feat: show dnode variables

include/common/tmsg.h

@@ -834,6 +834,14 @@ typedef struct {
 int32_t tSerializeSQnodeListReq(void* buf, int32_t bufLen, SQnodeListReq* pReq);
 int32_t tDeserializeSQnodeListReq(void* buf, int32_t bufLen, SQnodeListReq* pReq);
 
+typedef struct {
+  int32_t rowNum;
+} SDnodeListReq;
+
+int32_t tSerializeSDnodeListReq(void* buf, int32_t bufLen, SDnodeListReq* pReq);
+int32_t tDeserializeSDnodeListReq(void* buf, int32_t bufLen, SDnodeListReq* pReq);
+
+
 typedef struct SQueryNodeAddr {
   int32_t nodeId;  // vgId or qnodeId
   SEpSet  epSet;

include/common/tmsgdef.h

@@ -81,6 +81,7 @@ enum {
   TD_DEF_MSG_TYPE(TDMT_DND_SERVER_STATUS, "server-status", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_DND_NET_TEST, "net-test", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_DND_CONFIG_DNODE, "config-dnode", NULL, NULL)
+  TD_DEF_MSG_TYPE(TDMT_DND_SYSTABLE_RETRIEVE, "dnode-retrieve", NULL, NULL)
 
   TD_NEW_MSG_SEG(TDMT_MND_MSG)
   TD_DEF_MSG_TYPE(TDMT_MND_CONNECT, "connect", NULL, NULL)
@@ -152,7 +153,7 @@ enum {
   TD_DEF_MSG_TYPE(TDMT_MND_HEARTBEAT, "heartbeat", SClientHbBatchReq, SClientHbBatchRsp)
   TD_DEF_MSG_TYPE(TDMT_MND_STATUS, "status", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_MND_SHOW, "show", NULL, NULL)
-  TD_DEF_MSG_TYPE(TDMT_MND_SYSTABLE_RETRIEVE, "retrieve", NULL, NULL)
+  TD_DEF_MSG_TYPE(TDMT_MND_SYSTABLE_RETRIEVE, "mnd-retrieve", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_MND_GRANT, "grant", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_MND_AUTH, "auth", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_MND_APPLY_MSG, "mnode-apply", NULL, NULL)

include/libs/nodes/cmdnodes.h

@@ -36,6 +36,10 @@ extern "C" {
 #define SHOW_CREATE_TB_RESULT_FIELD1_LEN (TSDB_TABLE_NAME_LEN + VARSTR_HEADER_SIZE)
 #define SHOW_CREATE_TB_RESULT_FIELD2_LEN (TSDB_MAX_BINARY_LEN + VARSTR_HEADER_SIZE)
 
+#define SHOW_LOCAL_VARIABLES_RESULT_COLS      2
+#define SHOW_LOCAL_VARIABLES_RESULT_FIELD1_LEN (TSDB_CONFIG_OPTION_LEN + VARSTR_HEADER_SIZE)
+#define SHOW_LOCAL_VARIABLES_RESULT_FIELD2_LEN (TSDB_CONFIG_VALUE_LEN + VARSTR_HEADER_SIZE)
+
 
 #define PRIVILEGE_TYPE_MASK(n) (1 << n)
 

include/util/tconfig.h

@@ -104,6 +104,8 @@ int32_t cfgAddTimezone(SConfig *pCfg, const char *name, const char *defaultVal);
 const char *cfgStypeStr(ECfgSrcType type);
 const char *cfgDtypeStr(ECfgDataType type);
 
+void cfgDumpItemValue(SConfigItem *pItem, char* buf, int32_t bufSize, int32_t* pLen);
+
 void cfgDumpCfg(SConfig *pCfg, bool tsc, bool dump);
 
 int32_t cfgGetApollUrl(const char **envCmd, const char *envFile, char* apolloUrl);

include/util/tdef.h

@@ -443,8 +443,8 @@ enum {
 #define VNODE_HANDLE   -3
 #define BNODE_HANDLE   -4
 
-#define TSDB_CONFIG_OPTION_LEN 16
-#define TSDB_CONIIG_VALUE_LEN  48
+#define TSDB_CONFIG_OPTION_LEN 32
+#define TSDB_CONFIG_VALUE_LEN  64
 #define TSDB_CONFIG_NUMBER     8
 
 #define QUERY_ID_SIZE      20

source/common/src/systable.c

@@ -231,7 +231,13 @@ static const SSysDbTableSchema transSchema[] = {
 
 static const SSysDbTableSchema configSchema[] = {
     {.name = "name", .bytes = TSDB_CONFIG_OPTION_LEN + VARSTR_HEADER_SIZE, .type = TSDB_DATA_TYPE_VARCHAR},
-    {.name = "value", .bytes = TSDB_CONIIG_VALUE_LEN + VARSTR_HEADER_SIZE, .type = TSDB_DATA_TYPE_VARCHAR},
+    {.name = "value", .bytes = TSDB_CONFIG_VALUE_LEN + VARSTR_HEADER_SIZE, .type = TSDB_DATA_TYPE_VARCHAR},
+};
+
+static const SSysDbTableSchema variablesSchema[] = {
+    {.name = "dnode_id", .bytes = 4, .type = TSDB_DATA_TYPE_INT},
+    {.name = "name", .bytes = TSDB_CONFIG_OPTION_LEN + VARSTR_HEADER_SIZE, .type = TSDB_DATA_TYPE_VARCHAR},
+    {.name = "value", .bytes = TSDB_CONFIG_VALUE_LEN + VARSTR_HEADER_SIZE, .type = TSDB_DATA_TYPE_VARCHAR},
 };
 
 static const SSysTableMeta infosMeta[] = {
@@ -253,6 +259,7 @@ static const SSysTableMeta infosMeta[] = {
     {TSDB_INS_TABLE_LICENCES, grantsSchema, tListLen(grantsSchema)},
     {TSDB_INS_TABLE_VGROUPS, vgroupsSchema, tListLen(vgroupsSchema)},
     {TSDB_INS_TABLE_CONFIGS, configSchema, tListLen(configSchema)},
+    {TSDB_INS_TABLE_DNODE_VARIABLES, variablesSchema, tListLen(variablesSchema)},
 };
 
 static const SSysDbTableSchema connectionsSchema[] = {

source/common/src/tmsg.c

@@ -2194,6 +2194,32 @@ int32_t tDeserializeSQnodeListReq(void *buf, int32_t bufLen, SQnodeListReq *pReq
   return 0;
 }
 
