HDFS-17788. [ARR] getFileInfo not handle exception rightly which may cause FileNotFoundException in DistributedFileSystem. (#7703). Contributed by hfutatzhanghb.

Reviewed-by: He Xiaoqiao <hexiaoqiao@apache.org>
Reviewed-by: Shilun Fan <slfan1989@apache.org>
Signed-off-by: Jian Zhang <keepromise@apache.org>

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

@@ -579,6 +579,8 @@ public class RouterAsyncClientProtocol extends RouterClientProtocol {
       if (e instanceof NoLocationException
           || e instanceof RouterResolveException) {
         noLocationException[0] = e;
+      } else {
+        throw e;
       }
       return null;
     }, IOException.class);

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

@@ -0,0 +1,81 @@
+/**
+ * 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.async;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.DFSClient;
+import org.apache.hadoop.hdfs.protocol.DirectoryListing;
+import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
+import org.apache.hadoop.hdfs.server.federation.RouterConfigBuilder;
+import org.apache.hadoop.hdfs.server.federation.StateStoreDFSCluster;
+import org.apache.hadoop.hdfs.server.federation.router.RBFConfigKeys;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.net.URI;
+
+import static org.apache.hadoop.hdfs.server.federation.FederationTestUtils.transitionClusterNSToActive;
+import static org.apache.hadoop.hdfs.server.federation.FederationTestUtils.transitionClusterNSToStandby;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+public class TestRouterAsyncRpcWhenNamenodeFailover {
+
+  private StateStoreDFSCluster cluster;
+
+  private void setupCluster(boolean ha)
+      throws Exception {
+    // Build and start a federated cluster.
+    cluster = new StateStoreDFSCluster(ha, 2);
+    Configuration routerConf = new RouterConfigBuilder()
+        .stateStore()
+        .metrics()
+        .admin()
+        .rpc()
+        .heartbeat()
+        .build();
+
+    routerConf.setBoolean(RBFConfigKeys.DFS_ROUTER_ASYNC_RPC_ENABLE_KEY, true);
+
+    cluster.addRouterOverrides(routerConf);
+    cluster.startCluster();
+    cluster.startRouters();
+    cluster.waitClusterUp();
+  }
+
+  @Test
+  public void testGetFileInfoWhenNsFailover() throws Exception {
+    setupCluster(true);
+    Configuration conf = cluster.getRouterClientConf();
+    conf.setInt("dfs.client.retry.max.attempts", 2);
+    DFSClient routerClient = new DFSClient(new URI("hdfs://fed"), conf);
+    transitionClusterNSToActive(cluster, 0);
+
+    String basePath = "/ARR/testGetFileInfo";
+    routerClient.mkdirs(basePath);
+    DirectoryListing directoryListing = routerClient.listPaths("/ARR", new byte[0]);
+    assertEquals(1, directoryListing.getPartialListing().length);
+
+    transitionClusterNSToStandby(cluster);
+
+    assertThrows(IOException.class, () -> {
+      HdfsFileStatus fileInfo = routerClient.getFileInfo(basePath + 1);
+    });
+  }
+}
+