HDFS-16057. Make sure the order for location in ENTERING_MAINTENANCE state (#3084)

Reviewed-by: Wei-Chiu Chuang <weichiu@apache.org>
(cherry picked from commit 51ebf7b2a0e82d8bcd34867aea915c7838541fb7)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeManager.java

@@ -506,9 +506,8 @@ public class DatanodeManager {
   }
 
   private boolean isInactive(DatanodeInfo datanode) {
-    return datanode.isDecommissioned() ||
+    return datanode.isDecommissioned() || datanode.isEnteringMaintenance() ||
         (avoidStaleDataNodesForRead && datanode.isStale(staleInterval));
-
   }
   
   /**
@@ -572,8 +571,8 @@ public class DatanodeManager {
   }
 
   /**
-   * Move decommissioned/stale datanodes to the bottom. Also, sort nodes by
-   * network distance.
+   * Move decommissioned/entering_maintenance/stale datanodes to the bottom.
+   * Also, sort nodes by network distance.
    *
    * @param lb located block
    * @param targetHost target host
@@ -603,7 +602,7 @@ public class DatanodeManager {
     }
 
     DatanodeInfoWithStorage[] di = lb.getLocations();
-    // Move decommissioned/stale datanodes to the bottom
+    // Move decommissioned/entering_maintenance/stale datanodes to the bottom
     Arrays.sort(di, comparator);
 
     // Sort nodes by network distance only for located blocks

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestSortLocatedBlock.java

@@ -0,0 +1,142 @@
+/**
+ * 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.blockmanagement;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.DFSTestUtil;
+import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
+import org.apache.hadoop.hdfs.protocol.DatanodeInfoWithStorage;
+import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
+import org.apache.hadoop.hdfs.protocol.LocatedBlock;
+import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
+import org.apache.hadoop.util.Time;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.mockito.Mockito;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Date;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * This class tests the sorting of located blocks based on
+ * multiple states.
+ */
+public class TestSortLocatedBlock {
+  static final Logger LOG = LoggerFactory
+      .getLogger(TestSortLocatedBlock.class);
+
+  private static DatanodeManager dm;
+  private static final long STALE_INTERVAL = 30 * 1000 * 60;
+
+  @BeforeClass
+  public static void setup() throws IOException {
+    dm = mockDatanodeManager();
+  }
+
+  /**
+   * Test to verify sorting with multiple state
+   * datanodes exists in storage lists.
+   *
+   * We have the following list of datanodes, and create LocatedBlock.
+   * d0 - decommissioned
+   * d1 - entering_maintenance
+   * d2 - decommissioned
+   * d3 - stale
+   * d4 - live(in-service)
+   *
+   * After sorting the expected datanodes list will be:
+   * live -> stale -> entering_maintenance -> decommissioned,
+   * (d4 -> d3 -> d1 -> d0 -> d2)
+   * or
+   * (d4 -> d3 -> d1 -> d2 -> d0).
+   */
+  @Test(timeout = 30000)
+  public void testWithMultipleStateDatanodes() {
+    LOG.info("Starting test testWithMultipleStateDatanodes");
+    long blockID = Long.MIN_VALUE;
+    int totalDns = 5;
+    DatanodeInfo[] locs = new DatanodeInfo[totalDns];
+
+    // create datanodes
+    for (int i = 0; i < totalDns; i++) {
+      String ip = i + "." + i + "." + i + "." + i;
+      locs[i] = DFSTestUtil.getDatanodeInfo(ip);
+      locs[i].setLastUpdateMonotonic(Time.monotonicNow());
+    }
+
+    // set decommissioned state
+    locs[0].setDecommissioned();
+    locs[2].setDecommissioned();
+    ArrayList<DatanodeInfo> decommissionedNodes = new ArrayList<>();
+    decommissionedNodes.add(locs[0]);
+    decommissionedNodes.add(locs[2]);
+
+    // set entering_maintenance state
+    locs[1].startMaintenance();
+
+    // set stale state
+    locs[3].setLastUpdateMonotonic(Time.monotonicNow() -
+        DFSConfigKeys.DFS_NAMENODE_STALE_DATANODE_INTERVAL_DEFAULT * 1000 - 1);
+
+    ArrayList<LocatedBlock> locatedBlocks = new ArrayList<>();
+    locatedBlocks.add(new LocatedBlock(
+        new ExtendedBlock("pool", blockID,
+        1024L, new Date().getTime()), locs));
+
+    // sort located blocks
+    dm.sortLocatedBlocks(null, locatedBlocks);
+
+    // get locations after sorting
+    LocatedBlock locatedBlock = locatedBlocks.get(0);
+    DatanodeInfoWithStorage[] locations = locatedBlock.getLocations();
+
+    // assert location order:
+    // live -> stale -> entering_maintenance -> decommissioned
+    // live
+    assertEquals(locs[4].getIpAddr(), locations[0].getIpAddr());
+    // stale
+    assertEquals(locs[3].getIpAddr(), locations[1].getIpAddr());
+    // entering_maintenance
+    assertEquals(locs[1].getIpAddr(), locations[2].getIpAddr());
+    // decommissioned
+    assertEquals(true,
+        decommissionedNodes.contains(locations[3])
+        && decommissionedNodes.contains(locations[4]));
+  }
+
+  private static DatanodeManager mockDatanodeManager() throws IOException {
+    Configuration conf = new Configuration();
+    conf.setBoolean(
+        DFSConfigKeys.DFS_NAMENODE_AVOID_STALE_DATANODE_FOR_READ_KEY,
+        true);
+    conf.setLong(DFSConfigKeys.DFS_NAMENODE_STALE_DATANODE_INTERVAL_KEY,
+        STALE_INTERVAL);
+    FSNamesystem fsn = Mockito.mock(FSNamesystem.class);
+    BlockManager bm = Mockito.mock(BlockManager.class);
+    BlockReportLeaseManager blm = new BlockReportLeaseManager(conf);
+    Mockito.when(bm.getBlockReportLeaseManager()).thenReturn(blm);
+    return new DatanodeManager(bm, fsn, conf);
+  }
+}