From b85f36bcea67d833b65194333fec446413912ca3 Mon Sep 17 00:00:00 2001
From: Benguang Zhao <bgzhao@taosdata.com>
Date: Thu, 4 Jan 2024 12:00:49 +0800
Subject: [PATCH] enh: allow to drop an empty dnode, no matter online or not

---
 source/dnode/mnode/impl/src/mndDnode.c | 29 +++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/source/dnode/mnode/impl/src/mndDnode.c b/source/dnode/mnode/impl/src/mndDnode.c
index e224aceec2..6585e70533 100644
--- a/source/dnode/mnode/impl/src/mndDnode.c
+++ b/source/dnode/mnode/impl/src/mndDnode.c
@@ -1094,6 +1094,32 @@ _OVER:
   return code;
 }
 
+static bool mndIsEmptyDnode(SMnode *pMnode, int32_t dnodeId) {
+  bool       isEmpty = false;
+  SMnodeObj *pMObj = NULL;
+  SQnodeObj *pQObj = NULL;
+  SSnodeObj *pSObj = NULL;
+
+  pQObj = mndAcquireQnode(pMnode, dnodeId);
+  if (pQObj) goto _OVER;
+
+  pSObj = mndAcquireSnode(pMnode, dnodeId);
+  if (pSObj) goto _OVER;
+
+  pMObj = mndAcquireMnode(pMnode, dnodeId);
+  if (pMObj) goto _OVER;
+
+  int32_t numOfVnodes = mndGetVnodesNum(pMnode, dnodeId);
+  if (numOfVnodes > 0) goto _OVER;
+
+  isEmpty = true;
+_OVER:
+  mndReleaseMnode(pMnode, pMObj);
+  mndReleaseQnode(pMnode, pQObj);
+  mndReleaseSnode(pMnode, pSObj);
+  return isEmpty;
+}
+
 static int32_t mndProcessDropDnodeReq(SRpcMsg *pReq) {
   SMnode       *pMnode = pReq->info.node;
   int32_t       code = -1;
@@ -1155,7 +1181,8 @@ static int32_t mndProcessDropDnodeReq(SRpcMsg *pReq) {
     goto _OVER;
   }
 
-  if (!isonline && !force) {
+  bool isEmpty = mndIsEmptyDnode(pMnode, pDnode->id);
+  if (!isonline && !force && !isEmpty) {
     terrno = TSDB_CODE_DNODE_OFFLINE;
     mError("dnode:%d, failed to drop since %s, vnodes:%d mnode:%d qnode:%d snode:%d", pDnode->id, terrstr(),
            numOfVnodes, pMObj != NULL, pQObj != NULL, pSObj != NULL);