[TD-2255]<enhance>: make db options days and keep error message more clear

src/inc/taoserror.h

@@ -184,6 +184,9 @@ TAOS_DEFINE_ERROR(TSDB_CODE_MND_TOO_MANY_DATABASES,       0, 0x0385, "Too many d
 TAOS_DEFINE_ERROR(TSDB_CODE_MND_DB_IN_DROPPING,           0, 0x0386, "Database not available")
 TAOS_DEFINE_ERROR(TSDB_CODE_MND_VGROUP_NOT_READY,         0, 0x0387, "Database unsynced")
 
+TAOS_DEFINE_ERROR(TSDB_CODE_MND_INVALID_DB_OPTION_DAYS,   0, 0x0390, "Invalid database option: days out of range")
+TAOS_DEFINE_ERROR(TSDB_CODE_MND_INVALID_DB_OPTION_KEEP,   0, 0x0391, "Invalid database option: keep >= keep2 >= keep1 >= days")
+
 // dnode
 TAOS_DEFINE_ERROR(TSDB_CODE_DND_MSG_NOT_PROCESSED,        0, 0x0400, "Message not processed")
 TAOS_DEFINE_ERROR(TSDB_CODE_DND_OUT_OF_MEMORY,            0, 0x0401, "Dnode out of memory")

src/mnode/src/mnodeDb.c

@@ -236,30 +236,28 @@ static int32_t mnodeCheckDbCfg(SDbCfg *pCfg) {
   if (pCfg->daysPerFile < TSDB_MIN_DAYS_PER_FILE || pCfg->daysPerFile > TSDB_MAX_DAYS_PER_FILE) {
     mError("invalid db option daysPerFile:%d valid range: [%d, %d]", pCfg->daysPerFile, TSDB_MIN_DAYS_PER_FILE,
            TSDB_MAX_DAYS_PER_FILE);
-    return TSDB_CODE_MND_INVALID_DB_OPTION;
+    return TSDB_CODE_MND_INVALID_DB_OPTION_DAYS;
   }
 
   if (pCfg->daysToKeep < TSDB_MIN_KEEP || pCfg->daysToKeep > TSDB_MAX_KEEP) {
     mError("invalid db option daysToKeep:%d valid range: [%d, %d]", pCfg->daysToKeep, TSDB_MIN_KEEP, TSDB_MAX_KEEP);
-    return TSDB_CODE_MND_INVALID_DB_OPTION;
+    return TSDB_CODE_MND_INVALID_DB_OPTION_KEEP;
   }
 
   if (pCfg->daysToKeep < pCfg->daysPerFile) {
     mError("invalid db option daysToKeep:%d should larger than daysPerFile:%d", pCfg->daysToKeep, pCfg->daysPerFile);
-    return TSDB_CODE_MND_INVALID_DB_OPTION;
+    return TSDB_CODE_MND_INVALID_DB_OPTION_KEEP;
   }
 
-#if 0
   if (pCfg->daysToKeep2 < TSDB_MIN_KEEP || pCfg->daysToKeep2 > pCfg->daysToKeep) {
     mError("invalid db option daysToKeep2:%d valid range: [%d, %d]", pCfg->daysToKeep, TSDB_MIN_KEEP, pCfg->daysToKeep);
-    return TSDB_CODE_MND_INVALID_DB_OPTION;
+    return TSDB_CODE_MND_INVALID_DB_OPTION_KEEP;
   }
 
   if (pCfg->daysToKeep1 < TSDB_MIN_KEEP || pCfg->daysToKeep1 > pCfg->daysToKeep2) {
     mError("invalid db option daysToKeep1:%d valid range: [%d, %d]", pCfg->daysToKeep1, TSDB_MIN_KEEP, pCfg->daysToKeep2);
-    return TSDB_CODE_MND_INVALID_DB_OPTION;
+    return TSDB_CODE_MND_INVALID_DB_OPTION_KEEP;
   }
-#endif
 
   if (pCfg->maxRowsPerFileBlock < TSDB_MIN_MAX_ROW_FBLOCK || pCfg->maxRowsPerFileBlock > TSDB_MAX_MAX_ROW_FBLOCK) {
     mError("invalid db option maxRowsPerFileBlock:%d valid range: [%d, %d]", pCfg->maxRowsPerFileBlock,