {
  SDnodeObj *pDnode = (SDnodeObj *) calloc(1, sizeof(SDnodeObj));
  if (pDnode == NULL) return TSDB_CODE_MND_OUT_OF_MEMORY;

  memcpy(pDnode, pRow->rowData, tsDnodeUpdateSize);
  pRow->pObj = pDnode;
  return TSDB_CODE_SUCCESS;
}

static int32_t mnodeDnodeActionRestored() {
  int32_t numOfRows = sdbGetNumOfRows(tsDnodeSdb);
  if (numOfRows <= 0 && dnodeIsFirstDeploy()) {
    mInfo("dnode first deploy, create dnode:%s", tsLocalEp);
    mnodeCreateDnode(tsLocalEp, NULL);
    SDnodeObj *pDnode = mnodeGetDnodeByEp(tsLocalEp);
    if (pDnode != NULL) {
      mnodeCreateMnode(pDnode->dnodeId, pDnode->dnodeEp, false);
      mnodeDecDnodeRef(pDnode);
    }
  }

  mnodeUpdateDnodeEps();
  return TSDB_CODE_SUCCESS;
}

int32_t mnodeInitDnodes() {
  SDnodeObj tObj;
  tsDnodeUpdateSize = (int8_t *)tObj.updateEnd - (int8_t *)&tObj;
  pthread_mutex_init(&tsDnodeEpsMutex, NULL);

  SSdbTableDesc desc = {
    .id           = SDB_TABLE_DNODE,
    .name         = "dnodes",
    .hashSessions = TSDB_DEFAULT_DNODES_HASH_SIZE,
    .maxRowSize   = tsDnodeUpdateSize,
    .refCountPos  = (int8_t *)(&tObj.refCount) - (int8_t *)&tObj,
    .keyType      = SDB_KEY_AUTO,
    .fpInsert     = mnodeDnodeActionInsert,
    .fpDelete     = mnodeDnodeActionDelete,
    .fpUpdate     = mnodeDnodeActionUpdate,
    .fpEncode     = mnodeDnodeActionEncode,
    .fpDecode     = mnodeDnodeActionDecode,
    .fpDestroy    = mnodeDnodeActionDestroy,
    .fpRestored   = mnodeDnodeActionRestored
  };

  tsDnodeRid = sdbOpenTable(&desc);
  tsDnodeSdb = sdbGetTableByRid(tsDnodeRid);
  if (tsDnodeSdb == NULL) {
    mError("failed to init dnodes data");
    return -1;
  }

  mnodeAddWriteMsgHandle(TSDB_MSG_TYPE_CM_CREATE_DNODE, mnodeProcessCreateDnodeMsg);
  mnodeAddWriteMsgHandle(TSDB_MSG_TYPE_CM_DROP_DNODE, mnodeProcessDropDnodeMsg); 
  mnodeAddWriteMsgHandle(TSDB_MSG_TYPE_CM_CONFIG_DNODE, mnodeProcessCfgDnodeMsg);
  mnodeAddPeerRspHandle(TSDB_MSG_TYPE_MD_CONFIG_DNODE_RSP, mnodeProcessCfgDnodeMsgRsp);
  mnodeAddPeerMsgHandle(TSDB_MSG_TYPE_DM_STATUS, mnodeProcessDnodeStatusMsg);
  mnodeAddShowMetaHandle(TSDB_MGMT_TABLE_MODULE, mnodeGetModuleMeta);
  mnodeAddShowRetrieveHandle(TSDB_MGMT_TABLE_MODULE, mnodeRetrieveModules);
  mnodeAddShowMetaHandle(TSDB_MGMT_TABLE_VARIABLES, mnodeGetConfigMeta);
  mnodeAddShowRetrieveHandle(TSDB_MGMT_TABLE_VARIABLES, mnodeRetrieveConfigs);
  mnodeAddShowMetaHandle(TSDB_MGMT_TABLE_VNODES, mnodeGetVnodeMeta);
  mnodeAddShowRetrieveHandle(TSDB_MGMT_TABLE_VNODES, mnodeRetrieveVnodes);
  mnodeAddShowMetaHandle(TSDB_MGMT_TABLE_DNODE, mnodeGetDnodeMeta);
  mnodeAddShowRetrieveHandle(TSDB_MGMT_TABLE_DNODE, mnodeRetrieveDnodes);
  mnodeAddShowFreeIterHandle(TSDB_MGMT_TABLE_DNODE, mnodeCancelGetNextDnode);
 
  mDebug("table:dnodes table is created");
  return 0;
}

void mnodeCleanupDnodes() {
  sdbCloseTable(tsDnodeRid);
  pthread_mutex_destroy(&tsDnodeEpsMutex);
  free(tsDnodeEps);
  tsDnodeEps = NULL;
  tsDnodeSdb = NULL;
}

void *mnodeGetNextDnode(void *pIter, SDnodeObj **pDnode) { 
  return sdbFetchRow(tsDnodeSdb, pIter, (void **)pDnode); 
}

