9477: Direct memory / data source leak if teacher becomes inaccessible during reconnect

platform-sdk/swirlds-jasperdb/src/main/java/com/swirlds/merkledb/MerkleDb.java

@@ -461,25 +461,10 @@ public <K extends VirtualKey, V extends VirtualValue> void closeDataSource(
         final int tableId = dataSource.getTableId();
         assert dataSources.get(tableId) != null;
         dataSources.set(tableId, null);
-        if (!primaryTables.contains(tableId)) {
-            // Delete data, if the table is secondary
-            removeTable(tableId);
-        }
-    }
-
-    /**
-     * For testing purpose only.
-     *
-     * Removes the table. Table config and table data files are deleted.
-     *
-     * @param tableId ID of the table to remove
-     */
-    void removeTable(final int tableId) {
         final TableMetadata metadata = tableConfigs.get(tableId);
         if (metadata == null) {
             throw new IllegalArgumentException("Unknown table ID: " + tableId);
         }
-        assert dataSources.get(tableId) == null; // data source must have been already closed
         final String label = metadata.tableName();
         tableConfigs.set(tableId, null);
         DataFileCommon.deleteDirectoryAndContents(getTableDir(label, tableId));

platform-sdk/swirlds-jasperdb/src/main/java/com/swirlds/merkledb/MerkleDbDataSource.java

@@ -757,19 +757,6 @@ public boolean loadAndWriteHash(long path, SerializableDataOutputStream out) thr
         return true;
     }
 
-    /**
-     * Wait for any merges to finish and then close all data stores.
-     * <p>
-     * <b>After closing delete the database directory and all data!</b> For testing purpose only.
-     */
-    public void closeAndDelete() throws IOException {
-        try {
-            close();
-        } finally {
-            database.removeTable(tableId);
-        }
-    }
-
     /** Wait for any merges to finish, then close all data stores and free all resources. */
     @Override
     public void close() throws IOException {

platform-sdk/swirlds-jasperdb/src/test/java/com/swirlds/merkledb/MerkleDbDataSourceMetricsTest.java

@@ -181,7 +181,7 @@ void createAndCheckLeaves() throws IOException {
 
     @AfterEach
     public void afterEach() throws IOException {
-        dataSource.closeAndDelete();
+        dataSource.close();
         assertEventuallyEquals(
                 0L, MerkleDbDataSource::getCountOfOpenDatabases, Duration.ofSeconds(1), "Expected no open dbs");
         // check the database was deleted

platform-sdk/swirlds-jasperdb/src/test/java/com/swirlds/merkledb/MerkleDbDataSourceTest.java

@@ -25,6 +25,7 @@
 import static com.swirlds.virtualmap.datasource.VirtualDataSource.INVALID_PATH;
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.junit.jupiter.api.Assertions.fail;
@@ -136,15 +137,15 @@ void createAndCheckInternalNodeHashes(final TestType testType, final int hashesR
         assertEquals("path is less than 0", e.getMessage(), "Detail message should capture the failure");
 
         // close data source
-        dataSource.closeAndDelete();
+        dataSource.close();
         // check db count
         assertEventuallyEquals(
                 0L, MerkleDbDataSource::getCountOfOpenDatabases, Duration.ofSeconds(1), "Expected no open dbs");
         // check the database was deleted
         assertEventuallyFalse(
                 () -> Files.exists(testDirectory.resolve(tableName)),
                 Duration.ofSeconds(1),
-                "Database should have been deleted by closeAndDelete()");
+                "Database should have been deleted by close()");
     }
 
     private static Stream<Arguments> provideParameters() {
@@ -202,11 +203,11 @@ void testRandomHashUpdates(final TestType testType) throws IOException {
         } catch (Exception e) {
             e.printStackTrace();
             // close data source
-            dataSource.closeAndDelete();
+            dataSource.close();
             System.exit(1);
         } finally {
             // close data source
-            dataSource.closeAndDelete();
+            dataSource.close();
         }
     }
 
