HDFS-10994. Support an XOR policy XOR-2-1-64k in HDFS. Contributed by Sammi Chen

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/ErasureCodeConstants.java

@@ -38,4 +38,7 @@ public final class ErasureCodeConstants {
 
   public static final ECSchema RS_6_3_LEGACY_SCHEMA = new ECSchema(
       RS_LEGACY_CODEC_NAME, 6, 3);
+
+  public static final ECSchema XOR_2_1_SCHEMA = new ECSchema(
+      XOR_CODEC_NAME, 2, 1);
 }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/HdfsConstants.java

@@ -147,6 +147,7 @@ public final class HdfsConstants {
   public static final byte RS_6_3_POLICY_ID = 0;
   public static final byte RS_3_2_POLICY_ID = 1;
   public static final byte RS_6_3_LEGACY_POLICY_ID = 2;
+  public static final byte XOR_2_1_POLICY_ID = 3;
 
   /* Hidden constructor */
   protected HdfsConstants() {

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

@@ -36,7 +36,7 @@ import java.util.TreeMap;
 public final class ErasureCodingPolicyManager {
 
   /**
-   * TODO: HDFS-8095
+   * TODO: HDFS-8095.
    */
   private static final int DEFAULT_CELLSIZE = 64 * 1024;
   private static final ErasureCodingPolicy SYS_POLICY1 =
@@ -48,10 +48,14 @@ public final class ErasureCodingPolicyManager {
   private static final ErasureCodingPolicy SYS_POLICY3 =
       new ErasureCodingPolicy(ErasureCodeConstants.RS_6_3_LEGACY_SCHEMA,
           DEFAULT_CELLSIZE, HdfsConstants.RS_6_3_LEGACY_POLICY_ID);
+  private static final ErasureCodingPolicy SYS_POLICY4 =
+      new ErasureCodingPolicy(ErasureCodeConstants.XOR_2_1_SCHEMA,
+          DEFAULT_CELLSIZE, HdfsConstants.XOR_2_1_POLICY_ID);
 
   //We may add more later.
   private static final ErasureCodingPolicy[] SYS_POLICIES =
-      new ErasureCodingPolicy[]{SYS_POLICY1, SYS_POLICY2, SYS_POLICY3};
+      new ErasureCodingPolicy[]{SYS_POLICY1, SYS_POLICY2, SYS_POLICY3,
+          SYS_POLICY4};
 
   // Supported storage policies for striped EC files
   private static final byte[] SUITABLE_STORAGE_POLICIES_FOR_EC_STRIPED_MODE = new byte[] {
@@ -96,6 +100,19 @@ public final class ErasureCodingPolicyManager {
     return SYS_POLICY1;
   }
 
+  /**
+   * Get system-wide policy by policy ID.
+   * @return ecPolicy
+   */
+  public static ErasureCodingPolicy getPolicyByPolicyID(byte id) {
+    for (ErasureCodingPolicy policy : SYS_POLICIES) {
+      if (policy.getId() == id) {
+        return policy;
+      }
+    }
+    return null;
+  }
+
   /**
    * Get all policies that's available to use.
    * @return all policies
@@ -141,7 +158,7 @@ public final class ErasureCodingPolicyManager {
   }
 
   /**
-   * Clear and clean up
+   * Clear and clean up.
    */
   public void clear() {
     activePoliciesByName.clear();

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

@@ -455,9 +455,13 @@ public class INodeFile extends INodeWithAdditionalFields
     if(!isStriped()){
       return max;
     }
-    // TODO support more policies based on policyId
+
     ErasureCodingPolicy ecPolicy =
-        ErasureCodingPolicyManager.getSystemDefaultPolicy();
+        ErasureCodingPolicyManager.getPolicyByPolicyID(
+            getErasureCodingPolicyID());
+    if (ecPolicy == null){
+      ecPolicy = ErasureCodingPolicyManager.getSystemDefaultPolicy();
+    }
     return (short) (ecPolicy.getNumDataUnits() + ecPolicy.getNumParityUnits());
   }
 

