Fix duplicate peer in createNewRegionPeer; harden reconstruct IT

Author: CRZbulabula

integration-test/src/test/java/org/apache/iotdb/confignode/it/regionmigration/IoTDBRegionOperationReliabilityITFramework.java

@@ -736,4 +736,23 @@ protected static Map<Integer, String> getRegionStatusWithoutRunning(Session sess
     }
     return result;
   }
+
+  /** Returns regionId -> dataNodeId -> status as reported by {@code show regions}. */
+  protected static Map<Integer, Map<Integer, String>> getRegionStatusMap(Session session)
+      throws IoTDBConnectionException, StatementExecutionException {
+    SessionDataSet dataSet = session.executeQueryStatement("show regions");
+    final int regionIdIndex = dataSet.getColumnNames().indexOf("RegionId");
+    final int dataNodeIdIndex = dataSet.getColumnNames().indexOf("DataNodeId");
+    final int regionStatusIndex = dataSet.getColumnNames().indexOf("Status");
+    dataSet.setFetchSize(1024);
+    Map<Integer, Map<Integer, String>> result = new TreeMap<>();
+    while (dataSet.hasNext()) {
+      List<Field> fields = dataSet.next().getFields();
+      final int regionId = fields.get(regionIdIndex).getIntV();
+      final int dataNodeId = fields.get(dataNodeIdIndex).getIntV();
+      final String regionStatus = fields.get(regionStatusIndex).toString();
+      result.computeIfAbsent(regionId, k -> new TreeMap<>()).put(dataNodeId, regionStatus);
+    }
+    return result;
+  }
 }

integration-test/src/test/java/org/apache/iotdb/confignode/it/regionmigration/pass/commit/IoTDBRegionReconstructForIoTV1IT.java

@@ -46,6 +46,7 @@
 import java.io.File;
 import java.sql.Connection;
 import java.sql.Statement;
+import java.util.Collections;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
@@ -108,7 +109,9 @@ public void normal1C3DTest() throws Exception {
       Assert.assertTrue(dataRegionMap.containsKey(selectedRegion));
       Pair<Integer, Set<Integer>> leaderAndNodeIds = dataRegionMap.get(selectedRegion);
       Assert.assertEquals(2, leaderAndNodeIds.right.size());
-      // reconstruct from the leader to ensure no data is lost
+      // Stop the current leader; reconstruct will later target the surviving follower (whose
+      // tsfiles get deleted below). When the original leader is restarted, the follower's
+      // missing data is replicated back from it, so no committed data is lost.
       final int dataNodeToBeClosed = leaderAndNodeIds.left;
       final int dataNodeToBeReconstructed =
           leaderAndNodeIds.right.stream().filter(x -> x != dataNodeToBeClosed).findAny().get();
@@ -172,19 +175,25 @@ public void normal1C3DTest() throws Exception {
       EnvFactory.getAbstractEnv().checkNodeInStatus(dataNodeToBeClosed, NodeStatus.Running);
       session.executeNonQueryStatement(
           String.format(RECONSTRUCT_FORMAT, selectedRegion, dataNodeToBeReconstructed));
+      // Confirm reconstruct succeeded: the selected region must contain both the reconstructed
+      // peer and the (formerly closed) peer, with both rows reporting Running.
       try {
         Awaitility.await()
             .pollInterval(1, TimeUnit.SECONDS)
             .atMost(10, TimeUnit.MINUTES)
             .until(
-                () ->
-                    getRegionStatusWithoutRunning(session).isEmpty()
-                        && dataDirToBeReconstructed.getAbsoluteFile().exists());
+                () -> {
+                  Map<Integer, String> peerStatus =
+                      getRegionStatusMap(session)
+                          .getOrDefault(selectedRegion, Collections.emptyMap());
+                  return "Running".equals(peerStatus.get(dataNodeToBeReconstructed))
+                      && "Running".equals(peerStatus.get(dataNodeToBeClosed));
+                });
       } catch (Exception e) {
         LOGGER.error(
-            "Two factor: {} && {}",
-            getRegionStatusWithoutRunning(session),
-            dataDirToBeReconstructed.getAbsoluteFile().exists());
+            "Reconstruct did not finish in time. region {} status map: {}",
+            selectedRegion,
+            getRegionStatusMap(session).get(selectedRegion));
         fail();
       }
       EnvFactory.getEnv().dataNodeIdToWrapper(dataNodeToBeClosed).get().stopForcibly();

iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/procedure/env/RegionMaintainHandler.java

@@ -175,9 +175,14 @@ public TSStatus createNewRegionPeer(TConsensusGroupId regionId, TDataNodeLocatio
     if (TConsensusGroupType.DataRegion.equals(regionId.getType())
         && (IOT_CONSENSUS.equals(CONF.getDataRegionConsensusProtocolClass())
             || IOT_CONSENSUS_V2.equals(CONF.getDataRegionConsensusProtocolClass()))) {
-      // parameter of createPeer for MultiLeader should be all peers
+      // parameter of createPeer for MultiLeader should be all peers; callers (e.g.
+      // AddRegionPeerProcedure) may have already inserted destDataNode into the partition
+      // table before reaching here, so append only when not already present to avoid
+      // sending a peer list with duplicates.
       currentPeerNodes = new ArrayList<>(regionReplicaNodes);
-      currentPeerNodes.add(destDataNode);
+      if (!currentPeerNodes.contains(destDataNode)) {
+        currentPeerNodes.add(destDataNode);
+      }
     } else {
       // parameter of createPeer for Ratis can be empty
       currentPeerNodes = Collections.emptyList();