+int32_t tSerializeSDnodeListReq(void *buf, int32_t bufLen, SDnodeListReq *pReq) {
+  SEncoder encoder = {0};
+  tEncoderInit(&encoder, buf, bufLen);
+
+  if (tStartEncode(&encoder) < 0) return -1;
+  if (tEncodeI32(&encoder, pReq->rowNum) < 0) return -1;
+  tEndEncode(&encoder);
+
+  int32_t tlen = encoder.pos;
+  tEncoderClear(&encoder);
+  return tlen;
+}
+
+int32_t tDeserializeSDnodeListReq(void *buf, int32_t bufLen, SDnodeListReq *pReq) {
+  SDecoder decoder = {0};
+  tDecoderInit(&decoder, buf, bufLen);
+
+  if (tStartDecode(&decoder) < 0) return -1;
+  if (tDecodeI32(&decoder, &pReq->rowNum) < 0) return -1;
+  tEndDecode(&decoder);
+
+  tDecoderClear(&decoder);
+  return 0;
+}
+
+
 int32_t tSerializeSQnodeListRsp(void *buf, int32_t bufLen, SQnodeListRsp *pRsp) {
   SEncoder encoder = {0};
   tEncoderInit(&encoder, buf, bufLen);

source/dnode/mgmt/mgmt_dnode/inc/dmInt.h

@@ -45,6 +45,7 @@ int32_t dmProcessConfigReq(SDnodeMgmt *pMgmt, SRpcMsg *pMsg);
 int32_t dmProcessAuthRsp(SDnodeMgmt *pMgmt, SRpcMsg *pMsg);
 int32_t dmProcessGrantRsp(SDnodeMgmt *pMgmt, SRpcMsg *pMsg);
 int32_t dmProcessServerRunStatus(SDnodeMgmt *pMgmt, SRpcMsg *pMsg);
+int32_t dmProcessRetrieve(SDnodeMgmt *pMgmt, SRpcMsg *pMsg);
 
 // dmWorker.c
 int32_t dmPutNodeMsgToMgmtQueue(SDnodeMgmt *pMgmt, SRpcMsg *pMsg);

source/dnode/mgmt/mgmt_dnode/src/dmHandle.c

@@ -15,6 +15,10 @@
 
 #define _DEFAULT_SOURCE
 #include "dmInt.h"
+#include "systable.h"
+
+
+extern SConfig *tsCfg;
 
 static void dmUpdateDnodeCfg(SDnodeMgmt *pMgmt, SDnodeCfg *pCfg) {
   if (pMgmt->pData->dnodeId == 0 || pMgmt->pData->clusterId == 0) {
@@ -175,6 +179,130 @@ int32_t dmProcessServerRunStatus(SDnodeMgmt *pMgmt, SRpcMsg *pMsg) {
   return 0;
 }
 