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

@@ -1888,21 +1888,41 @@ public class DFSTestUtil {
    * Creates the metadata of a file in striped layout. This method only
    * manipulates the NameNode state without injecting data to DataNode.
    * You should disable periodical heartbeat before use this.
-   *  @param file Path of the file to create
+   * @param file Path of the file to create
    * @param dir Parent path of the file
    * @param numBlocks Number of striped block groups to add to the file
    * @param numStripesPerBlk Number of striped cells in each block
    * @param toMkdir
    */
-  public static void createStripedFile(MiniDFSCluster cluster, Path file, Path dir,
-      int numBlocks, int numStripesPerBlk, boolean toMkdir) throws Exception {
+  public static void createStripedFile(MiniDFSCluster cluster, Path file,
+      Path dir, int numBlocks, int numStripesPerBlk, boolean toMkdir)
+      throws Exception {
+    createStripedFile(cluster, file, dir, numBlocks, numStripesPerBlk,
+        toMkdir, null);
+  }
+
+  /**
+   * Creates the metadata of a file in striped layout. This method only
+   * manipulates the NameNode state without injecting data to DataNode.
+   * You should disable periodical heartbeat before use this.
+   * @param file Path of the file to create
+   * @param dir Parent path of the file
+   * @param numBlocks Number of striped block groups to add to the file
+   * @param numStripesPerBlk Number of striped cells in each block
+   * @param toMkdir
+   * @param ecPolicy erasure coding policy apply to created file. A null value
+   *                 means using default erasure coding policy.
+   */
+  public static void createStripedFile(MiniDFSCluster cluster, Path file,
+      Path dir, int numBlocks, int numStripesPerBlk, boolean toMkdir,
+      ErasureCodingPolicy ecPolicy) throws Exception {
     DistributedFileSystem dfs = cluster.getFileSystem();
     // If outer test already set EC policy, dir should be left as null
     if (toMkdir) {
       assert dir != null;
       dfs.mkdirs(dir);
       try {
-        dfs.getClient().setErasureCodingPolicy(dir.toString(), null);
+        dfs.getClient().setErasureCodingPolicy(dir.toString(), ecPolicy);
       } catch (IOException e) {
         if (!e.getMessage().contains("non-empty directory")) {
           throw e;

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

@@ -64,20 +64,34 @@ public class TestDFSStripedInputStream {
   private DistributedFileSystem fs;
   private final Path dirPath = new Path("/striped");
   private Path filePath = new Path(dirPath, "file");
-  private final ErasureCodingPolicy ecPolicy =
-      ErasureCodingPolicyManager.getSystemDefaultPolicy();
-  private final short dataBlocks = (short) ecPolicy.getNumDataUnits();
-  private final short parityBlocks = (short) ecPolicy.getNumParityUnits();
-  private final int cellSize = ecPolicy.getCellSize();
+  private ErasureCodingPolicy ecPolicy;
+  private short dataBlocks;
+  private short parityBlocks;
+  private int cellSize;
   private final int stripesPerBlock = 2;
-  private final int blockSize = stripesPerBlock * cellSize;
-  private final int blockGroupSize =  dataBlocks * blockSize;
+  private int blockSize;
+  private int blockGroupSize;
 
   @Rule
   public Timeout globalTimeout = new Timeout(300000);
 
+  public ErasureCodingPolicy getEcPolicy() {
+    return ErasureCodingPolicyManager.getSystemDefaultPolicy();
+  }
+
   @Before
   public void setup() throws IOException {
+    /*
+     * Initialize erasure coding policy.
+     */
+    ecPolicy = getEcPolicy();
+    dataBlocks = (short) ecPolicy.getNumDataUnits();
+    parityBlocks = (short) ecPolicy.getNumParityUnits();
+    cellSize = ecPolicy.getCellSize();
+    blockSize = stripesPerBlock * cellSize;
+    blockGroupSize =  dataBlocks * blockSize;
+    System.out.println("EC policy = " + ecPolicy);
+
     conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, blockSize);
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_REPLICATION_MAX_STREAMS_KEY, 0);
     if (ErasureCodeNative.isNativeCodeLoaded()) {
@@ -94,7 +108,7 @@ public class TestDFSStripedInputStream {
     }
     fs = cluster.getFileSystem();
     fs.mkdirs(dirPath);
-    fs.getClient().setErasureCodingPolicy(dirPath.toString(), null);
+    fs.getClient().setErasureCodingPolicy(dirPath.toString(), ecPolicy);
   }
 
