mndProfile.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 "mndProfile.h"
#include "mndConsumer.h"
#include "mndDb.h"
#include "mndMnode.h"
#include "mndShow.h"
#include "mndTopic.h"
#include "mndUser.h"
#include "mndVgroup.h"

#define QUERY_ID_SIZE 20
#define QUERY_OBJ_ID_SIZE 18
#define SUBQUERY_INFO_SIZE 6
#define QUERY_SAVE_SIZE 20

typedef struct {
  int32_t     id;
  char        user[TSDB_USER_LEN];
  char        app[TSDB_APP_NAME_LEN];  // app name that invokes taosc
  int64_t     appStartTimeMs;          // app start time
  int32_t     pid;                     // pid of app that invokes taosc
  uint32_t    ip;
  uint16_t    port;
  int8_t      killed;
  int64_t     loginTimeMs;
  int64_t     lastAccessTimeMs;
  int32_t     queryId;
  int32_t     numOfQueries;
  SQueryDesc *pQueries;
} SConnObj;

static SConnObj *mndCreateConn(SMnode *pMnode, SRpcConnInfo *pInfo, int32_t pid, const char *app, int64_t startTime);
static void      mndFreeConn(SConnObj *pConn);
static SConnObj *mndAcquireConn(SMnode *pMnode, int32_t connId);
static void      mndReleaseConn(SMnode *pMnode, SConnObj *pConn);
static void     *mndGetNextConn(SMnode *pMnode, void *pIter, SConnObj **pConn);
static void      mndCancelGetNextConn(SMnode *pMnode, void *pIter);
static int32_t   mndProcessHeartBeatReq(SMnodeMsg *pReq);
static int32_t   mndProcessConnectReq(SMnodeMsg *pReq);
static int32_t   mndProcessKillQueryReq(SMnodeMsg *pReq);
static int32_t   mndProcessKillConnReq(SMnodeMsg *pReq);
static int32_t   mndGetConnsMeta(SMnodeMsg *pReq, SShowObj *pShow, STableMetaRsp *pMeta);
static int32_t   mndRetrieveConns(SMnodeMsg *pReq, SShowObj *pShow, char *data, int32_t rows);
static int32_t   mndGetQueryMeta(SMnodeMsg *pReq, SShowObj *pShow, STableMetaRsp *pMeta);
static int32_t   mndRetrieveQueries(SMnodeMsg *pReq, SShowObj *pShow, char *data, int32_t rows);
static void      mndCancelGetNextQuery(SMnode *pMnode, void *pIter);

int32_t mndInitProfile(SMnode *pMnode) {
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;

  int32_t connCheckTime = pMnode->cfg.shellActivityTimer * 2;
  pMgmt->cache = taosCacheInit(TSDB_DATA_TYPE_INT, connCheckTime, true, (__cache_free_fn_t)mndFreeConn, "conn");
  if (pMgmt->cache == NULL) {
    terrno = TSDB_CODE_OUT_OF_MEMORY;
    mError("failed to alloc profile cache since %s", terrstr());
    return -1;
  }

  mndSetMsgHandle(pMnode, TDMT_MND_HEARTBEAT, mndProcessHeartBeatReq);
  mndSetMsgHandle(pMnode, TDMT_MND_CONNECT, mndProcessConnectReq);
  mndSetMsgHandle(pMnode, TDMT_MND_KILL_QUERY, mndProcessKillQueryReq);
  mndSetMsgHandle(pMnode, TDMT_MND_KILL_CONN, mndProcessKillConnReq);

  mndAddShowMetaHandle(pMnode, TSDB_MGMT_TABLE_CONNS, mndGetConnsMeta);
  mndAddShowRetrieveHandle(pMnode, TSDB_MGMT_TABLE_CONNS, mndRetrieveConns);
  mndAddShowFreeIterHandle(pMnode, TSDB_MGMT_TABLE_CONNS, mndCancelGetNextConn);
  mndAddShowMetaHandle(pMnode, TSDB_MGMT_TABLE_QUERIES, mndGetQueryMeta);
  mndAddShowRetrieveHandle(pMnode, TSDB_MGMT_TABLE_QUERIES, mndRetrieveQueries);
  mndAddShowFreeIterHandle(pMnode, TSDB_MGMT_TABLE_QUERIES, mndCancelGetNextQuery);

  return 0;
}

void mndCleanupProfile(SMnode *pMnode) {
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;
  if (pMgmt->cache != NULL) {
    taosCacheCleanup(pMgmt->cache);
    pMgmt->cache = NULL;
  }
}

static SConnObj *mndCreateConn(SMnode *pMnode, SRpcConnInfo *pInfo, int32_t pid, const char *app, int64_t startTime) {
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;

  int32_t connId = atomic_add_fetch_32(&pMgmt->connId, 1);
  if (connId == 0) atomic_add_fetch_32(&pMgmt->connId, 1);
  if (startTime == 0) startTime = taosGetTimestampMs();

