feat: balance vgroup

include/util/taoserror.h

@@ -219,6 +219,7 @@ int32_t* taosGetErrno();
 #define TSDB_CODE_MND_VGROUP_NOT_IN_DNODE       TAOS_DEF_ERROR_CODE(0, 0x0391)
 #define TSDB_CODE_MND_VGROUP_ALREADY_IN_DNODE   TAOS_DEF_ERROR_CODE(0, 0x0392)
 #define TSDB_CODE_MND_VGROUP_UN_CHANGED         TAOS_DEF_ERROR_CODE(0, 0x0393)
+#define TSDB_CODE_MND_HAS_OFFLINE_DNODE         TAOS_DEF_ERROR_CODE(0, 0x0394)
 
 // mnode-stable
 #define TSDB_CODE_MND_STB_ALREADY_EXIST         TAOS_DEF_ERROR_CODE(0, 0x03A0)

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

@@ -38,6 +38,7 @@ static void    mndCancelGetNextVnode(SMnode *pMnode, void *pIter);
 
 static int32_t mndProcessRedistributeVgroupMsg(SRpcMsg *pReq);
 static int32_t mndProcessSplitVgroupMsg(SRpcMsg *pReq);
+static int32_t mndProcessBalanceVgroupMsg(SRpcMsg *pReq);
 
 int32_t mndInitVgroup(SMnode *pMnode) {
   SSdbTable table = {
@@ -1165,4 +1166,159 @@ _OVER:
   return code;
 }
 