void mnodeCancelGetNextDnode(void *pIter) {
  sdbFreeIter(tsDnodeSdb, pIter);
}

int32_t mnodeGetDnodesNum() {
  return sdbGetNumOfRows(tsDnodeSdb);
}

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);
  }

  if (cpuCores < 2) cpuCores = 2;
  return cpuCores;
}

int32_t mnodeGetOnlineDnodesNum() {
  SDnodeObj *pDnode = NULL;
  void *     pIter = NULL;
  int32_t    onlineDnodes = 0;

  while (1) {
    pIter = mnodeGetNextDnode(pIter, &pDnode);
    if (pDnode == NULL) break;
    if (pDnode->status != TAOS_DN_STATUS_OFFLINE) onlineDnodes++;
    mnodeDecDnodeRef(pDnode);
  }

  return onlineDnodes;
}

void *mnodeGetDnode(int32_t dnodeId) {
  return sdbGetRow(tsDnodeSdb, &dnodeId);
}

void *mnodeGetDnodeByEp(char *ep) {
  SDnodeObj *pDnode = NULL;
  void *     pIter = NULL;

  while (1) {
    pIter = mnodeGetNextDnode(pIter, &pDnode);
    if (pDnode == NULL) break;
    if (strcmp(ep, pDnode->dnodeEp) == 0) {
      mnodeCancelGetNextDnode(pIter);
      return pDnode;
    }
    mnodeDecDnodeRef(pDnode);
  }


  return NULL;
}

void mnodeIncDnodeRef(SDnodeObj *pDnode) {
  sdbIncRef(tsDnodeSdb, pDnode);
}

void mnodeDecDnodeRef(SDnodeObj *pDnode) {
  sdbDecRef(tsDnodeSdb, pDnode);
}

void mnodeUpdateDnode(SDnodeObj *pDnode) {
  SSdbRow row = {
    .type   = SDB_OPER_GLOBAL,
    .pTable = tsDnodeSdb,
    .pObj   = pDnode
  };

  int32_t code = sdbUpdateRow(&row);
  if (code != TSDB_CODE_SUCCESS && code != TSDB_CODE_MND_ACTION_IN_PROGRESS) {
    mError("dnode:%d, failed update", pDnode->dnodeId);
  }
}

static int32_t mnodeProcessCfgDnodeMsg(SMnodeMsg *pMsg) {
  if (strcmp(pMsg->pUser->user, TSDB_DEFAULT_USER) != 0) {
    mError("failed to cfg dnode, no rights");
    return TSDB_CODE_MND_NO_RIGHTS;
  }
  
  SCfgDnodeMsg *pCmCfgDnode = pMsg->rpcMsg.pCont;
  if (pCmCfgDnode->ep[0] == 0) {
    tstrncpy(pCmCfgDnode->ep, tsLocalEp, TSDB_EP_LEN);
  }

  SDnodeObj *pDnode = mnodeGetDnodeByEp(pCmCfgDnode->ep);
  if (pDnode == NULL) {
    int32_t dnodeId = strtol(pCmCfgDnode->ep, NULL, 10);
    if (dnodeId <= 0 || dnodeId > 65536) {
      mError("failed to cfg dnode, invalid dnodeEp:%s", pCmCfgDnode->ep);
      return TSDB_CODE_MND_DNODE_NOT_EXIST;
    }

    pDnode = mnodeGetDnode(dnodeId);
    if (pDnode == NULL) {
      mError("failed to cfg dnode, invalid dnodeId:%d", dnodeId);
      return TSDB_CODE_MND_DNODE_NOT_EXIST;
    }
  }

  SRpcEpSet epSet = mnodeGetEpSetFromIp(pDnode->dnodeEp);

  if (strncasecmp(pCmCfgDnode->config, "balance", 7) == 0) {
    int32_t vnodeId = 0;
    int32_t dnodeId = 0;
    bool parseOk = taosCheckBalanceCfgOptions(pCmCfgDnode->config + 8, &vnodeId, &dnodeId);
    if (!parseOk) {
      mnodeDecDnodeRef(pDnode);
      return TSDB_CODE_MND_INVALID_DNODE_CFG_OPTION;
    }

    int32_t code = bnAlterDnode(pDnode, vnodeId, dnodeId);
    mnodeDecDnodeRef(pDnode);
    return code;
  } else {
    SCfgDnodeMsg *pMdCfgDnode = rpcMallocCont(sizeof(SCfgDnodeMsg));
    strcpy(pMdCfgDnode->ep, pCmCfgDnode->ep);
    strcpy(pMdCfgDnode->config, pCmCfgDnode->config);

    SRpcMsg rpcMdCfgDnodeMsg = {
      .ahandle = 0,
      .code = 0,
      .msgType = TSDB_MSG_TYPE_MD_CONFIG_DNODE,
      .pCont = pMdCfgDnode,
      .contLen = sizeof(SCfgDnodeMsg)
    };

    mInfo("dnode:%s, is configured by %s", pCmCfgDnode->ep, pMsg->pUser->user);
    dnodeSendMsgToDnode(&epSet, &rpcMdCfgDnodeMsg);
    mnodeDecDnodeRef(pDnode);
    return TSDB_CODE_SUCCESS;
  }
}

static void mnodeProcessCfgDnodeMsgRsp(SRpcMsg *rpcMsg) {
  mInfo("cfg dnode rsp is received");
}