+SSDataBlock* dmBuildVariablesBlock(void) {
+  SSDataBlock* pBlock = taosMemoryCalloc(1, sizeof(SSDataBlock));
+  size_t               size = 0;
+  const SSysTableMeta* pMeta = NULL;
+  getInfosDbMeta(&pMeta, &size);
+
+  int32_t index = 0;
+  for (int32_t i = 0; i < size; ++i) {
+    if (strcmp(pMeta[i].name, TSDB_INS_TABLE_DNODE_VARIABLES) == 0) {
+      index = i;
+      break;
+    }
+  }
+
+  pBlock->pDataBlock = taosArrayInit(pMeta[index].colNum, sizeof(SColumnInfoData));
+
+  for (int32_t i = 0; i < pMeta[index].colNum; ++i) {
+    SColumnInfoData colInfoData = {0};
+    colInfoData.info.colId = i + 1;
+    colInfoData.info.type = pMeta[index].schema[i].type;
+    colInfoData.info.bytes = pMeta[index].schema[i].bytes;
+    taosArrayPush(pBlock->pDataBlock, &colInfoData);
+  }
+
+  pBlock->info.numOfCols = pMeta[index].colNum;
+  pBlock->info.hasVarCol = true;
+
+  return pBlock;
+}
+
+int32_t dmAppendVariablesToBlock(SSDataBlock* pBlock, int32_t dnodeId) {
+  int32_t numOfCfg = taosArrayGetSize(tsCfg->array);
+  int32_t numOfRows = 0;
+  blockDataEnsureCapacity(pBlock, numOfCfg);
+
+  for (int32_t i = 0, c = 0; i < numOfCfg; ++i, c = 0) {
+    SConfigItem *pItem = taosArrayGet(tsCfg->array, i);
+
+    SColumnInfoData *pColInfo = taosArrayGet(pBlock->pDataBlock, c++);
+    colDataAppend(pColInfo, i, (const char *)&dnodeId, false);
+
+    char name[TSDB_CONFIG_OPTION_LEN + VARSTR_HEADER_SIZE] = {0};
+    STR_WITH_MAXSIZE_TO_VARSTR(name, pItem->name, TSDB_CONFIG_OPTION_LEN + VARSTR_HEADER_SIZE);
+    pColInfo = taosArrayGet(pBlock->pDataBlock, c++);
+    colDataAppend(pColInfo, i, name, false);
+    
+    char value[TSDB_CONFIG_VALUE_LEN + VARSTR_HEADER_SIZE] = {0};
+    int32_t valueLen = 0;
+    cfgDumpItemValue(pItem, &value[VARSTR_HEADER_SIZE], TSDB_CONFIG_VALUE_LEN, &valueLen);
+    varDataSetLen(value, valueLen);
+    pColInfo = taosArrayGet(pBlock->pDataBlock, c++);
+    colDataAppend(pColInfo, i, value, false);
+
+    numOfRows++;
+  }
+
+
+  pBlock->info.rows = numOfRows;
+  
+  return TSDB_CODE_SUCCESS;
+}
+
+
+
+int32_t dmProcessRetrieve(SDnodeMgmt *pMgmt, SRpcMsg *pMsg) {
+  int32_t    size = 0;
+  int32_t    rowsRead = 0;
+
+  SRetrieveTableReq retrieveReq = {0};
+  if (tDeserializeSRetrieveTableReq(pMsg->pCont, pMsg->contLen, &retrieveReq) != 0) {
+    terrno = TSDB_CODE_INVALID_MSG;
+    return -1;
+  }
+
+  if (strcasecmp(retrieveReq.tb, TSDB_INS_TABLE_DNODE_VARIABLES)) {
+    terrno = TSDB_CODE_INVALID_MSG;
+    return -1;
+  }
+
+  SSDataBlock* pBlock = dmBuildVariablesBlock();
+
+  dmAppendVariablesToBlock(pBlock, pMgmt->pData->dnodeId);
+
+  size = sizeof(SRetrieveMetaTableRsp) + sizeof(int32_t) + sizeof(SSysTableSchema) * pBlock->info.numOfCols +
+         blockDataGetSize(pBlock) + blockDataGetSerialMetaSize(pBlock->info.numOfCols);
+
+  SRetrieveMetaTableRsp *pRsp = rpcMallocCont(size);
+  if (pRsp == NULL) {
+    terrno = TSDB_CODE_OUT_OF_MEMORY;
+    dError("failed to retrieve data since %s", terrstr());
+    blockDataDestroy(pBlock);
+    return -1;
+  }
+
+  char    *pStart = pRsp->data;
+  *(int32_t *)pStart = htonl(pBlock->info.numOfCols);
+  pStart += sizeof(int32_t);  // number of columns
+
+  for (int32_t i = 0; i < pBlock->info.numOfCols; ++i) {
+    SSysTableSchema *pSchema = (SSysTableSchema *)pStart;
+    SColumnInfoData *pColInfo = taosArrayGet(pBlock->pDataBlock, i);
+    
+    pSchema->bytes = htonl(pColInfo->info.bytes);
+    pSchema->colId = htons(pColInfo->info.colId);
+    pSchema->type = pColInfo->info.type;
+
+    pStart += sizeof(SSysTableSchema);
+  }
+
+  int32_t len = 0;
+  blockCompressEncode(pBlock, pStart, &len, pBlock->info.numOfCols, false);
+
+  pRsp->numOfRows = htonl(pBlock->info.rows);
+  pRsp->precision = TSDB_TIME_PRECISION_MILLI;  // millisecond time precision
+  pRsp->completed = 1;
+  pMsg->info.rsp = pRsp;
+  pMsg->info.rspLen = size;
+  dDebug("dnode variables retrieve completed");
+
+  blockDataDestroy(pBlock);
+  return TSDB_CODE_SUCCESS;
+}
+
+
 SArray *dmGetMsgHandles() {
   int32_t code = -1;
   SArray *pArray = taosArrayInit(16, sizeof(SMgmtHandle));
@@ -191,6 +319,7 @@ SArray *dmGetMsgHandles() {
   if (dmSetMgmtHandle(pArray, TDMT_DND_DROP_BNODE, dmPutNodeMsgToMgmtQueue, 0) == NULL) goto _OVER;
   if (dmSetMgmtHandle(pArray, TDMT_DND_CONFIG_DNODE, dmPutNodeMsgToMgmtQueue, 0) == NULL) goto _OVER;
   if (dmSetMgmtHandle(pArray, TDMT_DND_SERVER_STATUS, dmPutNodeMsgToMgmtQueue, 0) == NULL) goto _OVER;
+  if (dmSetMgmtHandle(pArray, TDMT_DND_SYSTABLE_RETRIEVE, dmPutNodeMsgToMgmtQueue, 0) == NULL) goto _OVER;
 
   // Requests handled by MNODE
   if (dmSetMgmtHandle(pArray, TDMT_MND_GRANT_RSP, dmPutNodeMsgToMgmtQueue, 0) == NULL) goto _OVER;

source/dnode/mgmt/mgmt_dnode/src/dmWorker.c

@@ -141,6 +141,9 @@ static void dmProcessMgmtQueue(SQueueInfo *pInfo, SRpcMsg *pMsg) {
     case TDMT_DND_SERVER_STATUS:
       code = dmProcessServerRunStatus(pMgmt, pMsg);
       break;
+    case TDMT_DND_SYSTABLE_RETRIEVE:
+      code = dmProcessRetrieve(pMgmt, pMsg);
+      break;
     default:
       terrno = TSDB_CODE_MSG_NOT_PROCESSED;
       break;

source/dnode/mgmt/node_mgmt/src/dmTransport.c

@@ -85,6 +85,7 @@ static void dmProcessRpcMsg(SDnode *pDnode, SRpcMsg *pRpc, SEpSet *pEpSet) {
       dmProcessNetTestReq(pDnode, pRpc);
       return;
     case TDMT_MND_SYSTABLE_RETRIEVE_RSP:
+    case TDMT_DND_SYSTABLE_RETRIEVE_RSP:
     case TDMT_VND_FETCH_RSP:
       qWorkerProcessFetchRsp(NULL, NULL, pRpc, 0);
       return;

source/dnode/mnode/impl/src/mndDnode.c

@@ -46,6 +46,7 @@ static SSdbRow *mndDnodeActionDecode(SSdbRaw *pRaw);
 static int32_t  mndDnodeActionInsert(SSdb *pSdb, SDnodeObj *pDnode);
 static int32_t  mndDnodeActionDelete(SSdb *pSdb, SDnodeObj *pDnode);
 static int32_t  mndDnodeActionUpdate(SSdb *pSdb, SDnodeObj *pOld, SDnodeObj *pNew);
+static int32_t  mndProcessDnodeListReq(SRpcMsg *pReq);
 