  SConnObj connObj = {.id = connId,
                      .appStartTimeMs = startTime,
                      .pid = pid,
                      .ip = pInfo->clientIp,
                      .port = pInfo->clientPort,
                      .killed = 0,
                      .loginTimeMs = taosGetTimestampMs(),
                      .lastAccessTimeMs = 0,
                      .queryId = 0,
                      .numOfQueries = 0,
                      .pQueries = NULL};

  connObj.lastAccessTimeMs = connObj.loginTimeMs;
  tstrncpy(connObj.user, pInfo->user, TSDB_USER_LEN);
  tstrncpy(connObj.app, app, TSDB_APP_NAME_LEN);

  int32_t   keepTime = pMnode->cfg.shellActivityTimer * 3;
  SConnObj *pConn = taosCachePut(pMgmt->cache, &connId, sizeof(int32_t), &connObj, sizeof(connObj), keepTime * 1000);
  if (pConn == NULL) {
    terrno = TSDB_CODE_OUT_OF_MEMORY;
    mError("conn:%d, failed to put into cache since %s, user:%s", connId, pInfo->user, terrstr());
    return NULL;
  } else {
    mTrace("conn:%d, is created, data:%p user:%s", pConn->id, pConn, pInfo->user);
    return pConn;
  }
}

static void mndFreeConn(SConnObj *pConn) {
  tfree(pConn->pQueries);
  mTrace("conn:%d, is destroyed, data:%p", pConn->id, pConn);
}

static SConnObj *mndAcquireConn(SMnode *pMnode, int32_t connId) {
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;

  SConnObj *pConn = taosCacheAcquireByKey(pMgmt->cache, &connId, sizeof(int32_t));
  if (pConn == NULL) {
    mDebug("conn:%d, already destroyed", connId);
    return NULL;
  }

  int32_t keepTime = pMnode->cfg.shellActivityTimer * 3;
  pConn->lastAccessTimeMs = keepTime * 1000 + (uint64_t)taosGetTimestampMs();

  mTrace("conn:%d, acquired from cache, data:%p", pConn->id, pConn);
  return pConn;
}

static void mndReleaseConn(SMnode *pMnode, SConnObj *pConn) {
  if (pConn == NULL) return;
  mTrace("conn:%d, released from cache, data:%p", pConn->id, pConn);

  SProfileMgmt *pMgmt = &pMnode->profileMgmt;
  taosCacheRelease(pMgmt->cache, (void **)&pConn, false);
}

static void *mndGetNextConn(SMnode *pMnode, void *pIter, SConnObj **pConn) {
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;

  *pConn = NULL;

  pIter = taosHashIterate(pMgmt->cache->pHashTable, pIter);
  if (pIter == NULL) return NULL;

  SCacheDataNode **pNode = pIter;
  if (pNode == NULL || *pNode == NULL) {
    taosHashCancelIterate(pMgmt->cache->pHashTable, pIter);
    return NULL;
  }

  *pConn = (SConnObj *)((*pNode)->data);
  return pIter;
}

static void mndCancelGetNextConn(SMnode *pMnode, void *pIter) {
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;
  taosHashCancelIterate(pMgmt->cache->pHashTable, pIter);
}

static int32_t mndProcessConnectReq(SMnodeMsg *pReq) {
  SMnode   *pMnode = pReq->pMnode;
  SUserObj *pUser = NULL;
  SDbObj   *pDb = NULL;
  SConnObj *pConn = NULL;
  int32_t   code = -1;

  SConnectReq *pConnReq = pReq->rpcMsg.pCont;
  pConnReq->pid = htonl(pConnReq->pid);
  pConnReq->startTime = htobe64(pConnReq->startTime);