static int32_t mnodeCheckClusterCfgPara(const SClusterCfg *clusterCfg) {
  if (clusterCfg->numOfMnodes != htonl(tsNumOfMnodes)) {
    mError("\"numOfMnodes\"[%d - %d] cfg parameters inconsistent", clusterCfg->numOfMnodes, htonl(tsNumOfMnodes));
    return TAOS_DN_OFF_NUM_OF_MNODES_NOT_MATCH;
  }
  if (clusterCfg->enableBalance != htonl(tsEnableBalance)) {
    mError("\"balance\"[%d - %d] cfg parameters inconsistent", clusterCfg->enableBalance, htonl(tsEnableBalance));
    return TAOS_DN_OFF_ENABLE_BALANCE_NOT_MATCH;
  }
  if (clusterCfg->mnodeEqualVnodeNum != htonl(tsMnodeEqualVnodeNum)) {
    mError("\"mnodeEqualVnodeNum\"[%d - %d] cfg parameters inconsistent", clusterCfg->mnodeEqualVnodeNum,
           htonl(tsMnodeEqualVnodeNum));
    return TAOS_DN_OFF_MN_EQUAL_VN_NOT_MATCH;
  }
  if (clusterCfg->offlineThreshold != htonl(tsOfflineThreshold)) {
    mError("\"offlineThreshold\"[%d - %d] cfg parameters inconsistent", clusterCfg->offlineThreshold,
           htonl(tsOfflineThreshold));
    return TAOS_DN_OFF_OFFLINE_THRESHOLD_NOT_MATCH;
  }
  if (clusterCfg->statusInterval != htonl(tsStatusInterval)) {
    mError("\"statusInterval\"[%d - %d] cfg parameters inconsistent", clusterCfg->statusInterval,
           htonl(tsStatusInterval));
    return TAOS_DN_OFF_STATUS_INTERVAL_NOT_MATCH;
  }
  if (clusterCfg->maxtablesPerVnode != htonl(tsMaxTablePerVnode)) {
    mError("\"maxTablesPerVnode\"[%d - %d] cfg parameters inconsistent", clusterCfg->maxtablesPerVnode,
           htonl(tsMaxTablePerVnode));
    return TAOS_DN_OFF_MAX_TAB_PER_VN_NOT_MATCH;
  }
  if (clusterCfg->maxVgroupsPerDb != htonl(tsMaxVgroupsPerDb)) {
    mError("\"maxVgroupsPerDb\"[%d - %d]  cfg parameters inconsistent", clusterCfg->maxVgroupsPerDb,
           htonl(tsMaxVgroupsPerDb));
    return TAOS_DN_OFF_MAX_VG_PER_DB_NOT_MATCH;
  }
  if (0 != strncasecmp(clusterCfg->arbitrator, tsArbitrator, strlen(tsArbitrator))) {
    mError("\"arbitrator\"[%s - %s]  cfg parameters inconsistent", clusterCfg->arbitrator, tsArbitrator);
    return TAOS_DN_OFF_ARBITRATOR_NOT_MATCH;
  }

  int64_t checkTime = 0;
  char    timestr[32] = "1970-01-01 00:00:00.00";
  (void)taosParseTime(timestr, &checkTime, strlen(timestr), TSDB_TIME_PRECISION_MILLI, 0);
  if ((0 != strncasecmp(clusterCfg->timezone, tsTimezone, strlen(tsTimezone))) &&
      (checkTime != clusterCfg->checkTime)) {
    mError("\"timezone\"[%s - %s] [%" PRId64 " - %" PRId64 "] cfg parameters inconsistent", clusterCfg->timezone,
           tsTimezone, clusterCfg->checkTime, checkTime);
    return TAOS_DN_OFF_TIME_ZONE_NOT_MATCH;
  }

  if (0 != strncasecmp(clusterCfg->locale, tsLocale, strlen(tsLocale))) {
    mError("\"locale\"[%s - %s]  cfg parameters inconsistent", clusterCfg->locale, tsLocale);
    return TAOS_DN_OFF_LOCALE_NOT_MATCH;
  }
  if (0 != strncasecmp(clusterCfg->charset, tsCharset, strlen(tsCharset))) {
    mError("\"charset\"[%s - %s] cfg parameters inconsistent.", clusterCfg->charset, tsCharset);
    return TAOS_DN_OFF_CHARSET_NOT_MATCH;
  }

  return 0;
}

static int32_t mnodeGetDnodeEpsSize() {
  pthread_mutex_lock(&tsDnodeEpsMutex);
  int32_t size = tsDnodeEpsSize;
  pthread_mutex_unlock(&tsDnodeEpsMutex);
  return size;
}

static void mnodeGetDnodeEpsData(SDnodeEps *pEps, int32_t epsSize) {
  pthread_mutex_lock(&tsDnodeEpsMutex);
  if (epsSize == tsDnodeEpsSize) {
    memcpy(pEps, tsDnodeEps, tsDnodeEpsSize);
  }
  pthread_mutex_unlock(&tsDnodeEpsMutex);
}

static void mnodeUpdateDnodeEps() {
  pthread_mutex_lock(&tsDnodeEpsMutex);

  int32_t totalDnodes = mnodeGetDnodesNum();
  tsDnodeEpsSize = sizeof(SDnodeEps) + totalDnodes * sizeof(SDnodeEp);
  free(tsDnodeEps);
  tsDnodeEps = calloc(1, tsDnodeEpsSize);
  tsDnodeEps->dnodeNum = htonl(totalDnodes);