 static int32_t mndProcessCreateDnodeReq(SRpcMsg *pReq);
 static int32_t mndProcessDropDnodeReq(SRpcMsg *pReq);
@@ -734,28 +735,28 @@ static int32_t mndRetrieveConfigs(SRpcMsg *pReq, SShowObj *pShow, SSDataBlock *p
   int32_t totalRows = 0;
   int32_t numOfRows = 0;
   char   *cfgOpts[TSDB_CONFIG_NUMBER] = {0};
-  char    cfgVals[TSDB_CONFIG_NUMBER][TSDB_CONIIG_VALUE_LEN + 1] = {0};
+  char    cfgVals[TSDB_CONFIG_NUMBER][TSDB_CONFIG_VALUE_LEN + 1] = {0};
   char   *pWrite = NULL;
   int32_t cols = 0;
 
   cfgOpts[totalRows] = "statusInterval";
-  snprintf(cfgVals[totalRows], TSDB_CONIIG_VALUE_LEN, "%d", tsStatusInterval);
+  snprintf(cfgVals[totalRows], TSDB_CONFIG_VALUE_LEN, "%d", tsStatusInterval);
   totalRows++;
 
   cfgOpts[totalRows] = "timezone";
-  snprintf(cfgVals[totalRows], TSDB_CONIIG_VALUE_LEN, "%s", tsTimezoneStr);
+  snprintf(cfgVals[totalRows], TSDB_CONFIG_VALUE_LEN, "%s", tsTimezoneStr);
   totalRows++;
 
   cfgOpts[totalRows] = "locale";
-  snprintf(cfgVals[totalRows], TSDB_CONIIG_VALUE_LEN, "%s", tsLocale);
+  snprintf(cfgVals[totalRows], TSDB_CONFIG_VALUE_LEN, "%s", tsLocale);
   totalRows++;
 
   cfgOpts[totalRows] = "charset";
-  snprintf(cfgVals[totalRows], TSDB_CONIIG_VALUE_LEN, "%s", tsCharset);
+  snprintf(cfgVals[totalRows], TSDB_CONFIG_VALUE_LEN, "%s", tsCharset);
   totalRows++;
 
   char buf[TSDB_CONFIG_OPTION_LEN + VARSTR_HEADER_SIZE] = {0};
-  char bufVal[TSDB_CONIIG_VALUE_LEN + VARSTR_HEADER_SIZE] = {0};
+  char bufVal[TSDB_CONFIG_VALUE_LEN + VARSTR_HEADER_SIZE] = {0};
 
   for (int32_t i = 0; i < totalRows; i++) {
     cols = 0;
@@ -764,7 +765,7 @@ static int32_t mndRetrieveConfigs(SRpcMsg *pReq, SShowObj *pShow, SSDataBlock *p
     SColumnInfoData *pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
     colDataAppend(pColInfo, numOfRows, (const char *)buf, false);
 
-    STR_WITH_MAXSIZE_TO_VARSTR(bufVal, cfgVals[i], TSDB_CONIIG_VALUE_LEN);
+    STR_WITH_MAXSIZE_TO_VARSTR(bufVal, cfgVals[i], TSDB_CONFIG_VALUE_LEN);
     pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
     colDataAppend(pColInfo, numOfRows, (const char *)bufVal, false);
 

source/dnode/mnode/impl/src/mndMain.c

@@ -583,7 +583,7 @@ static int32_t mndCheckMnodeState(SRpcMsg *pMsg) {
 static int32_t mndCheckMsgContent(SRpcMsg *pMsg) {
   if (!IsReq(pMsg)) return 0;
   if (pMsg->contLen != 0 && pMsg->pCont != NULL) return 0;
-
+  
   const STraceId *trace = &pMsg->info.traceId;
   mGError("msg:%p, failed to check msg, cont:%p contLen:%d, app:%p type:%s", pMsg, pMsg->pCont, pMsg->contLen,
          pMsg->info.ahandle, TMSG_INFO(pMsg->msgType));

source/libs/catalog/inc/catalogInt.h

@@ -65,6 +65,7 @@ enum {
 
 typedef enum {
   CTG_TASK_GET_QNODE = 0,
+  CTG_TASK_GET_DNODE,
   CTG_TASK_GET_DB_VGROUP,
   CTG_TASK_GET_DB_CFG,
   CTG_TASK_GET_DB_INFO,
@@ -566,6 +567,7 @@ int32_t ctgGetTbHashVgroupFromCache(SCatalog *pCtg, const SName *pTableName, SVg
 int32_t ctgProcessRspMsg(void* out, int32_t reqType, char* msg, int32_t msgSize, int32_t rspCode, char* target);
 int32_t ctgGetDBVgInfoFromMnode(SCatalog* pCtg, SRequestConnInfo *pConn, SBuildUseDBInput *input, SUseDbOutput *out, SCtgTask* pTask);
 int32_t ctgGetQnodeListFromMnode(SCatalog* pCtg, SRequestConnInfo *pConn, SArray *out, SCtgTask* pTask);
+int32_t ctgGetDnodeListFromMnode(SCatalog* pCtg, SRequestConnInfo *pConn, SArray **out, SCtgTask* pTask);
 int32_t ctgGetDBCfgFromMnode(SCatalog* pCtg, SRequestConnInfo *pConn, const char *dbFName, SDbCfgInfo *out, SCtgTask* pTask);
 int32_t ctgGetIndexInfoFromMnode(SCatalog* pCtg, SRequestConnInfo *pConn, const char *indexName, SIndexInfo *out, SCtgTask* pTask);
 int32_t ctgGetTbIndexFromMnode(SCatalog* pCtg, SRequestConnInfo *pConn, SName *name, STableIndex* out, SCtgTask* pTask);

source/libs/catalog/src/ctgAsync.c

@@ -168,6 +168,21 @@ int32_t ctgInitGetQnodeTask(SCtgJob *pJob, int32_t taskIdx, void* param) {
   return TSDB_CODE_SUCCESS;
 }
 
