HDFS-11412. Maintenance minimum replication config value allowable range should be [0, DefaultReplication]. (Manoj Govindassamy via mingma)

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

@@ -484,12 +484,12 @@ public class BlockManager implements BlockStatsMXBean {
           + DFSConfigKeys.DFS_NAMENODE_MAINTENANCE_REPLICATION_MIN_KEY
           + " = " + minMaintenanceR + " < 0");
     }
-    if (minMaintenanceR > minR) {
+    if (minMaintenanceR > defaultReplication) {
       throw new IOException("Unexpected configuration parameters: "
           + DFSConfigKeys.DFS_NAMENODE_MAINTENANCE_REPLICATION_MIN_KEY
           + " = " + minMaintenanceR + " > "
-          + DFSConfigKeys.DFS_NAMENODE_REPLICATION_MIN_KEY
+          + DFSConfigKeys.DFS_REPLICATION_KEY
-          + " = " + minR);
+          + " = " + defaultReplication);
     }
     this.minReplicationToBeInMaintenance = (short)minMaintenanceR;
 
@@ -825,7 +825,8 @@ public class BlockManager implements BlockStatsMXBean {
     if (block.isStriped()) {
       return ((BlockInfoStriped) block).getRealDataBlockNum();
     } else {
-      return minReplicationToBeInMaintenance;
+      return (short) Math.min(minReplicationToBeInMaintenance,
+          block.getReplication());
     }
   }
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/MiniDFSCluster.java

@@ -807,6 +807,14 @@ public class MiniDFSCluster implements AutoCloseable {
     
       int replication = conf.getInt(DFS_REPLICATION_KEY, 3);
       conf.setInt(DFS_REPLICATION_KEY, Math.min(replication, numDataNodes));
+      int maintenanceMinReplication = conf.getInt(
+          DFSConfigKeys.DFS_NAMENODE_MAINTENANCE_REPLICATION_MIN_KEY,
+          DFSConfigKeys.DFS_NAMENODE_MAINTENANCE_REPLICATION_MIN_DEFAULT);
+      if (maintenanceMinReplication ==
+          DFSConfigKeys.DFS_NAMENODE_MAINTENANCE_REPLICATION_MIN_DEFAULT) {
+        conf.setInt(DFSConfigKeys.DFS_NAMENODE_MAINTENANCE_REPLICATION_MIN_KEY,
+            Math.min(maintenanceMinReplication, numDataNodes));
+      }
       int safemodeExtension = conf.getInt(
           DFS_NAMENODE_SAFEMODE_EXTENSION_TESTING_KEY, 0);
       conf.setInt(DFS_NAMENODE_SAFEMODE_EXTENSION_KEY, safemodeExtension);

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestMaintenanceState.java

@@ -20,6 +20,7 @@ package org.apache.hadoop.hdfs;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -30,6 +31,7 @@ import java.util.List;
 import java.util.Map;
 
 import com.google.common.collect.Lists;
+import org.junit.Assert;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.apache.hadoop.fs.FileSystem;
@@ -66,6 +68,38 @@ public class TestMaintenanceState extends AdminStatesBaseTest {
         minMaintenanceR);
   }
 
+  /**
+   * Test valid value range for the config namenode.maintenance.replication.min.
+   */
+  @Test (timeout = 60000)
+  public void testMaintenanceMinReplConfigRange() {
+    LOG.info("Setting testMaintenanceMinReplConfigRange");
+
+    // Case 1: Maintenance min replication less allowed minimum 0
+    setMinMaintenanceR(-1);
+    try {
+      startCluster(1, 1);
+      fail("Cluster start should fail when 'dfs.namenode.maintenance" +
+          ".replication.min=-1'");
+    } catch (IOException e) {
+      LOG.info("Expected exception: " + e);
+    }
+
+    // Case 2: Maintenance min replication greater
+    // allowed max of DFSConfigKeys.DFS_REPLICATION_KEY
+    int defaultRepl = getConf().getInt(
+        DFSConfigKeys.DFS_REPLICATION_KEY,
+        DFSConfigKeys.DFS_REPLICATION_DEFAULT);
+    setMinMaintenanceR(defaultRepl + 1);
+    try {
+      startCluster(1, 1);
+      fail("Cluster start should fail when 'dfs.namenode.maintenance" +
+          ".replication.min > " + defaultRepl + "'");
+    } catch (IOException e) {
+      LOG.info("Expected exception: " + e);
+    }
+  }
+
   /**
    * Verify a node can transition from AdminStates.ENTERING_MAINTENANCE to
    * AdminStates.NORMAL.
@@ -406,6 +440,83 @@ public class TestMaintenanceState extends AdminStatesBaseTest {
     cleanupFile(fileSys, file);
   }
 
