restore old change replica

source/dnode/mnode/impl/inc/mndVgroup.h

@@ -47,6 +47,8 @@ int32_t mndBuildAlterVgroupAction(SMnode *pMnode, STrans *pTrans, SDbObj *pOldDb
                                   SArray *pArray);
 int32_t mndBuildCompactVgroupAction(SMnode *pMnode, STrans *pTrans, SDbObj *pDb, SVgObj *pVgroup, int64_t compactTs,
                                     STimeWindow tw);
+int32_t mndBuildRaftAlterVgroupAction(SMnode *pMnode, STrans *pTrans, SDbObj *pOldDb, SDbObj *pNewDb, SVgObj *pVgroup,
+                                  SArray *pArray);
 
 void *mndBuildCreateVnodeReq(SMnode *, SDnodeObj *pDnode, SDbObj *pDb, SVgObj *pVgroup, int32_t *pContLen);
 void *mndBuildDropVnodeReq(SMnode *, SDnodeObj *pDnode, SDbObj *pDb, SVgObj *pVgroup, int32_t *pContLen);

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

@@ -852,7 +852,7 @@ static int32_t mndSetAlterDbRedoActions(SMnode *pMnode, STrans *pTrans, SDbObj *
     if (pIter == NULL) break;
 
     if (mndVgroupInDb(pVgroup, pNewDb->uid)) {
-      if (mndBuildAlterVgroupAction(pMnode, pTrans, pOldDb, pNewDb, pVgroup, pArray) != 0) {
+      if (mndBuildRaftAlterVgroupAction(pMnode, pTrans, pOldDb, pNewDb, pVgroup, pArray) != 0) {
         sdbCancelFetch(pSdb, pIter);
         sdbRelease(pSdb, pVgroup);
         taosArrayDestroy(pArray);

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

@@ -1428,6 +1428,32 @@ int32_t mndAddCheckLearnerCatchupAction(SMnode *pMnode, STrans *pTrans, SDbObj *
   return 0;
 }
 
+int32_t mndAddAlterVnodeTypeAction(SMnode *pMnode, STrans *pTrans, SDbObj *pDb, SVgObj *pVgroup, int32_t dnodeId) {
+  SDnodeObj *pDnode = mndAcquireDnode(pMnode, dnodeId);
+  if (pDnode == NULL) return -1;
+
+  STransAction action = {0};
+  action.epSet = mndGetDnodeEpset(pDnode);
+  mndReleaseDnode(pMnode, pDnode);
+
+  int32_t contLen = 0;
+  void   *pReq = mndBuildAlterVnodeReplicaReq(pMnode, pDb, pVgroup, dnodeId, &contLen);
+  if (pReq == NULL) return -1;
+
+  action.pCont = pReq;
+  action.contLen = contLen;
+  action.msgType = TDMT_DND_ALTER_VNODE_TYPE;
+  action.acceptableCode = TSDB_CODE_VND_ALREADY_IS_VOTER;
+  action.retryCode = TSDB_CODE_VND_NOT_CATCH_UP;
+
+  if (mndTransAppendRedoAction(pTrans, &action) != 0) {
+    taosMemoryFree(pReq);
+    return -1;
+  }
+
+  return 0;
+}
+
 int32_t mndRestoreAddAlterVnodeTypeAction(SMnode *pMnode, STrans *pTrans, SDbObj *pDb, SVgObj *pVgroup,
                                           SDnodeObj *pDnode) {
   STransAction action = {0};
@@ -2244,6 +2270,94 @@ int32_t mndBuildAlterVgroupAction(SMnode *pMnode, STrans *pTrans, SDbObj *pOldDb
 
   mndTransSetSerial(pTrans);
 