+int32_t ctgInitGetDnodeTask(SCtgJob *pJob, int32_t taskIdx, void* param) {
+  SCtgTask task = {0};
+
+  task.type = CTG_TASK_GET_DNODE;
+  task.taskId = taskIdx;
+  task.pJob = pJob;
+  task.taskCtx = NULL;
+
+  taosArrayPush(pJob->pTasks, &task);
+
+  qDebug("QID:0x%" PRIx64 " the %d task type %s initialized", pJob->queryId, taskIdx, ctgTaskTypeStr(task.type));
+
+  return TSDB_CODE_SUCCESS;
+}
+
 int32_t ctgInitGetIndexTask(SCtgJob *pJob, int32_t taskIdx, void* param) {
   char *name = (char*)param;
   SCtgTask task = {0};
@@ -511,6 +526,10 @@ int32_t ctgInitJob(SCatalog* pCtg, SRequestConnInfo *pConn, SCtgJob** job, uint6
     CTG_ERR_JRET(ctgInitTask(pJob, CTG_TASK_GET_QNODE, NULL, NULL));
   }
 
+  if (dnodeNum) {
+    CTG_ERR_JRET(ctgInitTask(pJob, CTG_TASK_GET_DNODE, NULL, NULL));
+  }
+
   pJob->refId = taosAddRef(gCtgMgmt.jobPool, pJob);
   if (pJob->refId < 0) {
     ctgError("add job to ref failed, error: %s", tstrerror(terrno));
@@ -633,6 +652,22 @@ int32_t ctgDumpQnodeRes(SCtgTask* pTask) {
   return TSDB_CODE_SUCCESS;
 }
 
+int32_t ctgDumpDnodeRes(SCtgTask* pTask) {
+  SCtgJob* pJob = pTask->pJob;
+  if (NULL == pJob->jobRes.pDnodeList) {
+    pJob->jobRes.pDnodeList = taosArrayInit(1, sizeof(SMetaRes));
+    if (NULL == pJob->jobRes.pDnodeList) {
+      CTG_ERR_RET(TSDB_CODE_OUT_OF_MEMORY);
+    }
+  }
+
+  SMetaRes res = {.code = pTask->code, .pRes = pTask->res};
+  taosArrayPush(pJob->jobRes.pDnodeList, &res);
+
+  return TSDB_CODE_SUCCESS;
+}
+
+
 int32_t ctgDumpDbCfgRes(SCtgTask* pTask) {
   SCtgJob* pJob = pTask->pJob;
   if (NULL == pJob->jobRes.pDbCfg) {
@@ -1038,6 +1073,19 @@ _return:
   CTG_RET(code);
 }
 
+int32_t ctgHandleGetDnodeRsp(SCtgTask* pTask, int32_t reqType, const SDataBuf *pMsg, int32_t rspCode) {
+  int32_t code = 0;
+  CTG_ERR_JRET(ctgProcessRspMsg(&pTask->msgCtx.out, reqType, pMsg->pData, pMsg->len, rspCode, pTask->msgCtx.target));
+
+  TSWAP(pTask->res, pTask->msgCtx.out);
+  
+_return:
+
+  ctgHandleTaskEnd(pTask, code);
+
+  CTG_RET(code);
+}
+
 int32_t ctgHandleGetIndexRsp(SCtgTask* pTask, int32_t reqType, const SDataBuf *pMsg, int32_t rspCode) {
   int32_t code = 0;
   CTG_ERR_JRET(ctgProcessRspMsg(pTask->msgCtx.out, reqType, pMsg->pData, pMsg->len, rspCode, pTask->msgCtx.target));
@@ -1313,6 +1361,15 @@ int32_t ctgLaunchGetQnodeTask(SCtgTask *pTask) {
   return TSDB_CODE_SUCCESS;
 }
 
+int32_t ctgLaunchGetDnodeTask(SCtgTask *pTask) {
+  SCatalog* pCtg = pTask->pJob->pCtg; 
+  SRequestConnInfo* pConn = &pTask->pJob->conn;
+
+  CTG_ERR_RET(ctgGetDnodeListFromMnode(pCtg, pConn, NULL, pTask));
+  return TSDB_CODE_SUCCESS;
+}
+
+
 int32_t ctgLaunchGetDbCfgTask(SCtgTask *pTask) {
   SCatalog* pCtg = pTask->pJob->pCtg; 
   SRequestConnInfo* pConn = &pTask->pJob->conn;
@@ -1464,6 +1521,7 @@ int32_t ctgCloneDbVg(SCtgTask* pTask, void** pRes) {
 
 SCtgAsyncFps gCtgAsyncFps[] = {
   {ctgInitGetQnodeTask,   ctgLaunchGetQnodeTask,   ctgHandleGetQnodeRsp,   ctgDumpQnodeRes,   NULL,               NULL},
+  {ctgInitGetDnodeTask,   ctgLaunchGetDnodeTask,   ctgHandleGetDnodeRsp,   ctgDumpDnodeRes,   NULL,               NULL},
   {ctgInitGetDbVgTask,    ctgLaunchGetDbVgTask,    ctgHandleGetDbVgRsp,    ctgDumpDbVgRes,    ctgCompDbVgTasks,   ctgCloneDbVg},
   {ctgInitGetDbCfgTask,   ctgLaunchGetDbCfgTask,   ctgHandleGetDbCfgRsp,   ctgDumpDbCfgRes,   NULL,               NULL},
   {ctgInitGetDbInfoTask,  ctgLaunchGetDbInfoTask,  ctgHandleGetDbInfoRsp,  ctgDumpDbInfoRes,  NULL,               NULL},