  SRpcConnInfo info = {0};
  if (rpcGetConnInfo(pReq->rpcMsg.handle, &info) != 0) {
    mError("user:%s, failed to login while get connection info since %s", pReq->user, terrstr());
    goto CONN_OVER;
  }

  char ip[30];
  taosIp2String(info.clientIp, ip);

  pUser = mndAcquireUser(pMnode, pReq->user);
  if (pUser == NULL) {
    mError("user:%s, failed to login while acquire user since %s", pReq->user, terrstr());
    goto CONN_OVER;
  }

  if (pConnReq->db[0]) {
    snprintf(pReq->db, TSDB_DB_FNAME_LEN, "%d%s%s", pUser->acctId, TS_PATH_DELIMITER, pConnReq->db);
    pDb = mndAcquireDb(pMnode, pReq->db);
    if (pDb == NULL) {
      terrno = TSDB_CODE_MND_INVALID_DB;
      mError("user:%s, failed to login from %s while use db:%s since %s", pReq->user, ip, pConnReq->db, terrstr());
      goto CONN_OVER;
    }
  }

  pConn = mndCreateConn(pMnode, &info, pConnReq->pid, pConnReq->app, pConnReq->startTime);
  if (pConn == NULL) {
    mError("user:%s, failed to login from %s while create connection since %s", pReq->user, ip, terrstr());
    goto CONN_OVER;
  }

  SConnectRsp *pRsp = rpcMallocCont(sizeof(SConnectRsp));
  if (pRsp == NULL) {
    terrno = TSDB_CODE_OUT_OF_MEMORY;
    mError("user:%s, failed to login from %s while create rsp since %s", pReq->user, ip, terrstr());
    goto CONN_OVER;
  }

  pRsp->acctId = htonl(pUser->acctId);
  pRsp->superUser = pUser->superUser;
  pRsp->clusterId = htobe64(pMnode->clusterId);
  pRsp->connId = htonl(pConn->id);
  mndGetMnodeEpSet(pMnode, &pRsp->epSet);

  pReq->contLen = sizeof(SConnectRsp);
  pReq->pCont = pRsp;

  mDebug("user:%s, login from %s, conn:%d, app:%s", info.user, ip, pConn->id, pConnReq->app);

  code = 0;

CONN_OVER:

  mndReleaseUser(pMnode, pUser);
  mndReleaseDb(pMnode, pDb);
  mndReleaseConn(pMnode, pConn);

  return code;
}

static int32_t mndSaveQueryStreamList(SConnObj *pConn, SHeartBeatReq *pReq) {
  pConn->numOfQueries = 0;
  int32_t numOfQueries = htonl(pReq->numOfQueries);

  if (numOfQueries > 0) {
    if (pConn->pQueries == NULL) {
      pConn->pQueries = calloc(sizeof(SQueryDesc), QUERY_SAVE_SIZE);
    }

    pConn->numOfQueries = MIN(QUERY_SAVE_SIZE, numOfQueries);

    int32_t saveSize = pConn->numOfQueries * sizeof(SQueryDesc);
    if (saveSize > 0 && pConn->pQueries != NULL) {
      memcpy(pConn->pQueries, pReq->pData, saveSize);
    }
  }

