HDFS-16724. RBF should support get the information about ancestor mount points (#4719)

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/NoLocationException.java

@@ -0,0 +1,33 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hdfs.server.federation.router;
+
+import java.io.IOException;
+
+/**
+ * This exception is thrown when can not get any mount point for the input path.
+ * RBF cannot forward any requests for the path.
+ */
+public class NoLocationException extends IOException {
+
+  private static final long serialVersionUID = 1L;
+
+  public NoLocationException(String path, Class<?> t) {
+    super("Cannot find locations for " + path + " in " + t.getSimpleName());
+  }
+}

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterClientProtocol.java

@@ -935,19 +935,22 @@ public class RouterClientProtocol implements ClientProtocol {
   public HdfsFileStatus getFileInfo(String src) throws IOException {
     rpcServer.checkOperation(NameNode.OperationCategory.READ);
 
-    final List<RemoteLocation> locations =
-        rpcServer.getLocationsForPath(src, false, false);
-    RemoteMethod method = new RemoteMethod("getFileInfo",
-        new Class<?>[] {String.class}, new RemoteParam());
-
     HdfsFileStatus ret = null;
-    // If it's a directory, we check in all locations
-    if (rpcServer.isPathAll(src)) {
-      ret = getFileInfoAll(locations, method);
-    } else {
-      // Check for file information sequentially
-      ret = rpcClient.invokeSequential(
-          locations, method, HdfsFileStatus.class, null);
+    IOException noLocationException = null;
+    try {
+      final List<RemoteLocation> locations = rpcServer.getLocationsForPath(src, false, false);
+      RemoteMethod method = new RemoteMethod("getFileInfo",
+          new Class<?>[] {String.class}, new RemoteParam());
+
+      // If it's a directory, we check in all locations
+      if (rpcServer.isPathAll(src)) {
+        ret = getFileInfoAll(locations, method);
+      } else {
+        // Check for file information sequentially
+        ret = rpcClient.invokeSequential(locations, method, HdfsFileStatus.class, null);
+      }
+    } catch (NoLocationException | RouterResolveException e) {
+      noLocationException = e;
     }
 
     // If there is no real path, check mount points
@@ -966,6 +969,12 @@ public class RouterClientProtocol implements ClientProtocol {
       }
     }
 
+    // Can't find mount point for path and the path didn't contain any sub monit points,
+    // throw the NoLocationException to client.
+    if (ret == null && noLocationException != null) {
+      throw noLocationException;
+    }
+
     return ret;
   }
 

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterRpcServer.java

@@ -1731,8 +1731,7 @@ public class RouterRpcServer extends AbstractService implements ClientProtocol,
       final PathLocation location =
           this.subclusterResolver.getDestinationForPath(path);
       if (location == null) {
-        throw new IOException("Cannot find locations for " + path + " in " +
-            this.subclusterResolver.getClass().getSimpleName());
+        throw new NoLocationException(path, this.subclusterResolver.getClass());
       }
 
       // We may block some write operations

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterMountTableWithoutDefaultNS.java

@@ -0,0 +1,147 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hdfs.server.federation.router;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.protocol.ClientProtocol;
+import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
+import org.apache.hadoop.hdfs.server.federation.MiniRouterDFSCluster.RouterContext;
+import org.apache.hadoop.hdfs.server.federation.RouterConfigBuilder;
+import org.apache.hadoop.hdfs.server.federation.StateStoreDFSCluster;
+import org.apache.hadoop.hdfs.server.federation.resolver.MountTableManager;
+import org.apache.hadoop.hdfs.server.federation.resolver.MountTableResolver;
+import org.apache.hadoop.hdfs.server.federation.resolver.RouterResolveException;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.AddMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.AddMountTableEntryResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetMountTableEntriesRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetMountTableEntriesResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.RemoveMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.records.MountTable;
+import org.apache.hadoop.test.LambdaTestUtils;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.util.Collections;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Test a router end-to-end including the MountTable without default nameservice.
+ */
+public class TestRouterMountTableWithoutDefaultNS {
+  private static StateStoreDFSCluster cluster;
+  private static RouterContext routerContext;
+  private static MountTableResolver mountTable;
+  private static ClientProtocol routerProtocol;
+
+  @BeforeClass
+  public static void globalSetUp() throws Exception {
+    // Build and start a federated cluster
+    cluster = new StateStoreDFSCluster(false, 2);
+    Configuration conf = new RouterConfigBuilder()
+        .stateStore()
+        .admin()
+        .rpc()
+        .build();
+    conf.setInt(RBFConfigKeys.DFS_ROUTER_ADMIN_MAX_COMPONENT_LENGTH_KEY, 20);
+    conf.setBoolean(RBFConfigKeys.DFS_ROUTER_DEFAULT_NAMESERVICE_ENABLE, false);
+    cluster.addRouterOverrides(conf);
+    cluster.startCluster();
+    cluster.startRouters();
+    cluster.waitClusterUp();
+
+    // Get the end points
+    routerContext = cluster.getRandomRouter();
+    Router router = routerContext.getRouter();
+    routerProtocol = routerContext.getClient().getNamenode();
+    mountTable = (MountTableResolver) router.getSubclusterResolver();
+  }
+
+  @AfterClass
+  public static void tearDown() {
+    if (cluster != null) {
+      cluster.stopRouter(routerContext);
+      cluster.shutdown();
+      cluster = null;
+    }
+  }
+
+  @After
+  public void clearMountTable() throws IOException {
+    RouterClient client = routerContext.getAdminClient();
+    MountTableManager mountTableManager = client.getMountTableManager();
+    GetMountTableEntriesRequest req1 = GetMountTableEntriesRequest.newInstance("/");
+    GetMountTableEntriesResponse response = mountTableManager.getMountTableEntries(req1);
+    for (MountTable entry : response.getEntries()) {
+      RemoveMountTableEntryRequest req2 =
+          RemoveMountTableEntryRequest.newInstance(entry.getSourcePath());
+      mountTableManager.removeMountTableEntry(req2);
+    }
+  }
+
+  /**
+   * Add a mount table entry to the mount table through the admin API.
+   * @param entry Mount table entry to add.
+   * @return If it was succesfully added.
+   * @throws IOException Problems adding entries.
+   */
+  private boolean addMountTable(final MountTable entry) throws IOException {
+    RouterClient client = routerContext.getAdminClient();
+    MountTableManager mountTableManager = client.getMountTableManager();
+    AddMountTableEntryRequest addRequest = AddMountTableEntryRequest.newInstance(entry);
+    AddMountTableEntryResponse addResponse = mountTableManager.addMountTableEntry(addRequest);
+
+    // Reload the Router cache
+    mountTable.loadCache(true);
+
+    return addResponse.getStatus();
+  }
+
+  /**
+   * Verify that RBF that disable default nameservice should support
+   * get information about ancestor mount points.
+   */
+  @Test
+  public void testGetFileInfoWithSubMountPoint() throws IOException {
+    MountTable addEntry = MountTable.newInstance("/testdir/1",
+        Collections.singletonMap("ns0", "/testdir/1"));
+    assertTrue(addMountTable(addEntry));
+    HdfsFileStatus finfo = routerProtocol.getFileInfo("/testdir");
+    assertNotNull(finfo);
+    assertEquals("supergroup", finfo.getGroup());
+    assertTrue(finfo.isDirectory());
+  }
+
+  /**
+   * Verify that RBF doesn't support get the file information
+   * with no location and sub mount points.
+   */
+  @Test
+  public void testGetFileInfoWithoutSubMountPoint() throws Exception {
+    MountTable addEntry = MountTable.newInstance("/testdir/1",
+        Collections.singletonMap("ns0", "/testdir/1"));
+    assertTrue(addMountTable(addEntry));
+    LambdaTestUtils.intercept(RouterResolveException.class,
+        () -> routerContext.getRouter().getRpcServer().getFileInfo("/testdir2"));
+  }
+}