source/libs/catalog/src/ctgRemote.c

@@ -40,6 +40,21 @@ int32_t ctgProcessRspMsg(void* out, int32_t reqType, char* msg, int32_t msgSize,
       qDebug("Got qnode list from mnode, listNum:%d", (int32_t)taosArrayGetSize(out));
       break;
     }
+    case TDMT_MND_DNODE_LIST: {
+      if (TSDB_CODE_SUCCESS != rspCode) {
+        qError("error rsp for dnode list, error:%s", tstrerror(rspCode));
+        CTG_ERR_RET(rspCode);
+      }
+      
+      code = queryProcessMsgRsp[TMSG_INDEX(reqType)](out, msg, msgSize);
+      if (code) {
+        qError("Process dnode list rsp failed, error:%s", tstrerror(rspCode));
+        CTG_ERR_RET(code);
+      }
+      
+      qDebug("Got dnode list from mnode, listNum:%d", (int32_t)taosArrayGetSize(*(SArray**)out));
+      break;
+    }
     case TDMT_MND_USE_DB: {
       if (TSDB_CODE_SUCCESS != rspCode) {
         qError("error rsp for use db, error:%s, dbFName:%s", tstrerror(rspCode), target);
@@ -361,11 +376,7 @@ int32_t ctgGetDnodeListFromMnode(SCatalog* pCtg, SRequestConnInfo *pConn, SArray
   }
 
   if (pTask) {
-    void* pOut = taosArrayInit(4, sizeof(SQueryNodeLoad));
-    if (NULL == pOut) {
-      CTG_ERR_RET(TSDB_CODE_OUT_OF_MEMORY);
-    }
-    CTG_ERR_RET(ctgUpdateMsgCtx(&pTask->msgCtx, reqType, pOut, NULL));
+    CTG_ERR_RET(ctgUpdateMsgCtx(&pTask->msgCtx, reqType, NULL, NULL));
     CTG_RET(ctgAsyncSendMsg(pCtg, pConn, pTask, reqType, msg, msgLen));
   }
   

source/libs/catalog/src/ctgUtil.c

@@ -23,6 +23,8 @@ char *ctgTaskTypeStr(CTG_TASK_TYPE type) {
   switch (type) {
     case CTG_TASK_GET_QNODE:
       return "[get qnode list]";
+    case CTG_TASK_GET_DNODE:
+      return "[get dnode list]";
     case CTG_TASK_GET_DB_VGROUP:
       return "[get db vgroup]";
     case CTG_TASK_GET_DB_CFG:
@@ -349,6 +351,11 @@ void ctgFreeTaskRes(CTG_TASK_TYPE type, void **pRes) {
       *pRes = NULL;
       break;
     }
+    case CTG_TASK_GET_DNODE: {
+      taosArrayDestroy((SArray*)*pRes);
+      *pRes = NULL;
+      break;
+    }
     case CTG_TASK_GET_TB_META: {
       taosMemoryFreeClear(*pRes);
       break;
@@ -413,6 +420,11 @@ void ctgFreeSubTaskRes(CTG_TASK_TYPE type, void **pRes) {
       *pRes = NULL;
       break;
     }
+    case CTG_TASK_GET_DNODE: {
+      taosArrayDestroy((SArray*)*pRes);
+      *pRes = NULL;
+      break;
+    }
     case CTG_TASK_GET_TB_META: {
       taosMemoryFreeClear(*pRes);
       break;

source/libs/command/src/command.c

@@ -18,6 +18,7 @@
 #include "tdatablock.h"
 #include "tglobal.h"
 
+extern SConfig *tsCfg;
 static int32_t getSchemaBytes(const SSchema* pSchema) {
   switch (pSchema->type) {
     case TSDB_DATA_TYPE_BINARY:
@@ -551,7 +552,85 @@ static int32_t execShowCreateSTable(SShowCreateTableStmt* pStmt, SRetrieveTableR
 
 static int32_t execAlterLocal(SAlterLocalStmt* pStmt) { return TSDB_CODE_FAILED; }
 
-static int32_t execShowLocalVariables() { return TSDB_CODE_FAILED; }
+static SSDataBlock* buildLocalVariablesResultDataBlock() {
+  SSDataBlock* pBlock = taosMemoryCalloc(1, sizeof(SSDataBlock));
+  pBlock->info.numOfCols = SHOW_LOCAL_VARIABLES_RESULT_COLS;
+  pBlock->info.hasVarCol = true;
+
+  pBlock->pDataBlock = taosArrayInit(pBlock->info.numOfCols, sizeof(SColumnInfoData));
+
+  SColumnInfoData infoData = {0};
+  infoData.info.type = TSDB_DATA_TYPE_VARCHAR;
+  infoData.info.bytes = SHOW_LOCAL_VARIABLES_RESULT_FIELD1_LEN;
+
+  taosArrayPush(pBlock->pDataBlock, &infoData);
+
+  infoData.info.type = TSDB_DATA_TYPE_VARCHAR;
+  infoData.info.bytes = SHOW_LOCAL_VARIABLES_RESULT_FIELD2_LEN;
+  taosArrayPush(pBlock->pDataBlock, &infoData);
+
+  return pBlock;
+}
+
+
+int32_t setLocalVariablesResultIntoDataBlock(SSDataBlock* pBlock) {
+  int32_t numOfCfg = taosArrayGetSize(tsCfg->array);
+  int32_t numOfRows = 0;
+  blockDataEnsureCapacity(pBlock, numOfCfg);
+
+  for (int32_t i = 0, c = 0; i < numOfCfg; ++i, c = 0) {
+    SConfigItem *pItem = taosArrayGet(tsCfg->array, i);
+
+    char name[TSDB_CONFIG_OPTION_LEN + VARSTR_HEADER_SIZE] = {0};
+    STR_WITH_MAXSIZE_TO_VARSTR(name, pItem->name, TSDB_CONFIG_OPTION_LEN + VARSTR_HEADER_SIZE);
+    SColumnInfoData *pColInfo = taosArrayGet(pBlock->pDataBlock, c++);
+    colDataAppend(pColInfo, i, name, false);
+    
+    char value[TSDB_CONFIG_VALUE_LEN + VARSTR_HEADER_SIZE] = {0};
+    int32_t valueLen = 0;
+    cfgDumpItemValue(pItem, &value[VARSTR_HEADER_SIZE], TSDB_CONFIG_VALUE_LEN, &valueLen);
+    varDataSetLen(value, valueLen);
+    pColInfo = taosArrayGet(pBlock->pDataBlock, c++);
+    colDataAppend(pColInfo, i, value, false);
+
+    numOfRows++;
+  }
+
+
+  pBlock->info.rows = numOfRows;
+  
+  return TSDB_CODE_SUCCESS;
+}
+
+
+static int32_t execShowLocalVariables(SRetrieveTableRsp** pRsp) {
+  SSDataBlock* pBlock = buildLocalVariablesResultDataBlock();
+  int32_t code = setLocalVariablesResultIntoDataBlock(pBlock);
+  if (code) {
+    return code;
+  }
+
+  size_t rspSize = sizeof(SRetrieveTableRsp) + blockGetEncodeSize(pBlock);
+  *pRsp = taosMemoryCalloc(1, rspSize);
+  if (NULL == *pRsp) {
+    return TSDB_CODE_OUT_OF_MEMORY;
+  }
+
+  (*pRsp)->useconds = 0;
+  (*pRsp)->completed = 1;
+  (*pRsp)->precision = 0;
+  (*pRsp)->compressed = 0;
+  (*pRsp)->compLen = 0;
+  (*pRsp)->numOfRows = htonl(pBlock->info.rows);
+  (*pRsp)->numOfCols = htonl(SHOW_LOCAL_VARIABLES_RESULT_COLS);
+
+  int32_t len = 0;
+  blockCompressEncode(pBlock, (*pRsp)->data, &len, SHOW_LOCAL_VARIABLES_RESULT_COLS, false);
+  ASSERT(len == rspSize - sizeof(SRetrieveTableRsp));
+
+  blockDataDestroy(pBlock);
+  return TSDB_CODE_SUCCESS;
+}
 