@@ -238,7 +239,7 @@ void createAndCheckLeaves(final TestType testType) throws IOException {
         assertEquals("path is less than 0", e.getMessage(), "Detail message should capture the failure");
 
         // close data source
-        dataSource.closeAndDelete();
+        dataSource.close();
     }
 
     @ParameterizedTest
@@ -298,7 +299,7 @@ void updateLeaves(final TestType testType) throws IOException, InterruptedExcept
         IntStream.range(incFirstLeafPath + 21, exclLastLeafPath)
                 .forEach(i -> assertLeaf(testType, dataSource, i, i, i + 10_000));
         // close data source
-        dataSource.closeAndDelete();
+        dataSource.close();
 
         // check db count
         assertEventuallyEquals(
@@ -341,7 +342,7 @@ void moveLeaf(final TestType testType) throws IOException {
                 "creating/loading same LeafRecord gives different results");
         assertLeaf(testType, dataSource, 250, 500);
         // close data source
-        dataSource.closeAndDelete();
+        dataSource.close();
         // check db count
         assertEventuallyEquals(
                 0L, MerkleDbDataSource::getCountOfOpenDatabases, Duration.ofSeconds(1), "Expected no open dbs");
@@ -370,7 +371,7 @@ void preservesInterruptStatusWhenInterruptedSavingRecords() throws IOException,
                 "Thread interrupt status should NOT be cleared (two total interrupts)");
         savingThread.join();
         // close data source
-        dataSource.closeAndDelete();
+        dataSource.close();
         // check db count
         assertEventuallyEquals(
                 0L, MerkleDbDataSource::getCountOfOpenDatabases, Duration.ofSeconds(1), "Expected no open dbs");
@@ -401,10 +402,10 @@ void createCloseSnapshotCheckDelete(final TestType testType) throws IOException
         dataSource.getDatabase().snapshot(snapshotDbPath, dataSource);
         // close data source
         dataSource.close();
-        // check directory still exists and temporary snapshot path does not
-        assertTrue(
+        // check directory is deleted on close
+        assertFalse(
                 Files.exists(originalDb.getTableDir(tableName, dataSource.getTableId())),
-                "Database dir should still exist");
+                "Data source dir should be deleted");
         final MerkleDb snapshotDb = MerkleDb.getInstance(snapshotDbPath);
         assertTrue(
                 Files.exists(snapshotDb.getTableDir(tableName, dataSource.getTableId())),
@@ -415,7 +416,7 @@ void createCloseSnapshotCheckDelete(final TestType testType) throws IOException
         // check all the leaf data
         IntStream.range(count, count * 2).forEach(i -> assertLeaf(testType, dataSource2, i, i));
         // close data source
-        dataSource2.closeAndDelete();
+        dataSource2.close();
         // check db count
         assertEventuallyEquals(
                 0L, MerkleDbDataSource::getCountOfOpenDatabases, Duration.ofSeconds(1), "Expected no open dbs");
@@ -449,7 +450,7 @@ void preservesInterruptStatusWhenInterruptedClosing() throws IOException, Interr
         closingThread.join();
         savingThread.join();
         // close data source
-        dataSource.closeAndDelete();
+        dataSource.close();
         // check db count
         assertEventuallyEquals(
                 0L, MerkleDbDataSource::getCountOfOpenDatabases, Duration.ofSeconds(1), "Expected no open dbs");
@@ -505,7 +506,7 @@ void testKeyIndexTypes(final TestType testType) throws Exception {
                     "Data source in expected long key mode.");
         } finally {
             // close data source
-            dataSource.closeAndDelete();
+            dataSource.close();
         }
     }
 

platform-sdk/swirlds-jasperdb/src/test/java/com/swirlds/merkledb/MerkleDbTest.java