  SDnodeObj *pDnode = NULL;
  void *     pIter = NULL;
  int32_t    dnodesNum = 0;

  while (1) {
    pIter = mnodeGetNextDnode(pIter, &pDnode);
    if (pDnode == NULL) break;
    if (dnodesNum >= totalDnodes) {
      mnodeCancelGetNextDnode(pIter);
      break;
    }

    SDnodeEp *pEp = &tsDnodeEps->dnodeEps[dnodesNum];
    dnodesNum++;
    pEp->dnodeId = htonl(pDnode->dnodeId);
    pEp->dnodePort = htons(pDnode->dnodePort);
    tstrncpy(pEp->dnodeFqdn, pDnode->dnodeFqdn, TSDB_FQDN_LEN);
    mnodeDecDnodeRef(pDnode);
  }

  pthread_mutex_unlock(&tsDnodeEpsMutex);
}

static int32_t mnodeProcessDnodeStatusMsg(SMnodeMsg *pMsg) {
  SDnodeObj *pDnode     = NULL;
  SStatusMsg *pStatus   = pMsg->rpcMsg.pCont;
  pStatus->dnodeId      = htonl(pStatus->dnodeId);
  pStatus->moduleStatus = htonl(pStatus->moduleStatus);
  pStatus->lastReboot   = htonl(pStatus->lastReboot);
  pStatus->numOfCores   = htons(pStatus->numOfCores);

  uint32_t version = htonl(pStatus->version);
  if (version != tsVersion) {
    pDnode = mnodeGetDnodeByEp(pStatus->dnodeEp);
    if (pDnode != NULL && pDnode->status != TAOS_DN_STATUS_READY) {
      pDnode->offlineReason = TAOS_DN_OFF_VERSION_NOT_MATCH;
    }
    mError("dnode:%d, status msg version:%d not equal with cluster:%d", pStatus->dnodeId, version, tsVersion);
    return TSDB_CODE_MND_INVALID_MSG_VERSION;
  }

  if (pStatus->dnodeId == 0) {
    pDnode = mnodeGetDnodeByEp(pStatus->dnodeEp);
    if (pDnode == NULL) {
      mDebug("dnode %s not created", pStatus->dnodeEp);
      return TSDB_CODE_MND_DNODE_NOT_EXIST;
    }
  } else {
    pDnode = mnodeGetDnode(pStatus->dnodeId);
    if (pDnode == NULL) {
      pDnode = mnodeGetDnodeByEp(pStatus->dnodeEp);
      if (pDnode != NULL && pDnode->status != TAOS_DN_STATUS_READY) {
        pDnode->offlineReason = TAOS_DN_OFF_DNODE_ID_NOT_MATCH;
      }
      mError("dnode:%d, %s not exist", pStatus->dnodeId, pStatus->dnodeEp);
      return TSDB_CODE_MND_DNODE_NOT_EXIST;
    }
  }

  pDnode->lastReboot       = pStatus->lastReboot;
  pDnode->numOfCores       = pStatus->numOfCores;
  pDnode->diskAvailable    = pStatus->diskAvailable;
  pDnode->alternativeRole  = pStatus->alternativeRole;
  pDnode->moduleStatus     = pStatus->moduleStatus;

  if (pStatus->dnodeId == 0) {
    mDebug("dnode:%d %s, first access, set clusterId %s", pDnode->dnodeId, pDnode->dnodeEp, mnodeGetClusterId());
  } else {
    if (strncmp(pStatus->clusterId, mnodeGetClusterId(), TSDB_CLUSTER_ID_LEN - 1) != 0) {
      if (pDnode != NULL && pDnode->status != TAOS_DN_STATUS_READY) {
        pDnode->offlineReason = TAOS_DN_OFF_CLUSTER_ID_NOT_MATCH;
      }
      mError("dnode:%d, input clusterId %s not match with exist %s", pDnode->dnodeId, pStatus->clusterId,
             mnodeGetClusterId());
      return TSDB_CODE_MND_INVALID_CLUSTER_ID;
    } else {
      mTrace("dnode:%d, status received, access times %d openVnodes:%d:%d", pDnode->dnodeId, pDnode->lastAccess,
             htons(pStatus->openVnodes), pDnode->openVnodes);
    }
  }

  int32_t openVnodes = htons(pStatus->openVnodes);
  int32_t epsSize = mnodeGetDnodeEpsSize();
  int32_t vgAccessSize = openVnodes * sizeof(SVgroupAccess);
  int32_t contLen = sizeof(SStatusRsp) + vgAccessSize + epsSize;

