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 "mndDb.h"
#include "mndMnode.h"
#include "mndShow.h"
#include "mndStb.h"
#include "mndUser.h"
#include "tglobal.h"
#include "version.h"

typedef struct {
  uint32_t    id;
  int8_t      connType;
  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;
  uint64_t    killId;
  int32_t     numOfQueries;
  SArray     *pQueries;      //SArray<SQueryDesc>
} SConnObj;

static SConnObj *mndCreateConn(SMnode *pMnode, const char *user, int8_t connType, uint32_t ip, uint16_t port,
                               int32_t pid, const char *app, int64_t startTime);
static void      mndFreeConn(SConnObj *pConn);
static SConnObj *mndAcquireConn(SMnode *pMnode, uint32_t connId);
static void      mndReleaseConn(SMnode *pMnode, SConnObj *pConn);
static void     *mndGetNextConn(SMnode *pMnode, SCacheIter *pIter);
static void      mndCancelGetNextConn(SMnode *pMnode, void *pIter);
static int32_t   mndProcessHeartBeatReq(SNodeMsg *pReq);
static int32_t   mndProcessConnectReq(SNodeMsg *pReq);
static int32_t   mndProcessKillQueryReq(SNodeMsg *pReq);
static int32_t   mndProcessKillConnReq(SNodeMsg *pReq);
static int32_t   mndRetrieveConns(SNodeMsg *pReq, SShowObj *pShow, char *data, int32_t rows);
static int32_t   mndRetrieveQueries(SNodeMsg *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 = tsShellActivityTimer * 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);

//  mndAddShowRetrieveHandle(pMnode, TSDB_MGMT_TABLE_CONNS, mndRetrieveConns);
  mndAddShowFreeIterHandle(pMnode, TSDB_MGMT_TABLE_CONNS, mndCancelGetNextConn);
//  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, const char *user, int8_t connType, uint32_t ip, uint16_t port,
                               int32_t pid, const char *app, int64_t startTime) {
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;

  char connStr[255] = {0};
  int32_t len = snprintf(connStr, sizeof(connStr), "%s%d%d%d%s", user, ip, port, pid, app);
  int32_t connId = mndGenerateUid(connStr, len);
  if (startTime == 0) startTime = taosGetTimestampMs();

  SConnObj connObj = {.id = connId,
                      .connType = connType,
                      .appStartTimeMs = startTime,
                      .pid = pid,
                      .ip = ip,
                      .port = port,
                      .killed = 0,
                      .loginTimeMs = taosGetTimestampMs(),
                      .lastAccessTimeMs = 0,
                      .killId = 0,
                      .numOfQueries = 0,
                      .pQueries = NULL};

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

  int32_t   keepTime = tsShellActivityTimer * 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, user, terrstr());
    return NULL;
  } else {
    mTrace("conn:%u, is created, data:%p user:%s", pConn->id, pConn, user);
    return pConn;
  }
}

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

static SConnObj *mndAcquireConn(SMnode *pMnode, uint32_t connId) {
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;

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

  int32_t keepTime = tsShellActivityTimer * 3;
  pConn->lastAccessTimeMs = keepTime * 1000 + (uint64_t)taosGetTimestampMs();

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

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

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

void *mndGetNextConn(SMnode *pMnode, SCacheIter *pIter) {
  SConnObj *pConn = NULL;
  bool      hasNext = taosCacheIterNext(pIter);
  if (hasNext) {
    size_t dataLen = 0;
    pConn = taosCacheIterGetData(pIter, &dataLen);
  } else {
    taosCacheDestroyIter(pIter);
  }

  return pConn;
}

static void mndCancelGetNextConn(SMnode *pMnode, void *pIter) {
  if (pIter != NULL) {
    taosCacheDestroyIter(pIter);
  }
}