  return TSDB_CODE_SUCCESS;
}

static SClientHbRsp* mndMqHbBuildRsp(SMnode* pMnode, SClientHbReq* pReq) {
#if 0
  SClientHbRsp* pRsp = malloc(sizeof(SClientHbRsp));
  if (pRsp == NULL) {
    terrno = TSDB_CODE_OUT_OF_MEMORY;
    return NULL;
  }
  pRsp->connKey = pReq->connKey;
  SMqHbBatchRsp batchRsp;
  batchRsp.batchRsps = taosArrayInit(0, sizeof(SMqHbRsp));
  if (batchRsp.batchRsps == NULL) {
    terrno = TSDB_CODE_OUT_OF_MEMORY;
    return NULL;
  }
  SClientHbKey connKey = pReq->connKey;
  SHashObj* pObj =  pReq->info;
  SKv* pKv = taosHashGet(pObj, "mq-tmp", strlen("mq-tmp") + 1);
  if (pKv == NULL) {
    free(pRsp);
    return NULL;
  }
  SMqHbMsg mqHb;
  taosDecodeSMqMsg(pKv->value, &mqHb);
  /*int64_t clientUid = htonl(pKv->value);*/
  /*if (mqHb.epoch )*/
  int sz = taosArrayGetSize(mqHb.pTopics);
  SMqConsumerObj* pConsumer = mndAcquireConsumer(pMnode, mqHb.consumerId); 
  for (int i = 0; i < sz; i++) {
    SMqHbOneTopicBatchRsp innerBatchRsp;
    innerBatchRsp.rsps = taosArrayInit(sz, sizeof(SMqHbRsp));
    if (innerBatchRsp.rsps == NULL) {
      //TODO
      terrno = TSDB_CODE_OUT_OF_MEMORY;
      return NULL;
    }
    SMqHbTopicInfo* topicInfo = taosArrayGet(mqHb.pTopics, i);
    SMqConsumerTopic* pConsumerTopic = taosHashGet(pConsumer->topicHash, topicInfo->name, strlen(topicInfo->name)+1);
    if (pConsumerTopic->epoch != topicInfo->epoch) {
      //add new vgids into rsp
      int vgSz = taosArrayGetSize(topicInfo->pVgInfo);
      for (int j = 0; j < vgSz; j++) {
        SMqHbRsp innerRsp;
        SMqHbVgInfo* pVgInfo = taosArrayGet(topicInfo->pVgInfo, i);
        SVgObj* pVgObj = mndAcquireVgroup(pMnode, pVgInfo->vgId);
        innerRsp.epSet = mndGetVgroupEpset(pMnode, pVgObj);
        taosArrayPush(innerBatchRsp.rsps, &innerRsp);
      }
    }
    taosArrayPush(batchRsp.batchRsps, &innerBatchRsp);
  }
  int32_t tlen = taosEncodeSMqHbBatchRsp(NULL, &batchRsp);
  void* buf = malloc(tlen);
  if (buf == NULL) {
    //TODO
    return NULL;
  }
  void* abuf = buf;
  taosEncodeSMqHbBatchRsp(&abuf, &batchRsp);
  pRsp->body = buf;
  pRsp->bodyLen = tlen;
  return pRsp;
#endif
  return NULL;
}

static int32_t mndProcessHeartBeatReq(SMnodeMsg *pReq) {
  SMnode *pMnode = pReq->pMnode;
  char *batchReqStr = pReq->rpcMsg.pCont;
  SClientHbBatchReq batchReq = {0};
  tDeserializeSClientHbBatchReq(batchReqStr, &batchReq);
  SArray *pArray = batchReq.reqs;
  int sz = taosArrayGetSize(pArray);

  SClientHbBatchRsp batchRsp = {0};
  batchRsp.rsps = taosArrayInit(0, sizeof(SClientHbRsp));

  for (int i = 0; i < sz; i++) {
    SClientHbReq* pHbReq = taosArrayGet(pArray, i);
    if (pHbReq->connKey.hbType == HEARTBEAT_TYPE_QUERY) {

    } else if (pHbReq->connKey.hbType == HEARTBEAT_TYPE_MQ) {
      SClientHbRsp *pRsp = mndMqHbBuildRsp(pMnode, pHbReq);
      if (pRsp != NULL) {
        taosArrayPush(batchRsp.rsps, pRsp);
        free(pRsp);
      }
    }
  }
  taosArrayDestroyEx(pArray, tFreeClientHbReq);

  int32_t tlen = tSerializeSClientHbBatchRsp(NULL, &batchRsp);
  void* buf = rpcMallocCont(tlen);
  void* abuf = buf;
  tSerializeSClientHbBatchRsp(&abuf, &batchRsp);
  taosArrayDestroy(batchRsp.rsps);
  pReq->contLen = tlen;
  pReq->pCont = buf;
  return 0;

#if 0
  SMnode       *pMnode = pReq->pMnode;
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;

  SHeartBeatReq *pHeartbeat = pReq->rpcMsg.pCont;
  pHeartbeat->connId = htonl(pHeartbeat->connId);
  pHeartbeat->pid = htonl(pHeartbeat->pid);

  SRpcConnInfo info = {0};
  if (rpcGetConnInfo(pReq->rpcMsg.handle, &info) != 0) {
    mError("user:%s, connId:%d failed to process hb since %s", pReq->user, pHeartbeat->connId, terrstr());
    return -1;
  }