  SStatusRsp *pRsp = rpcMallocCont(contLen);
  if (pRsp == NULL) {
    mnodeDecDnodeRef(pDnode);
    return TSDB_CODE_MND_OUT_OF_MEMORY;
  }

  pRsp->dnodeCfg.dnodeId = htonl(pDnode->dnodeId);
  pRsp->dnodeCfg.moduleStatus = htonl((int32_t)pDnode->isMgmt);
  pRsp->dnodeCfg.numOfVnodes = htonl(openVnodes);
  tstrncpy(pRsp->dnodeCfg.clusterId, mnodeGetClusterId(), TSDB_CLUSTER_ID_LEN);
  SVgroupAccess *pAccess = (SVgroupAccess *)((char *)pRsp + sizeof(SStatusRsp));
  
  for (int32_t j = 0; j < openVnodes; ++j) {
    SVnodeLoad *pVload = &pStatus->load[j];
    pVload->vgId = htonl(pVload->vgId);
    pVload->cfgVersion = htonl(pVload->cfgVersion);

    SVgObj *pVgroup = mnodeGetVgroup(pVload->vgId);
    if (pVgroup == NULL) {
      SRpcEpSet epSet = mnodeGetEpSetFromIp(pDnode->dnodeEp);
      mInfo("dnode:%d, vgId:%d not exist in mnode, drop it", pDnode->dnodeId, pVload->vgId);
      mnodeSendDropVnodeMsg(pVload->vgId, &epSet, NULL);
    } else {
      mnodeUpdateVgroupStatus(pVgroup, pDnode, pVload);
      pAccess->vgId = htonl(pVload->vgId);
      pAccess->accessState = pVgroup->accessState;
      pAccess++;
      mnodeDecVgroupRef(pVgroup);
    }
  }

  if (pDnode->status == TAOS_DN_STATUS_OFFLINE) {
    // Verify whether the cluster parameters are consistent when status change from offline to ready
    int32_t ret = mnodeCheckClusterCfgPara(&(pStatus->clusterCfg));
    if (0 != ret) {
      pDnode->offlineReason = ret;
      mnodeDecDnodeRef(pDnode);
      rpcFreeCont(pRsp);
      mError("dnode:%d, %s cluster cfg parameters inconsistent, reason:%s", pDnode->dnodeId, pStatus->dnodeEp,
             offlineReason[ret]);
      return TSDB_CODE_MND_CLUSTER_CFG_INCONSISTENT;
    }

    mInfo("dnode:%d, from offline to online", pDnode->dnodeId);
    pDnode->status = TAOS_DN_STATUS_READY;
    pDnode->offlineReason = TAOS_DN_OFF_ONLINE;
    bnCheckModules();
    bnNotify();
  }

  if (openVnodes != pDnode->openVnodes) {
    mnodeCheckUnCreatedVgroup(pDnode, pStatus->load, openVnodes);
  }

  pDnode->lastAccess = tsAccessSquence;

  //this func should be called after sdb replica changed
  mnodeGetMnodeInfos(&pRsp->mnodes);
  
  mnodeDecDnodeRef(pDnode);

  SDnodeEps *pEps = (SDnodeEps *)((char *)pRsp + sizeof(SStatusRsp) + vgAccessSize);
  mnodeGetDnodeEpsData(pEps, epsSize);

  pMsg->rpcRsp.len = contLen;
  pMsg->rpcRsp.rsp =  pRsp;

  return TSDB_CODE_SUCCESS;
}

static int32_t mnodeCreateDnode(char *ep, SMnodeMsg *pMsg) {
  int32_t grantCode = grantCheck(TSDB_GRANT_DNODE);
  if (grantCode != TSDB_CODE_SUCCESS) {
    return grantCode;
  }

  char dnodeEp[TSDB_EP_LEN] = {0};
  tstrncpy(dnodeEp, ep, TSDB_EP_LEN);
  strtrim(dnodeEp);

  char *temp = strchr(dnodeEp, ':');
  if (!temp) {
    int len = strlen(dnodeEp);
    if (dnodeEp[len - 1] == ';') dnodeEp[len - 1] = 0;
    len = strlen(dnodeEp);
    snprintf(dnodeEp + len, TSDB_EP_LEN - len, ":%d", tsServerPort);
  }
  ep = dnodeEp;

  SDnodeObj *pDnode = mnodeGetDnodeByEp(ep);
  if (pDnode != NULL) {
    mnodeDecDnodeRef(pDnode);
    mError("dnode:%d, already exist, %s:%d", pDnode->dnodeId, pDnode->dnodeFqdn, pDnode->dnodePort);
    return TSDB_CODE_MND_DNODE_ALREADY_EXIST;
  }

  pDnode = (SDnodeObj *) calloc(1, sizeof(SDnodeObj));
  pDnode->createdTime = taosGetTimestampMs();
  pDnode->status = TAOS_DN_STATUS_OFFLINE; 
  pDnode->offlineReason = TAOS_DN_OFF_STATUS_NOT_RECEIVED;
  tstrncpy(pDnode->dnodeEp, ep, TSDB_EP_LEN);
  taosGetFqdnPortFromEp(ep, pDnode->dnodeFqdn, &pDnode->dnodePort);