 int32_t qExecCommand(SNode* pStmt, SRetrieveTableRsp** pRsp) {
   switch (nodeType(pStmt)) {
@@ -568,7 +647,7 @@ int32_t qExecCommand(SNode* pStmt, SRetrieveTableRsp** pRsp) {
     case QUERY_NODE_ALTER_LOCAL_STMT:
       return execAlterLocal((SAlterLocalStmt*)pStmt);
     case QUERY_NODE_SHOW_LOCAL_VARIABLES_STMT:
-      return execShowLocalVariables();
+      return execShowLocalVariables(pRsp);
     default:
       break;
   }

source/libs/executor/src/scanoperator.c

@@ -1541,11 +1541,14 @@ static SSDataBlock* doSysTableScan(SOperatorInfo* pOperator) {
         return NULL;
       }
 
+      int32_t msgType = (strcasecmp(name, TSDB_INS_TABLE_DNODE_VARIABLES) == 0) ? TDMT_DND_SYSTABLE_RETRIEVE : TDMT_MND_SYSTABLE_RETRIEVE;
+
       pMsgSendInfo->param = pOperator;
       pMsgSendInfo->msgInfo.pData = buf1;
       pMsgSendInfo->msgInfo.len = contLen;
-      pMsgSendInfo->msgType = TDMT_MND_SYSTABLE_RETRIEVE;
+      pMsgSendInfo->msgType = msgType;
       pMsgSendInfo->fp = loadSysTableCallback;
+      pMsgSendInfo->requestId = pTaskInfo->id.queryId;
 
       int64_t transporterId = 0;
       int32_t code =
@@ -1580,6 +1583,8 @@ static SSDataBlock* doSysTableScan(SOperatorInfo* pOperator) {
       taosMemoryFree(pRsp);
       if (pInfo->pRes->info.rows > 0) {
         return pInfo->pRes;
+      } else if (pOperator->status == OP_EXEC_DONE) {
+        return NULL;
       }
     }
   }

source/libs/parser/src/parAstParser.c

@@ -137,6 +137,9 @@ static int32_t collectMetaKeyFromRealTableImpl(SCollectMetaKeyCxt* pCxt, SRealTa
     code = reserveTableIndexInCache(pCxt->pParseCxt->acctId, pRealTable->table.dbName, pRealTable->table.tableName,
                                     pCxt->pMetaCache);
   }
+  if (TSDB_CODE_SUCCESS == code && (0 == strcmp(pRealTable->table.tableName, TSDB_INS_TABLE_DNODE_VARIABLES))) {
+    code = reserveDnodeRequiredInCache(pCxt->pMetaCache);
+  }
   return code;
 }
 

source/libs/parser/src/parTranslater.c

@@ -4592,6 +4592,25 @@ static int32_t extractShowCreateTableResultSchema(int32_t* numOfCols, SSchema**
   return TSDB_CODE_SUCCESS;
 }
 
+static int32_t extractShowLocalVariablesResultSchema(int32_t* numOfCols, SSchema** pSchema) {
+  *numOfCols = 2;
+  *pSchema = taosMemoryCalloc((*numOfCols), sizeof(SSchema));
+  if (NULL == (*pSchema)) {
+    return TSDB_CODE_OUT_OF_MEMORY;
+  }
+
+  (*pSchema)[0].type = TSDB_DATA_TYPE_BINARY;
+  (*pSchema)[0].bytes = TSDB_CONFIG_OPTION_LEN;
+  strcpy((*pSchema)[0].name, "name");
+
+  (*pSchema)[1].type = TSDB_DATA_TYPE_BINARY;
+  (*pSchema)[1].bytes = TSDB_CONFIG_VALUE_LEN;
+  strcpy((*pSchema)[1].name, "value");
+
+  return TSDB_CODE_SUCCESS;
+}
+
+
 int32_t extractResultSchema(const SNode* pRoot, int32_t* numOfCols, SSchema** pSchema) {
   if (NULL == pRoot) {
     return TSDB_CODE_SUCCESS;
@@ -4610,6 +4629,8 @@ int32_t extractResultSchema(const SNode* pRoot, int32_t* numOfCols, SSchema** pS
     case QUERY_NODE_SHOW_CREATE_TABLE_STMT:
     case QUERY_NODE_SHOW_CREATE_STABLE_STMT:
       return extractShowCreateTableResultSchema(numOfCols, pSchema);
+    case QUERY_NODE_SHOW_LOCAL_VARIABLES_STMT:
+      return extractShowLocalVariablesResultSchema(numOfCols, pSchema);
     default:
       break;
   }
@@ -5926,12 +5947,12 @@ static int32_t setQuery(STranslateContext* pCxt, SQuery* pQuery) {
     case QUERY_NODE_SHOW_CREATE_DATABASE_STMT:
     case QUERY_NODE_SHOW_CREATE_TABLE_STMT:
     case QUERY_NODE_SHOW_CREATE_STABLE_STMT:
+    case QUERY_NODE_SHOW_LOCAL_VARIABLES_STMT:
       pQuery->execMode = QUERY_EXEC_MODE_LOCAL;
       pQuery->haveResultSet = true;
       break;
     case QUERY_NODE_RESET_QUERY_CACHE_STMT:
     case QUERY_NODE_ALTER_LOCAL_STMT:
-    case QUERY_NODE_SHOW_LOCAL_VARIABLES_STMT:
       pQuery->execMode = QUERY_EXEC_MODE_LOCAL;
       break;
     default:

source/libs/parser/src/parUtil.c

@@ -928,7 +928,12 @@ int32_t reserveDnodeRequiredInCache(SParseMetaCache* pMetaCache) {
 }
 
 int32_t getDnodeListFromCache(SParseMetaCache* pMetaCache, SArray** pDnodes) {
-  *pDnodes = taosArrayDup(pMetaCache->pDnodes);
+  SMetaRes* pRes = taosArrayGet(pMetaCache->pDnodes, 0);
+  if (pRes->code) {
+    return pRes->code;
+  }
+  
+  *pDnodes = taosArrayDup((SArray*)pRes->pRes);
   if (NULL == *pDnodes) {
     return TSDB_CODE_OUT_OF_MEMORY;
   }

source/libs/qcom/src/querymsg.c

@@ -131,8 +131,15 @@ int32_t queryBuildDnodeListMsg(void *input, char **msg, int32_t msgSize, int32_t
     return TSDB_CODE_TSC_INVALID_INPUT;
   }
 
-  *msg = NULL;
-  *msgLen = 0;
+  SDnodeListReq dnodeListReq = {0};
+  dnodeListReq.rowNum = -1;
+
+  int32_t bufLen = tSerializeSDnodeListReq(NULL, 0, &dnodeListReq);
+  void   *pBuf = (*mallcFp)(bufLen);
+  tSerializeSDnodeListReq(pBuf, bufLen, &dnodeListReq);
+
+  *msg = pBuf;
+  *msgLen = bufLen;
 
   return TSDB_CODE_SUCCESS;
 }
@@ -440,7 +447,7 @@ int32_t queryProcessQnodeListRsp(void *output, char *msg, int32_t msgSize) {
   return code;
 }
 
-int32_t queryProcessQnodeListRsp(void *output, char *msg, int32_t msgSize) {
+int32_t queryProcessDnodeListRsp(void *output, char *msg, int32_t msgSize) {
   SDnodeListRsp out = {0};
   int32_t       code = 0;
 
@@ -449,7 +456,6 @@ int32_t queryProcessQnodeListRsp(void *output, char *msg, int32_t msgSize) {
     return code;
   }
 
-  out.dnodeList = (SArray *)output;
   if (tDeserializeSDnodeListRsp(msg, msgSize, &out) != 0) {
     qError("invalid dnode list rsp msg, msgSize:%d", msgSize);
     code = TSDB_CODE_INVALID_MSG;

source/util/src/tconfig.c

@@ -503,6 +503,38 @@ const char *cfgDtypeStr(ECfgDataType type) {
   }
 }
 
+void cfgDumpItemValue(SConfigItem *pItem, char* buf, int32_t bufSize, int32_t* pLen) {
+  int32_t len = 0;
+  switch (pItem->dtype) {
+    case CFG_DTYPE_BOOL:
+      len = snprintf(buf, bufSize, "%u", pItem->bval);
+      break;
+    case CFG_DTYPE_INT32:
+      len = snprintf(buf, bufSize, "%d", pItem->i32);
+      break;
+    case CFG_DTYPE_INT64:
+      len = snprintf(buf, bufSize, "%" PRId64, pItem->i64);
+      break;
+    case CFG_DTYPE_FLOAT:
+      len = snprintf(buf, bufSize, "%f", pItem->fval);
+      break;
+    case CFG_DTYPE_STRING:
+    case CFG_DTYPE_DIR:
+    case CFG_DTYPE_LOCALE:
+    case CFG_DTYPE_CHARSET:
+    case CFG_DTYPE_TIMEZONE:
+    case CFG_DTYPE_NONE:
+      len = snprintf(buf, bufSize, "%s", pItem->str);
+      break;
+  }
+
+  if (len > bufSize) {
+    len = bufSize;
+  }
+
+  *pLen = len;
+}
+
 void cfgDumpCfg(SConfig *pCfg, bool tsc, bool dump) {
   if (dump) {
     printf("                     global config");
@@ -996,4 +1028,4 @@ int32_t cfgGetApollUrl(const char **envCmd, const char *envFile, char* apolloUrl
 
   uInfo("fail get apollo url from cmd env file");
   return -1;
-}
\ No newline at end of file
+}

tests/script/tsim/show/basic.sim

@@ -99,7 +99,7 @@ if $rows != 1 then
 endi
 #sql select * from information_schema.`streams`
 sql select * from information_schema.user_tables
-if $rows != 30 then
+if $rows != 31 then
   return -1
 endi
 #sql select * from information_schema.user_table_distributed
@@ -197,7 +197,7 @@ if $rows != 1 then
 endi
 #sql select * from performance_schema.`streams`
 sql select * from information_schema.user_tables
-if $rows != 30 then
+if $rows != 31 then
   return -1
 endi
 #sql select * from information_schema.user_table_distributed
@@ -227,5 +227,20 @@ endi
 
 sql_error show create stable t0;
 
+sql show variables;
+if $rows != 4 then
+  return -1
+endi
+
+sql show dnode 1 variables;
+if $rows != 114 then
+  return -1
+endi
+
+sql show local variables;
+if $rows != 50 then
+  return -1
+endi
+
 system sh/exec.sh -n dnode1 -s stop -x SIGINT
 system sh/exec.sh -n dnode2 -s stop -x SIGINT