From 66f4ee9a41315ecdcb44e522f5a68cc28ef84c90 Mon Sep 17 00:00:00 2001
From: Shengliang Guan <slguan@taosdata.com>
Date: Wed, 7 Dec 2022 21:57:49 +0800
Subject: [PATCH] enh: alter db replica return quickly, operation executed
 asynchronously

---
 source/dnode/mnode/impl/src/mndDb.c       |  8 +++++++-
 tests/script/tsim/db/alter_replica_13.sim | 19 +++++++++++++++++++
 tests/script/tsim/db/alter_replica_31.sim | 20 ++++++++++++++++++++
 3 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/source/dnode/mnode/impl/src/mndDb.c b/source/dnode/mnode/impl/src/mndDb.c
index 5fa86dffe2..43155124c1 100644
--- a/source/dnode/mnode/impl/src/mndDb.c
+++ b/source/dnode/mnode/impl/src/mndDb.c
@@ -825,7 +825,13 @@ static int32_t mndProcessAlterDbReq(SRpcMsg *pReq) {
   dbObj.cfgVersion++;
   dbObj.updateTime = taosGetTimestampMs();
   code = mndAlterDb(pMnode, pReq, pDb, &dbObj);
-  if (code == 0) code = TSDB_CODE_ACTION_IN_PROGRESS;
+
+  if (dbObj.cfg.replications != pDb->cfg.replications) {
+    // return quickly, operation executed asynchronously
+    mInfo("db:%s, alter db replica from %d to %d", pDb->name, pDb->cfg.replications, dbObj.cfg.replications);
+  } else {
+    if (code == 0) code = TSDB_CODE_ACTION_IN_PROGRESS;
+  }
 
 _OVER:
   if (code != 0 && code != TSDB_CODE_ACTION_IN_PROGRESS) {
diff --git a/tests/script/tsim/db/alter_replica_13.sim b/tests/script/tsim/db/alter_replica_13.sim
index 4eafb86198..d75acb50ad 100644
--- a/tests/script/tsim/db/alter_replica_13.sim
+++ b/tests/script/tsim/db/alter_replica_13.sim
@@ -116,6 +116,25 @@ endi
 
 print ============= step4: alter database
 sql alter database db replica 3
+$wt = 0
+stepwt1:
+ 	$wt = $wt + 1
+ 	sleep 1000
+ 	if $wt == 200 then
+ 	  print ====> dnode not ready!
+ 		return -1
+ 	endi
+sql show transactions
+if $rows != 0 then
+  print wait 1 seconds to alter
+  goto stepwt1
+endi
+
+sql show db.vgroups
+print ---> $data00 $data01 $data02 $data03 $data04 $data05 $data06 $data07 $data08 $data09
+print ---> $data10 $data11 $data12 $data13 $data14 $data15 $data16 $data27 $data28 $data29
+print ---> $data10 $data11 $data12 $data13 $data14 $data15 $data26 $data37 $data38 $data39
+print ---> $data10 $data11 $data12 $data13 $data14 $data15 $data36 $data47 $data48 $data49
 
 $leaderIndex = 0
 
diff --git a/tests/script/tsim/db/alter_replica_31.sim b/tests/script/tsim/db/alter_replica_31.sim
index 47e1fda79f..b689c9de10 100644
--- a/tests/script/tsim/db/alter_replica_31.sim
+++ b/tests/script/tsim/db/alter_replica_31.sim
@@ -148,6 +148,26 @@ endi
 
 print ============= step3: alter database
 sql alter database db replica 1
+wt = 0
+ stepwt1:
+ 	$wt = $wt + 1
+ 	sleep 1000
+ 	if $wt == 200 then
+ 	  print ====> dnode not ready!
+ 		return -1
+ 	endi
+sql show transactions
+if $rows != 0 then
+  print wait 1 seconds to alter
+  goto stepwt1
+endi
+
+sql show db.vgroups
+print ---> $data00 $data01 $data02 $data03 $data04 $data05 $data06 $data07 $data08 $data09
+print ---> $data10 $data11 $data12 $data13 $data14 $data15 $data16 $data27 $data28 $data29
+print ---> $data10 $data11 $data12 $data13 $data14 $data15 $data26 $data37 $data38 $data39
+print ---> $data10 $data11 $data12 $data13 $data14 $data15 $data36 $data47 $data48 $data49
+
 $hasleader = 0
 
 $x = 0