+  /**
+   * Test file block replication lesser than maintenance minimum.
+   */
+  @Test(timeout = 360000)
+  public void testFileBlockReplicationAffectingMaintenance()
+      throws Exception {
+    int defaultReplication = getConf().getInt(DFSConfigKeys
+        .DFS_REPLICATION_KEY, DFSConfigKeys.DFS_REPLICATION_DEFAULT);
+    int defaultMaintenanceMinRepl = getConf().getInt(DFSConfigKeys
+        .DFS_NAMENODE_MAINTENANCE_REPLICATION_MIN_KEY,
+        DFSConfigKeys.DFS_NAMENODE_MAINTENANCE_REPLICATION_MIN_DEFAULT);
+
+    // Case 1:
+    //  * Maintenance min larger than default min replication
+    //  * File block replication larger than maintenance min
+    //  * Initial data nodes not sufficient to remove all maintenance nodes
+    //    as file block replication is greater than maintenance min.
+    //  * Data nodes added later for the state transition to progress
+    int maintenanceMinRepl = defaultMaintenanceMinRepl + 1;
+    int fileBlockReplication = maintenanceMinRepl + 1;
+    int numAddedDataNodes = 1;
+    int numInitialDataNodes = (maintenanceMinRepl * 2 - numAddedDataNodes);
+    Assert.assertTrue(maintenanceMinRepl <= defaultReplication);
+    testFileBlockReplicationImpl(maintenanceMinRepl,
+        numInitialDataNodes, numAddedDataNodes, fileBlockReplication);
+
+    // Case 2:
+    //  * Maintenance min larger than default min replication
+    //  * File block replication lesser than maintenance min
+    //  * Initial data nodes after removal of maintenance nodes is still
+    //    sufficient for the file block replication.
+    //  * No new data nodes to be added, still the state transition happens
+    maintenanceMinRepl = defaultMaintenanceMinRepl + 1;
+    fileBlockReplication = maintenanceMinRepl - 1;
+    numAddedDataNodes = 0;
+    numInitialDataNodes = (maintenanceMinRepl * 2 - numAddedDataNodes);
+    testFileBlockReplicationImpl(maintenanceMinRepl,
+        numInitialDataNodes, numAddedDataNodes, fileBlockReplication);
+  }
+
+  private void testFileBlockReplicationImpl(
+      int maintenanceMinRepl, int numDataNodes, int numNewDataNodes,
+      int fileBlockRepl)
+      throws Exception {
+    setup();
+    LOG.info("Starting testLargerMinMaintenanceReplication - maintMinRepl: "
+        + maintenanceMinRepl + ", numDNs: " + numDataNodes + ", numNewDNs: "
+        + numNewDataNodes + ", fileRepl: " + fileBlockRepl);
+    LOG.info("Setting maintenance minimum replication: " + maintenanceMinRepl);
+    setMinMaintenanceR(maintenanceMinRepl);
+    startCluster(1, numDataNodes);
+
+    final Path file = new Path("/testLargerMinMaintenanceReplication.dat");
+
+    FileSystem fileSys = getCluster().getFileSystem(0);
+    writeFile(fileSys, file, fileBlockRepl, 1);
+    final DatanodeInfo[] nodes = getFirstBlockReplicasDatanodeInfos(fileSys,
+        file);
+
+    ArrayList<String> nodeUuids = new ArrayList<>();
+    for (int i = 0; i < maintenanceMinRepl && i < nodes.length; i++) {
+      nodeUuids.add(nodes[i].getDatanodeUuid());
+    }
+
+    List<DatanodeInfo> maintenanceDNs = takeNodeOutofService(0, nodeUuids,
+        Long.MAX_VALUE, null, null, AdminStates.ENTERING_MAINTENANCE);
+
+    for (int i = 0; i < numNewDataNodes; i++) {
+      getCluster().startDataNodes(getConf(), 1, true, null, null);
+    }
+    getCluster().waitActive();
+    refreshNodes(0);
+    waitNodeState(maintenanceDNs, AdminStates.IN_MAINTENANCE);
+    cleanupFile(fileSys, file);
+    teardown();
+  }
+
   /**
    * Transition from IN_MAINTENANCE to DECOMMISSIONED.
    */