static int32_t mndProcessConnectReq(SNodeMsg *pReq) {
  SMnode     *pMnode = pReq->pNode;
  SUserObj   *pUser = NULL;
  SDbObj     *pDb = NULL;
  SConnObj   *pConn = NULL;
  int32_t     code = -1;
  SConnectReq connReq = {0};
  char        ip[30] = {0};

  if (tDeserializeSConnectReq(pReq->rpcMsg.pCont, pReq->rpcMsg.contLen, &connReq) != 0) {
    terrno = TSDB_CODE_INVALID_MSG;
    goto CONN_OVER;
  }

  taosIp2String(pReq->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 (connReq.db[0]) {
    char db[TSDB_DB_FNAME_LEN];
    snprintf(db, TSDB_DB_FNAME_LEN, "%d%s%s", pUser->acctId, TS_PATH_DELIMITER, connReq.db);
    pDb = mndAcquireDb(pMnode, 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, connReq.db, terrstr());
      goto CONN_OVER;
    }
  }

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

  mndAcquireConn(pMnode, pConn->id);

  SConnectRsp connectRsp = {0};
  connectRsp.acctId = pUser->acctId;
  connectRsp.superUser = pUser->superUser;
  connectRsp.clusterId = pMnode->clusterId;
  connectRsp.connId = pConn->id;
  connectRsp.connType = connReq.connType;

  snprintf(connectRsp.sVersion, sizeof(connectRsp.sVersion), "ver:%s\nbuild:%s\ngitinfo:%s", version, buildinfo,
           gitinfo);
  mndGetMnodeEpSet(pMnode, &connectRsp.epSet);

  int32_t contLen = tSerializeSConnectRsp(NULL, 0, &connectRsp);
  if (contLen < 0) goto CONN_OVER;
  void *pRsp = rpcMallocCont(contLen);
  if (pRsp == NULL) goto CONN_OVER;
  tSerializeSConnectRsp(pRsp, contLen, &connectRsp);

  pReq->rspLen = contLen;
  pReq->pRsp = pRsp;

  mDebug("user:%s, login from %s:%d, conn:%u, app:%s", pReq->user, ip, pConn->port, pConn->id, connReq.app);

  code = 0;

CONN_OVER:

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

  return code;
}

static int32_t mndSaveQueryList(SConnObj *pConn, SQueryHbReqBasic *pBasic) {
  taosArrayDestroyEx(pConn->pQueries, tFreeClientHbQueryDesc);

  pConn->pQueries = pBasic->queryDesc;
  pBasic->queryDesc = NULL;
  
  pConn->numOfQueries =  pBasic->queryDesc ? taosArrayGetSize(pBasic->queryDesc) : 0;

  return TSDB_CODE_SUCCESS;
}

static SClientHbRsp *mndMqHbBuildRsp(SMnode *pMnode, SClientHbReq *pReq) {
#if 0
  SClientHbRsp* pRsp = taosMemoryMalloc(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) {
    taosMemoryFree(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 = taosMemoryMalloc(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 mndProcessQueryHeartBeat(SMnode *pMnode, SRpcMsg *pMsg, SClientHbReq *pHbReq, SClientHbBatchRsp *pBatchRsp) {
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;
  SClientHbRsp hbRsp = {.connKey = pHbReq->connKey, .status = 0, .info = NULL, .query = NULL};

  if (pHbReq->query) {
    SQueryHbReqBasic *pBasic = pHbReq->query;

    SRpcConnInfo connInfo = {0};
    rpcGetConnInfo(pMsg->handle, &connInfo);

    SConnObj *pConn = mndAcquireConn(pMnode, pBasic->connId);
    if (pConn == NULL) {    
      pConn = mndCreateConn(pMnode, connInfo.user, CONN_TYPE__QUERY, connInfo.clientIp, connInfo.clientPort, pBasic->pid, pBasic->app, 0);
      if (pConn == NULL) {
        mError("user:%s, conn:%u is freed and failed to create new since %s", connInfo.user, pBasic->connId, terrstr());
        return -1;
      } else {
        mDebug("user:%s, conn:%u is freed and create a new conn:%u", connInfo.user, pBasic->connId, pConn->id);
      }
    } else if (pConn->killed) {
      mError("user:%s, conn:%u is already killed", connInfo.user, pConn->id);
      mndReleaseConn(pMnode, pConn);      
      terrno = TSDB_CODE_MND_INVALID_CONNECTION;
      return -1;
    }