  SConnObj *pConn = mndAcquireConn(pMnode, pHeartbeat->connId);
  if (pConn == NULL) {
    pConn = mndCreateConn(pMnode, &info, pHeartbeat->pid, pHeartbeat->app, 0);
    if (pConn == NULL) {
      mError("user:%s, conn:%d is freed and failed to create new since %s", pReq->user, pHeartbeat->connId, terrstr());
      return -1;
    } else {
      mDebug("user:%s, conn:%d is freed and create a new conn:%d", pReq->user, pHeartbeat->connId, pConn->id);
    }
  } else if (pConn->killed) {
    mError("user:%s, conn:%d is already killed", pReq->user, pConn->id);
    terrno = TSDB_CODE_MND_INVALID_CONNECTION;
    return -1;
  } else {
    if (pConn->ip != info.clientIp || pConn->port != info.clientPort /* || strcmp(pConn->user, info.user) != 0 */) {
      char oldIpStr[40];
      char newIpStr[40];
      taosIpPort2String(pConn->ip, pConn->port, oldIpStr);
      taosIpPort2String(info.clientIp, info.clientPort, newIpStr);
      mError("conn:%d, incoming conn user:%s ip:%s, not match exist user:%s ip:%s", pConn->id, info.user, newIpStr,
             pConn->user, oldIpStr);

      if (pMgmt->connId < pConn->id) pMgmt->connId = pConn->id + 1;
      taosCacheRelease(pMgmt->cache, (void **)&pConn, false);
      terrno = TSDB_CODE_MND_INVALID_CONNECTION;
      return -1;
    }
  }

  SHeartBeatRsp *pRsp = rpcMallocCont(sizeof(SHeartBeatRsp));
  if (pRsp == NULL) {
    mndReleaseConn(pMnode, pConn);
    terrno = TSDB_CODE_OUT_OF_MEMORY;
    mError("user:%s, conn:%d failed to process hb while since %s", pReq->user, pHeartbeat->connId, terrstr());
    return -1;
  }

  mndSaveQueryStreamList(pConn, pHeartbeat);
  if (pConn->killed != 0) {
    pRsp->killConnection = 1;
  }

  if (pConn->queryId != 0) {
    pRsp->queryId = htonl(pConn->queryId);
    pConn->queryId = 0;
  }

  pRsp->connId = htonl(pConn->id);
  pRsp->totalDnodes = htonl(1);
  pRsp->onlineDnodes = htonl(1);
  mndGetMnodeEpSet(pMnode, &pRsp->epSet);
  mndReleaseConn(pMnode, pConn);

  pReq->contLen = sizeof(SConnectRsp);
  pReq->pCont = pRsp;
  return 0;
#endif
}

static int32_t mndProcessKillQueryReq(SMnodeMsg *pReq) {
  SMnode       *pMnode = pReq->pMnode;
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;

  SUserObj *pUser = mndAcquireUser(pMnode, pReq->user);
  if (pUser == NULL) return 0;
  if (!pUser->superUser) {
    mndReleaseUser(pMnode, pUser);
    terrno = TSDB_CODE_MND_NO_RIGHTS;
    return -1;
  }
  mndReleaseUser(pMnode, pUser);

  SKillQueryReq *pKill = pReq->rpcMsg.pCont;
  int32_t        connId = htonl(pKill->connId);
  int32_t        queryId = htonl(pKill->queryId);
  mInfo("kill query msg is received, queryId:%d", pKill->queryId);

  SConnObj *pConn = taosCacheAcquireByKey(pMgmt->cache, &connId, sizeof(int32_t));
  if (pConn == NULL) {
    mError("connId:%d, failed to kill queryId:%d, conn not exist", connId, queryId);
    terrno = TSDB_CODE_MND_INVALID_CONN_ID;
    return -1;
  } else {
    mInfo("connId:%d, queryId:%d is killed by user:%s", connId, queryId, pReq->user);
    pConn->queryId = queryId;
    taosCacheRelease(pMgmt->cache, (void **)&pConn, false);
    return 0;
  }
}

static int32_t mndProcessKillConnReq(SMnodeMsg *pReq) {
  SMnode       *pMnode = pReq->pMnode;
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;

  SUserObj *pUser = mndAcquireUser(pMnode, pReq->user);
  if (pUser == NULL) return 0;
  if (!pUser->superUser) {
    mndReleaseUser(pMnode, pUser);
    terrno = TSDB_CODE_MND_NO_RIGHTS;
    return -1;
  }
  mndReleaseUser(pMnode, pUser);

  SKillConnReq *pKill = pReq->rpcMsg.pCont;
  int32_t       connId = htonl(pKill->connId);

