HDFS-16732. [SBN READ] Avoid get location from observer when the bloc…

…k report is delayed.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

@@ -103,6 +103,7 @@
 import org.apache.commons.text.CaseUtils;
 import org.apache.hadoop.hdfs.protocol.ECTopologyVerifierResult;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
+import org.apache.hadoop.hdfs.protocol.HdfsLocatedFileStatus;
 import org.apache.hadoop.hdfs.protocol.SnapshotStatus;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_STORAGE_POLICY_ENABLED_KEY;
 import static org.apache.hadoop.hdfs.server.namenode.FSDirStatAndListingOp.*;
@@ -3470,6 +3471,16 @@ HdfsFileStatus getFileInfo(final String src, boolean resolveLink,
       logAuditEvent(false, operationName, src);
       throw e;
     }
+    if (needLocation && haEnabled && haContext != null &&
+        haContext.getState().getServiceState() == OBSERVER &&
+        stat instanceof HdfsLocatedFileStatus) {
+      LocatedBlocks lbs = ((HdfsLocatedFileStatus) stat).getLocatedBlocks();
+      for (LocatedBlock b : lbs.getLocatedBlocks()) {
+        if (b.getLocations() == null || b.getLocations().length == 0) {
+          throw new ObserverRetryOnActiveException("Zero blocklocations for " + src);
+        }
+      }
+    }
     logAuditEvent(true, operationName, src);
     return stat;
   }
@@ -4175,6 +4186,20 @@ DirectoryListing getListing(String src, byte[] startAfter,
       logAuditEvent(false, operationName, src);
       throw e;
     }
+    if (needLocation && haEnabled && haContext != null &&
+        haContext.getState().getServiceState() == OBSERVER) {
+      for(HdfsFileStatus fs : dl.getPartialListing()) {
+        if (fs instanceof HdfsLocatedFileStatus) {
+          LocatedBlocks bs = ((HdfsLocatedFileStatus) fs).getLocatedBlocks();
+          for (LocatedBlock b : bs.getLocatedBlocks()) {
+            if (b.getLocations() == null || b.getLocations().length == 0) {
+              throw new ObserverRetryOnActiveException(
+                  "Zero blocklocations for " + fs.toString());
+            }
+          }
+        }
+      }
+    }
     logAuditEvent(true, operationName, src);
     return dl;
   }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestObserverNodeWhenReportDelay.java

@@ -0,0 +1,153 @@
+/**
+ * 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.namenode.ha;
+
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BLOCK_SIZE_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BYTES_PER_CHECKSUM_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_STATE_CONTEXT_ENABLED_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_REPLICATION_KEY;
+import static org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter.getServiceState;
+import static org.apache.hadoop.hdfs.server.namenode.ha.ObserverReadProxyProvider.OBSERVER_PROBE_RETRY_PERIOD_KEY;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.apache.commons.lang3.ArrayUtils;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.ha.HAServiceProtocol.HAServiceState;
+import org.apache.hadoop.hdfs.DistributedFileSystem;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.hdfs.protocol.DirectoryListing;
+import org.apache.hadoop.hdfs.protocol.HdfsLocatedFileStatus;
+import org.apache.hadoop.hdfs.protocol.LocatedBlock;
+import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
+import org.apache.hadoop.hdfs.qjournal.MiniQJMHACluster;
+import org.apache.hadoop.hdfs.server.datanode.DataNode;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class TestObserverNodeWhenReportDelay {
+  public static final Logger LOG =
+      LoggerFactory.getLogger(TestObserverNodeWhenReportDelay.class.getName());
+
+  private final static String CONTENT = "0123456789";
+  private final static Path TEST_PATH = new Path("/TestObserverNode");
+
+  private static Configuration conf;
+  private static MiniQJMHACluster qjmhaCluster;
+  private static MiniDFSCluster dfsCluster;
+  private static DistributedFileSystem dfs;
+
+  @BeforeClass
+  public static void startUpCluster() throws Exception {
+    conf = new Configuration();
+    conf.setBoolean(DFS_NAMENODE_STATE_CONTEXT_ENABLED_KEY, true);
+    conf.setInt(DFS_BLOCK_SIZE_KEY, 5);
+    conf.setInt(DFS_BYTES_PER_CHECKSUM_KEY, 5);
+    conf.setInt(DFS_REPLICATION_KEY, 1);
+    conf.setInt(OBSERVER_PROBE_RETRY_PERIOD_KEY, -1);
+    qjmhaCluster = HATestUtil.setUpObserverCluster(conf, 1, 2, true);
+    dfsCluster = qjmhaCluster.getDfsCluster();
+  }
+
+  @AfterClass
+  public static void shutDownCluster() throws IOException {
+    if (qjmhaCluster != null) {
+      qjmhaCluster.shutdown();
+    }
+  }
+
+  @Before
+  public void setUp() throws Exception {
+    dfs = HATestUtil.configureObserverReadFs(dfsCluster, conf, ObserverReadProxyProvider.class,
+        true);
+  }
+
+  @After
+  public void cleanUp() throws IOException {
+    dfs.delete(TEST_PATH, true);
+    assertEquals("NN[0] should be active", HAServiceState.ACTIVE,
+        getServiceState(dfsCluster.getNameNode(0)));
+    assertEquals("NN[1] should be standby", HAServiceState.STANDBY,
+        getServiceState(dfsCluster.getNameNode(1)));
+    assertEquals("NN[2] should be observer", HAServiceState.OBSERVER,
+        getServiceState(dfsCluster.getNameNode(2)));
+  }
+
+  @Test
+  public void testReadWriteWhenReportDelay() throws Exception {
+    // 1 Disable block report to observer.
+    for (DataNode dn : dfsCluster.getDataNodes()) {
+      Configuration conf = new Configuration(dn.getConf());
+      conf.set("dfs.ha.namenodes.ns1", "nn0,nn1");
+      dn.refreshNamenodes(conf);
+    }
+
+    // 2 Create File
+    FSDataOutputStream out = dfs.create(TEST_PATH);
+    out.write(CONTENT.getBytes());
+    out.close();
+    dfsCluster.rollEditLogAndTail(0);
+
+    // 3 Read file
+    //   The block report of observer is delayed, so failover to active
+    byte[] buf = new byte[CONTENT.length()];
+    FSDataInputStream in = dfs.open(TEST_PATH);
+    in.readFully(buf);
+    in.close();
+    Assert.assertEquals(CONTENT, new String(buf));
+    assertSentTo(0);
+
+    // 4 List path with location
+    //   the block report of observer is delayed, so failover to active.
+    DirectoryListing listing = dfs.getClient().listPaths("/", new byte[0], true);
+    assertSentTo(0);
+    Assert.assertEquals(1, listing.getPartialListing().length);
+    LocatedBlocks lbs =((HdfsLocatedFileStatus) listing.getPartialListing()[0]).getLocatedBlocks();
+    List<LocatedBlock> blocks = lbs.getLocatedBlocks();
+    Assert.assertEquals(2, blocks.size());
+    Assert.assertTrue(ArrayUtils.isNotEmpty(blocks.get(0).getLocations()));
+    Assert.assertTrue(ArrayUtils.isNotEmpty(blocks.get(1).getLocations()));
+
+    // 5 Get located file info with location
+    //   the block report of observer is delayed, so failover to active.
+    HdfsLocatedFileStatus status = dfs.getClient().getLocatedFileInfo(TEST_PATH.toString(), false);
+    assertSentTo(0);
+    blocks = status.getLocatedBlocks().getLocatedBlocks();
+    Assert.assertEquals(2, blocks.size());
+    Assert.assertTrue(ArrayUtils.isNotEmpty(blocks.get(0).getLocations()));
+    Assert.assertTrue(ArrayUtils.isNotEmpty(blocks.get(1).getLocations()));
+  }
+
+
+  private void assertSentTo(int nnIdx) throws IOException {
+    assertTrue("Request was not sent to the expected namenode " + nnIdx,
+        HATestUtil.isSentToAnyOfNameNodes(dfs, dfsCluster, nnIdx));
+  }
+}