    SQueryHbRspBasic *rspBasic = taosMemoryCalloc(1, sizeof(SQueryHbRspBasic));
    if (rspBasic == NULL) {
      mndReleaseConn(pMnode, pConn);
      terrno = TSDB_CODE_OUT_OF_MEMORY;
      mError("user:%s, conn:%u failed to process hb while since %s", pConn->user, pBasic->connId, terrstr());
      return -1;
    }

    mndSaveQueryList(pConn, pBasic);
    if (pConn->killed != 0) {
      rspBasic->killConnection = 1;
    }

    if (pConn->killId != 0) {
      rspBasic->killRid = pConn->killId;
      pConn->killId = 0;
    }

    rspBasic->connId = pConn->id;
    rspBasic->totalDnodes = 1;  //TODO
    rspBasic->onlineDnodes = 1; //TODO
    mndGetMnodeEpSet(pMnode, &rspBasic->epSet);
    mndReleaseConn(pMnode, pConn);

    hbRsp.query = rspBasic;
  }

  int32_t kvNum = taosHashGetSize(pHbReq->info);
  if (NULL == pHbReq->info || kvNum <= 0) {
    taosArrayPush(pBatchRsp->rsps, &hbRsp);  
    return TSDB_CODE_SUCCESS;
  }

  hbRsp.info = taosArrayInit(kvNum, sizeof(SKv));
  if (NULL == hbRsp.info) {
    mError("taosArrayInit %d rsp kv failed", kvNum);
    terrno = TSDB_CODE_OUT_OF_MEMORY;
    return -1;
  }

  void *pIter = taosHashIterate(pHbReq->info, NULL);
  while (pIter != NULL) {
    SKv *kv = pIter;

    switch (kv->key) {
      case HEARTBEAT_KEY_DBINFO: {
        void   *rspMsg = NULL;
        int32_t rspLen = 0;
        mndValidateDbInfo(pMnode, kv->value, kv->valueLen / sizeof(SDbVgVersion), &rspMsg, &rspLen);
        if (rspMsg && rspLen > 0) {
          SKv kv1 = {.key = HEARTBEAT_KEY_DBINFO, .valueLen = rspLen, .value = rspMsg};
          taosArrayPush(hbRsp.info, &kv1);
        }
        break;
      }
      case HEARTBEAT_KEY_STBINFO: {
        void   *rspMsg = NULL;
        int32_t rspLen = 0;
        mndValidateStbInfo(pMnode, kv->value, kv->valueLen / sizeof(SSTableMetaVersion), &rspMsg, &rspLen);
        if (rspMsg && rspLen > 0) {
          SKv kv1 = {.key = HEARTBEAT_KEY_STBINFO, .valueLen = rspLen, .value = rspMsg};
          taosArrayPush(hbRsp.info, &kv1);
        }
        break;
      }
      default:
        mError("invalid kv key:%d", kv->key);
        hbRsp.status = TSDB_CODE_MND_APP_ERROR;
        break;
    }

    pIter = taosHashIterate(pHbReq->info, pIter);
  }

  taosArrayPush(pBatchRsp->rsps, &hbRsp);

  return TSDB_CODE_SUCCESS;
}

static int32_t mndProcessHeartBeatReq(SNodeMsg *pReq) {
  SMnode *pMnode = pReq->pNode;

  SClientHbBatchReq batchReq = {0};
  if (tDeserializeSClientHbBatchReq(pReq->rpcMsg.pCont, pReq->rpcMsg.contLen, &batchReq) != 0) {
    terrno = TSDB_CODE_INVALID_MSG;
    return -1;
  }