-static int32_t mndProcessSplitVgroupMsg(SRpcMsg *pReq) { return 0; }
\ No newline at end of file
+static int32_t mndProcessSplitVgroupMsg(SRpcMsg *pReq) { return 0; }
+
+static int32_t mndSetBalanceVgroupInfoToTrans(SMnode *pMnode, STrans *pTrans, SDbObj *pDb, SVgObj *pVgroup,
+                                              SDnodeObj *pSrc, SDnodeObj *pDst) {
+  SVgObj newVg = {0};
+  memcpy(&newVg, pVgroup, sizeof(SVgObj));
+  mInfo("vgId:%d, vgroup info before balance, replica:%d", newVg.vgId, newVg.replica);
+  for (int32_t i = 0; i < newVg.replica; ++i) {
+    mInfo("vgId:%d, vnode:%d dnode:%d", newVg.vgId, i, newVg.vnodeGid[i].dnodeId);
+  }
+
+  if (mndAddIncVgroupReplicaToTrans(pMnode, pTrans, pDb, &newVg, pDst->id) != 0) return -1;
+  if (mndAddDecVgroupReplicaFromTrans(pMnode, pTrans, pDb, &newVg, pSrc->id) != 0) return -1;
+
+  SSdbRaw *pRaw = mndVgroupActionEncode(&newVg);
+  if (pRaw == NULL || mndTransAppendCommitlog(pTrans, pRaw) != 0) {
+    sdbFreeRaw(pRaw);
+    return -1;
+  }
+  sdbSetRawStatus(pRaw, SDB_STATUS_READY);
+
+  mInfo("vgId:%d, vgroup info after balance, replica:%d", newVg.vgId, newVg.replica);
+  for (int32_t i = 0; i < newVg.replica; ++i) {
+    mInfo("vgId:%d, vnode:%d dnode:%d", newVg.vgId, i, newVg.vnodeGid[i].dnodeId);
+  }
+  return 0;
+}
+
+static int32_t mndBalanceVgroupBetweenDnode(SMnode *pMnode, STrans *pTrans, SDnodeObj *pSrc, SDnodeObj *pDst) {
+  void   *pIter = NULL;
+  int32_t code = -1;
+
+  while (1) {
+    SVgObj *pVgroup = NULL;
+    pIter = sdbFetch(pMnode->pSdb, SDB_VGROUP, pIter, (void **)&pVgroup);
+    if (pIter == NULL) break;
+
+    bool existInSrc = false;
+    bool existInDst = false;
+    for (int32_t i = 0; i < pVgroup->replica; ++i) {
+      SVnodeGid *pGid = &pVgroup->vnodeGid[i];
+      if (pGid->dnodeId == pSrc->id) existInSrc = true;
+      if (pGid->dnodeId == pDst->id) existInDst = true;
+    }
+
+    if (!existInSrc || existInDst) {
+      sdbRelease(pMnode->pSdb, pVgroup);
+    }
+
+    SDbObj *pDb = mndAcquireDb(pMnode, pVgroup->dbName);
+    code = mndSetBalanceVgroupInfoToTrans(pMnode, pTrans, pDb, pVgroup, pSrc, pDst);
+    mndReleaseDb(pMnode, pDb);
+    sdbRelease(pMnode->pSdb, pVgroup);
+    break;
+  }
+
+  return code;
+}
+
+static int32_t mndBalanceVgroup(SMnode *pMnode, SRpcMsg *pReq, SArray *pArray) {
+  int32_t code = -1;
+  int32_t numOfVgroups = 0;
+  STrans *pTrans = NULL;
+
+  pTrans = mndTransCreate(pMnode, TRN_POLICY_RETRY, TRN_CONFLICT_GLOBAL, pReq);
+  if (pTrans == NULL) goto _OVER;
+  mndTransSetSerial(pTrans);
+  mDebug("trans:%d, used to balance vgroup", pTrans->id);
+
+  while (1) {
+    taosArraySort(pArray, (__compar_fn_t)mndCompareDnodeVnodes);
+    SDnodeObj *pSrc = taosArrayGet(pArray, 0);
+    SDnodeObj *pDst = taosArrayGet(pArray, taosArrayGetSize(pArray) - 1);
+
+    float srcScore = (float)(pSrc->numOfVnodes - 1) / pSrc->numOfSupportVnodes;
+    float dstScore = (float)(pDst->numOfVnodes + 1) / pDst->numOfSupportVnodes;
+    if (srcScore + 0.0001 < dstScore) {
+      mDebug("trans:%d, balance vgroup from dnode:%d to dnode:%d", pTrans->id, pSrc->id, pDst->id);
+      code = mndBalanceVgroupBetweenDnode(pMnode, pTrans, pSrc, pDst);
+      if (code == 0) {
+        numOfVgroups++;
+        continue;
+      } else {
+        mError("trans:%d, failed to balance vgroup from dnode:%d to dnode:%d", pTrans->id, pSrc->id, pDst->id);
+        return -1;
+      }
+    } else {
+      mDebug("trans:%d, no vgroup need to balance vgroup any more", pTrans->id);
+      break;
+    }
+  }
+
+  if (numOfVgroups <= 0) {
+    mDebug("no need to balance vgroup");
+    code = 0;
+  } else {
+    mDebug("start to balance vgroup, numOfVgroups:%d", numOfVgroups);
+    if (mndTransPrepare(pMnode, pTrans) != 0) goto _OVER;
+    code = TSDB_CODE_ACTION_IN_PROGRESS;
+  }
+
+_OVER:
+  mndTransDrop(pTrans);
+  return code;
+}
+
+static int32_t mndProcessBalanceVgroupMsg(SRpcMsg *pReq) {
+  SMnode   *pMnode = pReq->info.node;
+  int32_t   code = -1;
+  SUserObj *pUser = NULL;
+  SArray   *pArray = NULL;
+  void     *pIter = NULL;
+  int64_t   curMs = taosGetTimestampMs();
+
+  mDebug("start to balance vgroup");
+  pUser = mndAcquireUser(pMnode, pReq->conn.user);
+  if (pUser == NULL) {
+    terrno = TSDB_CODE_MND_NO_USER_FROM_CONN;
+    goto _OVER;
+  }
+
+  if (mndCheckNodeAuth(pUser) != 0) goto _OVER;
+
+  while (1) {
+    SDnodeObj *pDnode = NULL;
+    pIter = sdbFetch(pMnode->pSdb, SDB_DNODE, pIter, (void **)&pDnode);
+    if (pIter == NULL) break;
+    if (!mndIsDnodeOnline(pDnode, curMs)) {
+      terrno = TSDB_CODE_MND_HAS_OFFLINE_DNODE;
+      mError("failed to balance vgroup since %s, dnode:%d", terrstr(), pDnode->id);
+      sdbRelease(pMnode->pSdb, pDnode);
+      goto _OVER;
+    }
+
+    sdbRelease(pMnode->pSdb, pDnode);
+  }
+
+  pArray = mndBuildDnodesArray(pMnode, 0);
+  if (pArray == NULL) goto _OVER;
+
+  if (taosArrayGetSize(pArray) < 2) {
+    mDebug("no need to balance vgroup since dnode num less than 2");
+    code = 0;
+  } else {
+    code = mndBalanceVgroup(pMnode, pReq, pArray);
+  }
+
+_OVER:
+  if (code != 0 && code != TSDB_CODE_ACTION_IN_PROGRESS) {
+    mError("failed to balance vgroup since %s", terrstr());
+  }
+
+  mndReleaseUser(pMnode, pUser);
+  taosArrayDestroy(pArray);
+  return code;
+}
\ No newline at end of file

source/util/src/terror.c

@@ -222,7 +222,9 @@ TAOS_DEFINE_ERROR(TSDB_CODE_MND_DB_INDEX_NOT_EXIST,       "Index not exist")
 // mnode-vgroup
 TAOS_DEFINE_ERROR(TSDB_CODE_MND_VGROUP_ALREADY_IN_DNODE,  "Vgroup already in dnode")
 TAOS_DEFINE_ERROR(TSDB_CODE_MND_VGROUP_NOT_IN_DNODE,      "Vgroup not in dnode")
-TAOS_DEFINE_ERROR(TSDB_CODE_MND_VGROUP_NOT_EXIST,         "VGroup does not exist")
+TAOS_DEFINE_ERROR(TSDB_CODE_MND_VGROUP_NOT_EXIST,         "Vgroup does not exist")
+TAOS_DEFINE_ERROR(TSDB_CODE_MND_VGROUP_UN_CHANGED,        "Vgroup distribution has not changed")
+TAOS_DEFINE_ERROR(TSDB_CODE_MND_HAS_OFFLINE_DNODE,        "Offline dnode exists")
 
 // mnode-stable
 TAOS_DEFINE_ERROR(TSDB_CODE_MND_STB_ALREADY_EXIST,        "STable already exists")