  SConnObj *pConn = taosCacheAcquireByKey(pMgmt->cache, &connId, sizeof(int32_t));
  if (pConn == NULL) {
    mError("connId:%d, failed to kill connection, conn not exist", connId);
    terrno = TSDB_CODE_MND_INVALID_CONN_ID;
    return -1;
  } else {
    mInfo("connId:%d, is killed by user:%s", connId, pReq->user);
    pConn->killed = 1;
    taosCacheRelease(pMgmt->cache, (void **)&pConn, false);
    return TSDB_CODE_SUCCESS;
  }
}

static int32_t mndGetConnsMeta(SMnodeMsg *pReq, SShowObj *pShow, STableMetaRsp *pMeta) {
  SMnode       *pMnode = pReq->pMnode;
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;

  SUserObj *pUser = mndAcquireUser(pMnode, pReq->user);
  if (pUser == NULL) return 0;
  if (!pUser->superUser) {
    mndReleaseUser(pMnode, pUser);
    terrno = TSDB_CODE_MND_NO_RIGHTS;
    return -1;
  }
  mndReleaseUser(pMnode, pUser);

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

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

  pShow->bytes[cols] = TSDB_USER_LEN + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "user");
  pSchema[cols].bytes = htonl(pShow->bytes[cols]);
  cols++;

  // app name
  pShow->bytes[cols] = TSDB_APP_NAME_LEN + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "program");
  pSchema[cols].bytes = htonl(pShow->bytes[cols]);
  cols++;

  // app pid
  pShow->bytes[cols] = 4;
  pSchema[cols].type = TSDB_DATA_TYPE_INT;
  strcpy(pSchema[cols].name, "pid");
  pSchema[cols].bytes = htonl(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = TSDB_IPv4ADDR_LEN + 6 + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "ip:port");
  pSchema[cols].bytes = htonl(pShow->bytes[cols]);
  cols++;

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

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

  pMeta->numOfColumns = htonl(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 = taosHashGetSize(pMgmt->cache->pHashTable);
  pShow->rowSize = pShow->offset[cols - 1] + pShow->bytes[cols - 1];
  strcpy(pMeta->tbFname, mndShowStr(pShow->type));

  return 0;
}

static int32_t mndRetrieveConns(SMnodeMsg *pReq, SShowObj *pShow, char *data, int32_t rows) {
  SMnode   *pMnode = pReq->pMnode;
  int32_t   numOfRows = 0;
  SConnObj *pConn = NULL;
  int32_t   cols = 0;
  char     *pWrite;
  char      ipStr[TSDB_IPv4ADDR_LEN + 6];

  while (numOfRows < rows) {
    pShow->pIter = mndGetNextConn(pMnode, pShow->pIter, &pConn);
    if (pConn == NULL) break;

    cols = 0;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    *(int32_t *)pWrite = pConn->id;
    cols++;

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

    // app name
    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pConn->app, pShow->bytes[cols]);
    cols++;

    // app pid
    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    *(int32_t *)pWrite = pConn->pid;
    cols++;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    taosIpPort2String(pConn->ip, pConn->port, ipStr);
    STR_WITH_MAXSIZE_TO_VARSTR(pWrite, ipStr, pShow->bytes[cols]);
    cols++;

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

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    if (pConn->lastAccessTimeMs < pConn->loginTimeMs) pConn->lastAccessTimeMs = pConn->loginTimeMs;
    *(int64_t *)pWrite = pConn->lastAccessTimeMs;
    cols++;

    numOfRows++;
  }

  pShow->numOfReads += numOfRows;

  return numOfRows;
}

static int32_t mndGetQueryMeta(SMnodeMsg *pReq, SShowObj *pShow, STableMetaRsp *pMeta) {
  SMnode       *pMnode = pReq->pMnode;
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;

  SUserObj *pUser = mndAcquireUser(pMnode, pReq->user);
  if (pUser == NULL) return 0;
  if (!pUser->superUser) {
    mndReleaseUser(pMnode, pUser);
    terrno = TSDB_CODE_MND_NO_RIGHTS;
    return -1;
  }
  mndReleaseUser(pMnode, pUser);

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

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

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

  pShow->bytes[cols] = TSDB_USER_LEN + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "user");
  pSchema[cols].bytes = htonl(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = TSDB_IPv4ADDR_LEN + 6 + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "ip:port");
  pSchema[cols].bytes = htonl(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 22 + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "qid");
  pSchema[cols].bytes = htonl(pShow->bytes[cols]);
  cols++;