  SSdbRow row = {
    .type    = SDB_OPER_GLOBAL,
    .pTable  = tsDnodeSdb,
    .pObj    = pDnode,
    .rowSize = sizeof(SDnodeObj),
    .pMsg    = pMsg
  };

  int32_t code = sdbInsertRow(&row);
  if (code != TSDB_CODE_SUCCESS && code != TSDB_CODE_MND_ACTION_IN_PROGRESS) {
    int dnodeId = pDnode->dnodeId;
    tfree(pDnode);
    mError("failed to create dnode:%d, reason:%s", dnodeId, tstrerror(code));
  } else {
    mLInfo("dnode:%d is created", pDnode->dnodeId);
  }

  return code;
}

int32_t mnodeDropDnode(SDnodeObj *pDnode, void *pMsg) {
  SSdbRow row = {
    .type   = SDB_OPER_GLOBAL,
    .pTable = tsDnodeSdb,
    .pObj   = pDnode,
    .pMsg   = pMsg
  };

  int32_t code = sdbDeleteRow(&row);
  if (code != TSDB_CODE_SUCCESS && code != TSDB_CODE_MND_ACTION_IN_PROGRESS) {
    mError("dnode:%d, failed to drop from cluster, result:%s", pDnode->dnodeId, tstrerror(code));
  } else {
    mLInfo("dnode:%d, is dropped from cluster", pDnode->dnodeId);
  }

  return code;
}

static int32_t mnodeDropDnodeByEp(char *ep, SMnodeMsg *pMsg) {
  SDnodeObj *pDnode = mnodeGetDnodeByEp(ep);
  if (pDnode == NULL) {
    int32_t dnodeId = (int32_t)strtol(ep, NULL, 10);
    pDnode = mnodeGetDnode(dnodeId);
    if (pDnode == NULL) {
      mError("dnode:%s, is not exist", ep);
      return TSDB_CODE_MND_DNODE_NOT_EXIST;
    }
  }

  if (strcmp(pDnode->dnodeEp, mnodeGetMnodeMasterEp()) == 0) {
    mError("dnode:%d, can't drop dnode:%s which is master", pDnode->dnodeId, ep);
    mnodeDecDnodeRef(pDnode);
    return TSDB_CODE_MND_NO_REMOVE_MASTER;
  }

  mInfo("dnode:%d, start to drop it", pDnode->dnodeId);

  int32_t code = bnDropDnode(pDnode);
  mnodeDecDnodeRef(pDnode);
  return code;
}

static int32_t mnodeProcessCreateDnodeMsg(SMnodeMsg *pMsg) {
  SCreateDnodeMsg *pCreate = pMsg->rpcMsg.pCont;

  if (strcmp(pMsg->pUser->user, TSDB_DEFAULT_USER) != 0) {
    return TSDB_CODE_MND_NO_RIGHTS;
  } else {
    return mnodeCreateDnode(pCreate->ep, pMsg);
  }
}

static int32_t mnodeProcessDropDnodeMsg(SMnodeMsg *pMsg) {
  SDropDnodeMsg *pDrop = pMsg->rpcMsg.pCont;

  if (strcmp(pMsg->pUser->user, TSDB_DEFAULT_USER) != 0) {
    return TSDB_CODE_MND_NO_RIGHTS;
  } else {
    return mnodeDropDnodeByEp(pDrop->ep, pMsg);
  }
}

static int32_t mnodeGetDnodeMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
  SUserObj *pUser = mnodeGetUserFromConn(pConn);
  if (pUser == NULL) return 0;

  if (strcmp(pUser->pAcct->user, TSDB_DEFAULT_USER) != 0) {
    mnodeDecUserRef(pUser);
    return TSDB_CODE_MND_NO_RIGHTS;
  }

  int32_t  cols = 0;
  SSchema *pSchema = pMeta->schema;

  pShow->bytes[cols] = 2;
  pSchema[cols].type = TSDB_DATA_TYPE_SMALLINT;
  strcpy(pSchema[cols].name, "id");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 40 + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "end_point");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 2;
  pSchema[cols].type = TSDB_DATA_TYPE_SMALLINT;
  strcpy(pSchema[cols].name, "vnodes");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 2;
  pSchema[cols].type = TSDB_DATA_TYPE_SMALLINT;
  strcpy(pSchema[cols].name, "cores");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 10 + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "status");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 5 + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "role");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 8;
  pSchema[cols].type = TSDB_DATA_TYPE_TIMESTAMP;
  strcpy(pSchema[cols].name, "create_time");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 24 + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "offline reason");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pMeta->numOfColumns = htons(cols);
  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->numOfRows = mnodeGetDnodesNum();
  pShow->rowSize = pShow->offset[cols - 1] + pShow->bytes[cols - 1];
  pShow->pIter = NULL;

  mnodeDecUserRef(pUser);

  return 0;
}

static int32_t mnodeRetrieveDnodes(SShowObj *pShow, char *data, int32_t rows, void *pConn) {
  int32_t    numOfRows = 0;
  int32_t    cols      = 0;
  SDnodeObj *pDnode   = NULL;
  char      *pWrite;

  while (numOfRows < rows) {
    pShow->pIter = mnodeGetNextDnode(pShow->pIter, &pDnode);
    if (pDnode == NULL) break;

    cols = 0;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    *(int16_t *)pWrite = pDnode->dnodeId;
    cols++;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pDnode->dnodeEp, pShow->bytes[cols]);
    cols++;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    *(int16_t *)pWrite = pDnode->openVnodes;
    cols++;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    *(int16_t *)pWrite = pDnode->numOfCores;
    cols++;
    
