HDDS-11187. Fix Event Handling in Recon OMDBUpdatesHandler to Prevent ClassCastException

hadoop-ozone/recon/src/main/java/org/apache/hadoop/ozone/recon/tasks/OMDBUpdatesHandler.java

@@ -48,8 +48,7 @@ public class OMDBUpdatesHandler extends ManagedWriteBatch.Handler {
   private Map<Integer, String> tablesNames;
   private OMMetadataManager omMetadataManager;
   private List<OMDBUpdateEvent> omdbUpdateEvents = new ArrayList<>();
-  private Map<Object, OMDBUpdateEvent> omdbLatestUpdateEvents
-      = new HashMap<>();
+  private Map<String, Map<Object, OMDBUpdateEvent>> omdbLatestUpdateEvents = new HashMap<>();
   private OMDBDefinition omdbDefinition;
   private OmUpdateEventValidator omUpdateEventValidator;
 
@@ -112,6 +111,10 @@ private void processEvent(int cfIndex, byte[] keyBytes, byte[]
       final Object key = cf.getKeyCodec().fromPersistedFormat(keyBytes);
       builder.setKey(key);
 
+      // Initialize table-specific event map if it does not exist
+      omdbLatestUpdateEvents.putIfAbsent(tableName, new HashMap<>());
+      Map<Object, OMDBUpdateEvent> tableEventsMap = omdbLatestUpdateEvents.get(tableName);
+
       // Handle the event based on its type:
       // - PUT with a new key: Insert the new value.
       // - PUT with an existing key: Update the existing value.
@@ -120,7 +123,7 @@ private void processEvent(int cfIndex, byte[] keyBytes, byte[]
       // necessary.
       Table table = omMetadataManager.getTable(tableName);
 
-      OMDBUpdateEvent latestEvent = omdbLatestUpdateEvents.get(key);
+      OMDBUpdateEvent latestEvent = tableEventsMap.get(key);
       Object oldValue;
       if (latestEvent != null) {
         oldValue = latestEvent.getValue();
@@ -184,7 +187,7 @@ private void processEvent(int cfIndex, byte[] keyBytes, byte[]
                 "action = %s", tableName, action));
       }
       omdbUpdateEvents.add(event);
-      omdbLatestUpdateEvents.put(key, event);
+      tableEventsMap.put(key, event);
     } else {
       // Log and ignore events if key or value types are undetermined.
       if (LOG.isWarnEnabled()) {

hadoop-ozone/recon/src/test/java/org/apache/hadoop/ozone/recon/tasks/TestOMDBUpdatesHandler.java

@@ -42,6 +42,8 @@
 import org.apache.hadoop.ozone.om.OMMetadataManager;
 import org.apache.hadoop.ozone.om.OmMetadataManagerImpl;
 import org.apache.hadoop.ozone.om.codec.OMDBDefinition;
+import org.apache.hadoop.ozone.om.helpers.RepeatedOmKeyInfo;
+import org.apache.hadoop.ozone.om.helpers.OmDirectoryInfo;
 import org.apache.hadoop.ozone.om.helpers.BucketLayout;
 import org.apache.hadoop.ozone.om.helpers.OmBucketInfo;
 import org.apache.hadoop.ozone.om.helpers.OmKeyInfo;
@@ -286,6 +288,71 @@ public void testOperateOnSameEntry() throws Exception {
         ((OmKeyInfo)keyPut2.getOldValue()).getKeyName());
   }
 
+  /**
+   * Test to verify that events with duplicate keys in different tables
+   * (FileTable and DirectoryTable) are handled correctly without causing
+   * ClassCastException or event conflicts.
+   *
+   * This test simulates creating a file, deleting the file, and then creating
+   * a directory with the same name under the same parent ID in different tables.
+   * It ensures that the events are correctly processed and stored in the
+   * `omdbLatestUpdateEvents` map without causing any type mismatches or
+   * exceptions.
+   *
+   * @throws Exception if any error occurs during the test execution.
+   */
+  @Test
+  public void testEventsHavingDuplicateRocksDBKey() throws Exception {
+    // Step 1: Create a file with the name "sameName" in the fileTable
+    OmKeyInfo fileKeyInfo = getOmKeyInfo("sampleVol", "bucketOne", "sameName");
+    omMetadataManager.getFileTable().put("/sampleVol/bucketOne/parentId/sameName", fileKeyInfo);
+
+    // Step 2: Delete the file by adding its information to the deletedTable
+    RepeatedOmKeyInfo repeatedKeyInfo = new RepeatedOmKeyInfo(fileKeyInfo);
+    omMetadataManager.getDeletedTable().put("/sampleVol/bucketOne/parentId/sameName", repeatedKeyInfo);
+
+    // Step 3: Create a directory with the same name "sameName" in the directoryTable
+    OmDirectoryInfo dirInfo = OmDirectoryInfo.newBuilder()
+        .setName("sameName")
+        .setParentObjectID(fileKeyInfo.getParentObjectID())
+        .setObjectID(fileKeyInfo.getObjectID())
+        .setCreationTime(System.currentTimeMillis())
+        .setModificationTime(System.currentTimeMillis())
+        .build();
+    omMetadataManager.getDirectoryTable().put("/sampleVol/bucketOne/parentId/sameName", dirInfo);
+
+    // Capture the events from the OM Metadata Manager
+    List<byte[]> writeBatches = getBytesFromOmMetaManager(0);
+    OMDBUpdatesHandler omdbUpdatesHandler = captureEvents(writeBatches);
+
+    // Retrieve the captured events and assert the correct number of events
+    List<OMDBUpdateEvent> events = omdbUpdatesHandler.getEvents();
+    // Verify no events were discarded
+    assertEquals(3, events.size());
+
+    // Validate the file creation event
+    OMDBUpdateEvent filePutEvent = events.get(0);
+    assertEquals(PUT, filePutEvent.getAction());
+    assertEquals("/sampleVol/bucketOne/parentId/sameName", filePutEvent.getKey());
+    assertEquals("sameName", ((OmKeyInfo) filePutEvent.getValue()).getKeyName());
+    assertNull(filePutEvent.getOldValue());
+
+    // Validate the file deletion event
+    OMDBUpdateEvent fileDeleteEvent = events.get(1);
+    assertEquals(PUT, fileDeleteEvent.getAction());
+    assertEquals("/sampleVol/bucketOne/parentId/sameName", fileDeleteEvent.getKey());
+    assertEquals("sameName",
+        ((RepeatedOmKeyInfo) fileDeleteEvent.getValue()).getOmKeyInfoList().get(0).getKeyName());
+
+    // Validate the directory creation event
+    OMDBUpdateEvent dirPutEvent = events.get(2);
+    assertEquals(PUT, dirPutEvent.getAction());
+    assertEquals("/sampleVol/bucketOne/parentId/sameName", dirPutEvent.getKey());
+    assertEquals("sameName", ((OmDirectoryInfo) dirPutEvent.getValue()).getName());
+    // There will be no old value as the key was not present in the directoryTable before
+    assertNull(dirPutEvent.getOldValue());
+  }
+
   @Test
   public void testGetKeyType() throws IOException {
     final String keyTable = omMetadataManager