@@ -187,8 +187,8 @@ void testVirtualKeySet() throws IOException {
         Assertions.assertEquals(tableConfig, dataSource.getTableConfig());
         Assertions.assertEquals(tableConfig, instance.getTableConfig(tableId));
         dataSource.close();
-        // Table config is preserved across data source close/reopen
-        Assertions.assertNotNull(instance.getTableConfig(tableId));
+        // Table config deleted on data source close
+        Assertions.assertNull(instance.getTableConfig(tableId));
     }
 
     @Test
@@ -220,12 +220,7 @@ public void testGetDataSourceAfterClose() throws IOException {
                 instance.createDataSource(tableName, tableConfig, false);
         Assertions.assertNotNull(dataSource);
         dataSource.close();
-        final MerkleDbDataSource<ExampleLongKeyFixedSize, ExampleFixedSizeVirtualValue> dataSource2 =
-                instance.getDataSource(tableName, false);
-        Assertions.assertNotNull(dataSource2);
-        Assertions.assertEquals(dataSource2, dataSource);
-        Assertions.assertNotSame(dataSource2, dataSource);
-        dataSource2.close();
+        Assertions.assertThrows(IllegalStateException.class, () -> instance.getDataSource(tableName, false));
     }
 
     @Test
@@ -278,7 +273,6 @@ public void testSnapshot() throws IOException {
                 instance2.getDataSource(tableName1, false);
         Assertions.assertEquals(tableConfig, restored1.getTableConfig());
         restored1.close();
-        Assertions.assertEquals(tableConfig, instance2.getTableConfig(restored1.getTableId()));
         final MerkleDbDataSource<ExampleLongKeyFixedSize, ExampleFixedSizeVirtualValue> restored2 =
                 instance2.getDataSource(tableName2, false);
         Assertions.assertEquals(tableConfig, restored2.getTableConfig());
@@ -464,10 +458,10 @@ void testCopiedDataSourceAutoDeleted() throws IOException {
         inactiveCopy1.close();
         activeCopy2.close();
 
-        Assertions.assertTrue(Files.exists(instance.getTableDir(tableName1, dataSource1.getTableId())));
+        Assertions.assertFalse(Files.exists(instance.getTableDir(tableName1, dataSource1.getTableId())));
         Assertions.assertFalse(Files.exists(instance.getTableDir(tableName1, inactiveCopy1.getTableId())));
         Assertions.assertFalse(Files.exists(instance.getTableDir(tableName2, dataSource2.getTableId())));
-        Assertions.assertTrue(Files.exists(instance.getTableDir(tableName2, activeCopy2.getTableId())));
+        Assertions.assertFalse(Files.exists(instance.getTableDir(tableName2, activeCopy2.getTableId())));
     }
 
     @Test

platform-sdk/swirlds-virtualmap/src/main/java/com/swirlds/virtualmap/internal/merkle/VirtualRootNode.java

@@ -699,6 +699,12 @@ public VirtualRootNode<K, V> copy() {
     protected void destroyNode() {
         if (pipeline != null) {
             pipeline.destroyCopy(this);
+        } else {
+            logger.info(
+                    VIRTUAL_MERKLE_STATS.getMarker(),
+                    "Destroying virtual root node at route {}, but its pipeline is null. It may happen during failed reconnect",
+                    getRoute());
+            closeDataSource();
         }
     }
 
@@ -953,15 +959,17 @@ public V remove(final K key) {
      */
     @Override
     public void onShutdown(final boolean immediately) {
-
         if (immediately) {
             // If immediate shutdown is required then let the hasher know it is being stopped. If shutdown
             // is not immediate, the hasher will eventually stop once it finishes all of its work.
             hasher.shutdown();
         }
+        closeDataSource();
+    }
 
-        // We can now try to shut down the data source. If this doesn't shut things down, then there
-        // isn't much we can do aside from logging the fact. The node may well die before too long.
+    private void closeDataSource() {
+        // Shut down the data source. If this doesn't shut things down, then there isn't
+        // much we can do aside from logging the fact. The node may well die before too long
         if (dataSource != null) {
             try {
                 dataSource.close();