    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;  
    char* status = mnodeGetDnodeStatusStr(pDnode->status);
    STR_TO_VARSTR(pWrite, status);
    cols++;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;  
    char* role = mnodeGetDnodeAlternativeRoleStr(pDnode->alternativeRole);
    STR_TO_VARSTR(pWrite, role);
    cols++;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    *(int64_t *)pWrite = pDnode->createdTime;
    cols++;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    STR_TO_VARSTR(pWrite, offlineReason[pDnode->offlineReason]);
    cols++;

     numOfRows++;
    mnodeDecDnodeRef(pDnode);
  }

  mnodeVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);
  pShow->numOfReads += numOfRows;
  return numOfRows;
}

static bool mnodeCheckModuleInDnode(SDnodeObj *pDnode, int32_t moduleType) {
  uint32_t status = pDnode->moduleStatus & (1u << moduleType);
  return status > 0;
}

static int32_t mnodeGetModuleMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
  int32_t cols = 0;

  SUserObj *pUser = mnodeGetUserFromConn(pConn);
  if (pUser == NULL) return 0;

  if (strcmp(pUser->user, TSDB_DEFAULT_USER) != 0)  {
    mnodeDecUserRef(pUser);
    return TSDB_CODE_MND_NO_RIGHTS;
  }

  SSchema *pSchema = pMeta->schema;

  pShow->bytes[cols] = 2;
  pSchema[cols].type = TSDB_DATA_TYPE_SMALLINT;
  strcpy(pSchema[cols].name, "id");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 40 + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "end_point");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 8 + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "module");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 8 + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "status");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pMeta->numOfColumns = htons(cols);
  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->numOfRows = mnodeGetDnodesNum() * TSDB_MOD_MAX;
  pShow->rowSize = pShow->offset[cols - 1] + pShow->bytes[cols - 1];
  pShow->pIter = NULL;
  mnodeDecUserRef(pUser);

  return 0;
}

int32_t mnodeRetrieveModules(SShowObj *pShow, char *data, int32_t rows, void *pConn) {
  int32_t numOfRows = 0;

  char* pWrite;
  char* moduleName[5] = { "MNODE", "HTTP", "MONITOR", "MQTT", "UNKNOWN" };
  int32_t cols;

  while (numOfRows < rows) {
    SDnodeObj *pDnode = NULL;
    pShow->pIter = mnodeGetNextDnode(pShow->pIter, (SDnodeObj **)&pDnode);
    if (pDnode == NULL) break;

    for (int32_t moduleType = 0; moduleType < TSDB_MOD_MAX; ++moduleType) {
      cols = 0;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      *(int16_t *)pWrite = pDnode->dnodeId;
      cols++;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pDnode->dnodeEp, pShow->bytes[cols] - 1);
      cols++;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      STR_WITH_MAXSIZE_TO_VARSTR(pWrite, moduleName[moduleType], pShow->bytes[cols]);
      cols++;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      bool enable = mnodeCheckModuleInDnode(pDnode, moduleType);

      char* v = enable? "enable":"disable";
      STR_TO_VARSTR(pWrite, v);
      cols++;

      numOfRows++;
    }

    mnodeDecDnodeRef(pDnode);
  }

  mnodeVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);
  pShow->numOfReads += numOfRows;
  return numOfRows;
}

static bool mnodeCheckConfigShow(SGlobalCfg *cfg) {
  if (!(cfg->cfgType & TSDB_CFG_CTYPE_B_SHOW))
    return false;
  return true;
}

static int32_t mnodeGetConfigMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
  int32_t cols = 0;

  SUserObj *pUser = mnodeGetUserFromConn(pConn);
  if (pUser == NULL) return 0;

  if (strcmp(pUser->user, TSDB_DEFAULT_USER) != 0)  {
    mnodeDecUserRef(pUser);
    return TSDB_CODE_MND_NO_RIGHTS;
  }

  SSchema *pSchema = pMeta->schema;

  pShow->bytes[cols] = TSDB_CFG_OPTION_LEN + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  tstrncpy(pSchema[cols].name, "name", sizeof(pSchema[cols].name));
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = TSDB_CFG_VALUE_LEN + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  tstrncpy(pSchema[cols].name, "value", sizeof(pSchema[cols].name));
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pMeta->numOfColumns = htons(cols);
  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->numOfRows = 0;
  for (int32_t i = tsGlobalConfigNum - 1; i >= 0; --i) {
    SGlobalCfg *cfg = tsGlobalConfig + i;
    if (!mnodeCheckConfigShow(cfg)) continue;
    pShow->numOfRows++;
  }

  pShow->rowSize = pShow->offset[cols - 1] + pShow->bytes[cols - 1];
  pShow->pIter = NULL;
  mnodeDecUserRef(pUser);

  return 0;
}

static int32_t mnodeRetrieveConfigs(SShowObj *pShow, char *data, int32_t rows, void *pConn) {
  int32_t numOfRows = 0;