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

  int32_t sz = taosArrayGetSize(batchReq.reqs);
  for (int i = 0; i < sz; i++) {
    SClientHbReq *pHbReq = taosArrayGet(batchReq.reqs, i);
    if (pHbReq->connKey.connType == CONN_TYPE__QUERY) {
      mndProcessQueryHeartBeat(pMnode, &pReq->rpcMsg, pHbReq, &batchRsp);
    } else if (pHbReq->connKey.connType == CONN_TYPE__TMQ) {
      SClientHbRsp *pRsp = mndMqHbBuildRsp(pMnode, pHbReq);
      if (pRsp != NULL) {
        taosArrayPush(batchRsp.rsps, pRsp);
        taosMemoryFree(pRsp);
      }
    }
  }
  taosArrayDestroyEx(batchReq.reqs, tFreeClientHbReq);

  int32_t tlen = tSerializeSClientHbBatchRsp(NULL, 0, &batchRsp);
  void   *buf = rpcMallocCont(tlen);
  tSerializeSClientHbBatchRsp(buf, tlen, &batchRsp);

  int32_t rspNum = (int32_t)taosArrayGetSize(batchRsp.rsps);
  for (int32_t i = 0; i < rspNum; ++i) {
    SClientHbRsp *rsp = taosArrayGet(batchRsp.rsps, i);
    int32_t       kvNum = (rsp->info) ? taosArrayGetSize(rsp->info) : 0;
    for (int32_t n = 0; n < kvNum; ++n) {
      SKv *kv = taosArrayGet(rsp->info, n);
      taosMemoryFreeClear(kv->value);
    }
    taosArrayDestroy(rsp->info);
  }

  taosArrayDestroy(batchRsp.rsps);
  pReq->rspLen = tlen;
  pReq->pRsp = buf;

  return 0;
}

static int32_t mndProcessKillQueryReq(SNodeMsg *pReq) {
  SMnode       *pMnode = pReq->pNode;
  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 killReq = {0};
  if (tDeserializeSKillQueryReq(pReq->rpcMsg.pCont, pReq->rpcMsg.contLen, &killReq) != 0) {
    terrno = TSDB_CODE_INVALID_MSG;
    return -1;
  }

  mInfo("kill query msg is received, queryId:%d", killReq.queryId);

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

static int32_t mndProcessKillConnReq(SNodeMsg *pReq) {
  SMnode       *pMnode = pReq->pNode;
  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 killReq = {0};
  if (tDeserializeSKillConnReq(pReq->rpcMsg.pCont, pReq->rpcMsg.contLen, &killReq) != 0) {
    terrno = TSDB_CODE_INVALID_MSG;
    return -1;
  }

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

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

  if (pShow->pIter == NULL) {
    SProfileMgmt *pMgmt = &pMnode->profileMgmt;
    pShow->pIter = taosCacheCreateIter(pMgmt->cache);
  }

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

    cols = 0;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    *(uint32_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->numOfRows += numOfRows;

  return numOfRows;
}

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

  if (pShow->pIter == NULL) {
    SProfileMgmt *pMgmt = &pMnode->profileMgmt;
    pShow->pIter = taosCacheCreateIter(pMgmt->cache);
  }

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

    if (numOfRows + pConn->numOfQueries >= rows) {
      taosCacheDestroyIter(pShow->pIter);
      pShow->pIter = NULL;
      break;
    }

    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++;
    }
  }

  pShow->numOfRows += numOfRows;
#endif  
  return numOfRows;
}

static void mndCancelGetNextQuery(SMnode *pMnode, void *pIter) {
  if (pIter != NULL) {
    taosCacheDestroyIter(pIter);
  }
}

int32_t mndGetNumOfConnections(SMnode *pMnode) {
  SProfileMgmt *pMgmt = &pMnode->profileMgmt;
  return taosCacheGetNumOfObj(pMgmt->cache);
}