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

  pShow->bytes[cols] = 8;
  pSchema[cols].type = TSDB_DATA_TYPE_BIGINT;
  strcpy(pSchema[cols].name, "time");
  pSchema[cols].bytes = htonl(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = QUERY_OBJ_ID_SIZE + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "sql_obj_id");
  pSchema[cols].bytes = htonl(pShow->bytes[cols]);
  cols++;

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

  pShow->bytes[cols] = TSDB_EP_LEN + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "ep");
  pSchema[cols].bytes = htonl(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 1;
  pSchema[cols].type = TSDB_DATA_TYPE_BOOL;
  strcpy(pSchema[cols].name, "stable_query");
  pSchema[cols].bytes = htonl(pShow->bytes[cols]);
  cols++;

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

  pShow->bytes[cols] = TSDB_SHOW_SUBQUERY_LEN + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "sub_query_info");
  pSchema[cols].bytes = htonl(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = TSDB_SHOW_SQL_LEN + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "sql");
  pSchema[cols].bytes = htonl(pShow->bytes[cols]);
  cols++;

  pMeta->numOfColumns = htonl(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 = 1000000;
  pShow->rowSize = pShow->offset[cols - 1] + pShow->bytes[cols - 1];
  strcpy(pMeta->tbFname, mndShowStr(pShow->type));

  return 0;
}

static int32_t mndRetrieveQueries(SMnodeMsg *pReq, SShowObj *pShow, char *data, int32_t rows) {
  SMnode   *pMnode = pReq->pMnode;
  int32_t   numOfRows = 0;
  SConnObj *pConn = NULL;
  int32_t   cols = 0;
  char     *pWrite;
  void     *pIter;
  char      str[TSDB_IPv4ADDR_LEN + 6] = {0};

  while (numOfRows < rows) {
    pIter = mndGetNextConn(pMnode, pShow->pIter, &pConn);
    if (pConn == NULL) {
      pShow->pIter = pIter;
      break;
    }

    if (numOfRows + pConn->numOfQueries >= rows) {
      mndCancelGetNextConn(pMnode, pIter);
      break;
    }

    pShow->pIter = pIter;
    for (int32_t i = 0; i < pConn->numOfQueries; ++i) {
      SQueryDesc *pDesc = pConn->pQueries + i;
      cols = 0;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      *(int64_t *)pWrite = htobe64(pDesc->queryId);
      cols++;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      *(int64_t *)pWrite = htobe64(pConn->id);
      cols++;

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

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      snprintf(str, tListLen(str), "%s:%u", taosIpStr(pConn->ip), pConn->port);
      STR_WITH_MAXSIZE_TO_VARSTR(pWrite, str, pShow->bytes[cols]);
      cols++;

      char handleBuf[24] = {0};
      snprintf(handleBuf, tListLen(handleBuf), "%" PRIu64, htobe64(pDesc->qId));
      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;

      STR_WITH_MAXSIZE_TO_VARSTR(pWrite, handleBuf, pShow->bytes[cols]);
      cols++;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      *(int64_t *)pWrite = htobe64(pDesc->stime);
      cols++;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      *(int64_t *)pWrite = htobe64(pDesc->useconds);
      cols++;

      snprintf(str, tListLen(str), "0x%" PRIx64, htobe64(pDesc->sqlObjId));
      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      STR_WITH_MAXSIZE_TO_VARSTR(pWrite, str, pShow->bytes[cols]);
      cols++;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      *(int32_t *)pWrite = htonl(pDesc->pid);
      cols++;

      char epBuf[TSDB_EP_LEN + 1] = {0};
      snprintf(epBuf, tListLen(epBuf), "%s:%u", pDesc->fqdn, pConn->port);
      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      STR_WITH_MAXSIZE_TO_VARSTR(pWrite, epBuf, pShow->bytes[cols]);
      cols++;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      *(bool *)pWrite = pDesc->stableQuery;
      cols++;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      *(int32_t *)pWrite = htonl(pDesc->numOfSub);
      cols++;

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

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

      numOfRows++;
    }
  }

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

static void mndCancelGetNextQuery(SMnode *pMnode, void *pIter) {
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;
  taosHashCancelIterate(pMgmt->cache->pHashTable, pIter);
}