  for (int32_t i = tsGlobalConfigNum - 1; i >= 0 && numOfRows < rows; --i) {
    SGlobalCfg *cfg = tsGlobalConfig + i;
    if (!mnodeCheckConfigShow(cfg)) continue;

    char *pWrite;
    int32_t   cols = 0;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    STR_WITH_MAXSIZE_TO_VARSTR(pWrite, cfg->option, TSDB_CFG_OPTION_LEN);

    cols++;
    int32_t t = 0;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    switch (cfg->valType) {
      case TAOS_CFG_VTYPE_INT16:
        t = snprintf(varDataVal(pWrite), TSDB_CFG_VALUE_LEN, "%d", *((int16_t *)cfg->ptr));
        varDataSetLen(pWrite, t);
        numOfRows++;
        break;
      case TAOS_CFG_VTYPE_INT32:
        t = snprintf(varDataVal(pWrite), TSDB_CFG_VALUE_LEN, "%d", *((int32_t *)cfg->ptr));
        varDataSetLen(pWrite, t);
        numOfRows++;
        break;
      case TAOS_CFG_VTYPE_FLOAT:
        t = snprintf(varDataVal(pWrite), TSDB_CFG_VALUE_LEN, "%f", *((float *)cfg->ptr));
        varDataSetLen(pWrite, t);
        numOfRows++;
        break;
      case TAOS_CFG_VTYPE_STRING:
      case TAOS_CFG_VTYPE_IPSTR:
      case TAOS_CFG_VTYPE_DIRECTORY:
        STR_WITH_MAXSIZE_TO_VARSTR(pWrite, cfg->ptr, TSDB_CFG_VALUE_LEN);
        numOfRows++;
        break;
      default:
        break;
    }
  }

  mnodeVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);
  pShow->numOfReads += numOfRows;
  return numOfRows;
}

static int32_t mnodeGetVnodeMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
  int32_t cols = 0;
  SUserObj *pUser = mnodeGetUserFromConn(pConn);
  if (pUser == NULL) return 0;
  
  if (strcmp(pUser->user, TSDB_DEFAULT_USER) != 0)  {
    mnodeDecUserRef(pUser);
    return TSDB_CODE_MND_NO_RIGHTS;
  }

  SSchema *pSchema = pMeta->schema;

  pShow->bytes[cols] = 4;
  pSchema[cols].type = TSDB_DATA_TYPE_INT;
  strcpy(pSchema[cols].name, "vnode");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 12 + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "status");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pMeta->numOfColumns = htons(cols);
  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];

  SDnodeObj *pDnode = NULL;
  if (pShow->payloadLen > 0 ) {
    pDnode = mnodeGetDnodeByEp(pShow->payload);
  } else {
    void *pIter = mnodeGetNextDnode(NULL, (SDnodeObj **)&pDnode);
    mnodeCancelGetNextDnode(pIter);
  }

  if (pDnode != NULL) {
    pShow->numOfRows += pDnode->openVnodes;
    mnodeDecDnodeRef(pDnode);
  }

  pShow->rowSize = pShow->offset[cols - 1] + pShow->bytes[cols - 1];
  pShow->pIter = pDnode;
  mnodeDecUserRef(pUser);

  return 0;
}

static int32_t mnodeRetrieveVnodes(SShowObj *pShow, char *data, int32_t rows, void *pConn) {
  int32_t    numOfRows = 0;
  SDnodeObj *pDnode = NULL;
  char *     pWrite;
  int32_t    cols = 0;

  if (0 == rows) return 0;

  pDnode = (SDnodeObj *)(pShow->pIter);
  if (pDnode != NULL) {
    void *pIter = NULL;
    SVgObj *pVgroup;
    while (1) {
      pIter = mnodeGetNextVgroup(pIter, &pVgroup);
      if (pVgroup == NULL) break;

      for (int32_t i = 0; i < pVgroup->numOfVnodes; ++i) {
        SVnodeGid *pVgid = &pVgroup->vnodeGid[i];
        if (pVgid->pDnode == pDnode) {
          cols = 0;

          pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
          *(uint32_t *)pWrite = pVgroup->vgId;
          cols++;

          pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
          strcpy(pWrite, syncRole[pVgid->role]);
          cols++;
        }
      }

      mnodeDecVgroupRef(pVgroup);
    }
  } else {
    numOfRows = 0;
  }

  mnodeVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);
  pShow->numOfReads += numOfRows;
  return numOfRows;
}

char* mnodeGetDnodeStatusStr(int32_t dnodeStatus) {
  switch (dnodeStatus) {
    case TAOS_DN_STATUS_OFFLINE:   return "offline";
    case TAOS_DN_STATUS_DROPPING:  return "dropping";
    case TAOS_DN_STATUS_BALANCING: return "balancing";
    case TAOS_DN_STATUS_READY:     return "ready";
    default:                       return "undefined";
  }
}

static char* mnodeGetDnodeAlternativeRoleStr(int32_t alternativeRole) {
  switch (alternativeRole) {
    case TAOS_DN_ALTERNATIVE_ROLE_ANY: return "any";
    case TAOS_DN_ALTERNATIVE_ROLE_MNODE: return "mnode";
    case TAOS_DN_ALTERNATIVE_ROLE_VNODE: return "vnode";
    default:return "any";
  }
}