+  if (newVgroup.replica == 1 && pNewDb->cfg.replications == 3) {
+    mInfo("db:%s, vgId:%d, will add 2 vnodes, vn:0 dnode:%d", pVgroup->dbName, pVgroup->vgId,
+          pVgroup->vnodeGid[0].dnodeId);
+
+    //add second
+    if (mndAddVnodeToVgroup(pMnode, pTrans, &newVgroup, pArray) != 0) return -1;
+
+    //learner stage
+    newVgroup.vnodeGid[0].nodeRole = TAOS_SYNC_ROLE_VOTER;
+    newVgroup.vnodeGid[1].nodeRole = TAOS_SYNC_ROLE_LEARNER;
+    if (mndAddAlterVnodeReplicaAction(pMnode, pTrans, pNewDb, &newVgroup, newVgroup.vnodeGid[0].dnodeId) != 0)
+      return -1;
+
+    if (mndAddCreateVnodeAction(pMnode, pTrans, pNewDb, &newVgroup, &newVgroup.vnodeGid[1]) != 0) return -1;
+
+    //follower stage
+    newVgroup.vnodeGid[1].nodeRole = TAOS_SYNC_ROLE_VOTER;
+    if (mndAddAlterVnodeTypeAction(pMnode, pTrans, pNewDb, &newVgroup, newVgroup.vnodeGid[1].dnodeId) != 0)
+      return -1;
+    if (mndAddAlterVnodeReplicaAction(pMnode, pTrans, pNewDb, &newVgroup, newVgroup.vnodeGid[0].dnodeId) != 0)
+      return -1;
+
+    if (mndAddAlterVnodeConfirmAction(pMnode, pTrans, pNewDb, &newVgroup) != 0) return -1;
+
+    //add third
+    if (mndAddVnodeToVgroup(pMnode, pTrans, &newVgroup, pArray) != 0) return -1;
+
+    newVgroup.vnodeGid[0].nodeRole = TAOS_SYNC_ROLE_VOTER;
+    newVgroup.vnodeGid[1].nodeRole = TAOS_SYNC_ROLE_VOTER;
+    newVgroup.vnodeGid[2].nodeRole = TAOS_SYNC_ROLE_VOTER;
+    if (mndAddAlterVnodeReplicaAction(pMnode, pTrans, pNewDb, &newVgroup, newVgroup.vnodeGid[0].dnodeId) != 0)
+      return -1;
+    if (mndAddAlterVnodeReplicaAction(pMnode, pTrans, pNewDb, &newVgroup, newVgroup.vnodeGid[1].dnodeId) != 0)
+      return -1;
+    if (mndAddCreateVnodeAction(pMnode, pTrans, pNewDb, &newVgroup, &newVgroup.vnodeGid[2]) != 0) return -1;
+
+    if (mndAddAlterVnodeConfirmAction(pMnode, pTrans, pNewDb, &newVgroup) != 0) return -1;
+  } else if (newVgroup.replica == 3 && pNewDb->cfg.replications == 1) {
+    mInfo("db:%s, vgId:%d, will remove 2 vnodes, vn:0 dnode:%d vn:1 dnode:%d vn:2 dnode:%d", pVgroup->dbName,
+          pVgroup->vgId, pVgroup->vnodeGid[0].dnodeId, pVgroup->vnodeGid[1].dnodeId, pVgroup->vnodeGid[2].dnodeId);
+
+    SVnodeGid del1 = {0};
+    SVnodeGid del2 = {0};
+    if (mndRemoveVnodeFromVgroup(pMnode, pTrans, &newVgroup, pArray, &del1) != 0) return -1;
+    if (mndAddDropVnodeAction(pMnode, pTrans, pNewDb, &newVgroup, &del1, true) != 0) return -1;
+    if (mndAddAlterVnodeReplicaAction(pMnode, pTrans, pNewDb, &newVgroup, newVgroup.vnodeGid[0].dnodeId) != 0)
+      return -1;
+    if (mndAddAlterVnodeReplicaAction(pMnode, pTrans, pNewDb, &newVgroup, newVgroup.vnodeGid[1].dnodeId) != 0)
+      return -1;
+    if (mndAddAlterVnodeConfirmAction(pMnode, pTrans, pNewDb, &newVgroup) != 0) return -1;
+
+    if (mndRemoveVnodeFromVgroup(pMnode, pTrans, &newVgroup, pArray, &del2) != 0) return -1;
+    if (mndAddDropVnodeAction(pMnode, pTrans, pNewDb, &newVgroup, &del2, true) != 0) return -1;
+    if (mndAddAlterVnodeReplicaAction(pMnode, pTrans, pNewDb, &newVgroup, newVgroup.vnodeGid[0].dnodeId) != 0)
+      return -1;
+    if (mndAddAlterVnodeConfirmAction(pMnode, pTrans, pNewDb, &newVgroup) != 0) return -1;
+  } else {
+    return -1;
+  }
+
+  mndSortVnodeGid(&newVgroup);
+
+  {
+    SSdbRaw *pVgRaw = mndVgroupActionEncode(&newVgroup);
+    if (pVgRaw == NULL) return -1;
+    if (mndTransAppendCommitlog(pTrans, pVgRaw) != 0) {
+      sdbFreeRaw(pVgRaw);
+      return -1;
+    }
+    (void)sdbSetRawStatus(pVgRaw, SDB_STATUS_READY);
+  }
+
+  return 0;
+}
+
+int32_t mndBuildRaftAlterVgroupAction(SMnode *pMnode, STrans *pTrans, SDbObj *pOldDb, SDbObj *pNewDb, SVgObj *pVgroup,
+                                  SArray *pArray) {
+  SVgObj newVgroup = {0};
+  memcpy(&newVgroup, pVgroup, sizeof(SVgObj));
+
+  if (pVgroup->replica <= 0 || pVgroup->replica == pNewDb->cfg.replications) {
+    if (mndAddAlterVnodeConfigAction(pMnode, pTrans, pNewDb, pVgroup) != 0) return -1;
+    if (mndCheckDnodeMemory(pMnode, pOldDb, pNewDb, &newVgroup, pVgroup, pArray) != 0) return -1;
+    return 0;
+  }
+
+  mndTransSetSerial(pTrans);
+
   mInfo("trans:%d, vgid:%d alter vgroup, syncConfChangeVer:%d, version:%d, replica:%d", 
         pTrans->id, pVgroup->vgId, pVgroup->syncConfChangeVer, pVgroup->version, pVgroup->replica);