[IOTDB-4222] Create data region repeatedly when concurrently deleting…

… and creating storage groups (#7112)
apache · on Aug 25 · 94657cf836ea6407cfd374f36324333e8194b919 · 94657cf
1 parent 2513190
commit 94657cf836ea6407cfd374f36324333e8194b919
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/...src/main/java/org/apache/iotdb/db/engine/storagegroup/dataregion/StorageGroupManager.java b/...src/main/java/org/apache/iotdb/db/engine/storagegroup/dataregion/StorageGroupManager.java
   }
 
   @SuppressWarnings("java:S2445")
-  // actually storageGroupMNode is a unique object on the mtree, synchronize it is reasonable
   public DataRegion getProcessor(IStorageGroupMNode storageGroupMNode, int dataRegionId)
       throws DataRegionException, StorageEngineException {
     DataRegion processor = dataRegion[dataRegionId];
     if (processor == null) {
       // if finish recover
       if (isDataRegionReady[dataRegionId].get()) {
-        synchronized (storageGroupMNode) {
+        // it's unsafe to synchronize MNode here because
+        // concurrent deletions and creations will create a new MNode
+        synchronized (isDataRegionReady[dataRegionId]) {
           processor = dataRegion[dataRegionId];
           if (processor == null) {
             processor =
                StorageEngine.getInstance()
                    .buildNewStorageGroupProcessor(
                        storageGroupMNode.getPartialPath(),
                        storageGroupMNode,
                        String.valueOf(dataRegionId));
            dataRegion[dataRegionId] = processor;
          }
        }
      } else {
        // not finished recover, refuse the request
        throw new StorageGroupNotReadyException(
            storageGroupMNode.getFullPath(), TSStatusCode.STORAGE_GROUP_NOT_READY.getStatusCode());
      }
    }

    return processor;
  }

  /**