   @After
@@ -106,13 +120,13 @@ public class TestDFSStripedInputStream {
   }
 
   /**
-   * Test {@link DFSStripedInputStream#getBlockAt(long)}
+   * Test {@link DFSStripedInputStream#getBlockAt(long)}.
    */
   @Test
   public void testRefreshBlock() throws Exception {
     final int numBlocks = 4;
     DFSTestUtil.createStripedFile(cluster, filePath, null, numBlocks,
-        stripesPerBlock, false);
+        stripesPerBlock, false, ecPolicy);
     LocatedBlocks lbs = fs.getClient().namenode.getBlockLocations(
         filePath.toString(), 0, blockGroupSize * numBlocks);
     final DFSStripedInputStream in = new DFSStripedInputStream(fs.getClient(),
@@ -136,7 +150,7 @@ public class TestDFSStripedInputStream {
   public void testPread() throws Exception {
     final int numBlocks = 2;
     DFSTestUtil.createStripedFile(cluster, filePath, null, numBlocks,
-        stripesPerBlock, false);
+        stripesPerBlock, false, ecPolicy);
     LocatedBlocks lbs = fs.getClient().namenode.getBlockLocations(
         filePath.toString(), 0, blockGroupSize * numBlocks);
     int fileLen = blockGroupSize * numBlocks;
@@ -154,7 +168,9 @@ public class TestDFSStripedInputStream {
             bg.getBlock().getBlockPoolId());
       }
 
-      /** A variation of {@link DFSTestUtil#fillExpectedBuf} for striped blocks */
+      /**
+       * A variation of {@link DFSTestUtil#fillExpectedBuf} for striped blocks
+       */
       for (int i = 0; i < stripesPerBlock; i++) {
         for (int j = 0; j < dataBlocks; j++) {
           for (int k = 0; k < cellSize; k++) {
@@ -194,7 +210,7 @@ public class TestDFSStripedInputStream {
     final int numBlocks = 4;
     final int failedDNIdx = dataBlocks - 1;
     DFSTestUtil.createStripedFile(cluster, filePath, null, numBlocks,
-        stripesPerBlock, false);
+        stripesPerBlock, false, ecPolicy);
     LocatedBlocks lbs = fs.getClient().namenode.getBlockLocations(
         filePath.toString(), 0, blockGroupSize);
 
@@ -305,7 +321,7 @@ public class TestDFSStripedInputStream {
       setup();
     }
     DFSTestUtil.createStripedFile(cluster, filePath, null, numBlocks,
-        stripesPerBlock, false);
+        stripesPerBlock, false, ecPolicy);
     LocatedBlocks lbs = fs.getClient().namenode.
         getBlockLocations(filePath.toString(), 0, fileSize);
 
@@ -330,7 +346,9 @@ public class TestDFSStripedInputStream {
     byte[] expected = new byte[fileSize];
 
     for (LocatedBlock bg : lbs.getLocatedBlocks()) {
-      /** A variation of {@link DFSTestUtil#fillExpectedBuf} for striped blocks */
+      /**
+       * A variation of {@link DFSTestUtil#fillExpectedBuf} for striped blocks
+       */
       for (int i = 0; i < stripesPerBlock; i++) {
         for (int j = 0; j < dataBlocks; j++) {
           for (int k = 0; k < cellSize; k++) {
@@ -371,7 +389,7 @@ public class TestDFSStripedInputStream {
     final int numBlocks = 4;
     final int failedDNIdx = dataBlocks - 1;
     DFSTestUtil.createStripedFile(cluster, filePath, null, numBlocks,
-        stripesPerBlock, false);
+        stripesPerBlock, false, ecPolicy);
     LocatedBlocks lbs = fs.getClient().namenode.getBlockLocations(
         filePath.toString(), 0, blockGroupSize);
 

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

@@ -47,23 +47,36 @@ public class TestDFSStripedOutputStream {
     GenericTestUtils.setLogLevel(DataStreamer.LOG, Level.ALL);
   }
 
-  private final ErasureCodingPolicy ecPolicy =
-      ErasureCodingPolicyManager.getSystemDefaultPolicy();
-  private final int dataBlocks = ecPolicy.getNumDataUnits();
-  private final int parityBlocks = ecPolicy.getNumParityUnits();
+  private ErasureCodingPolicy ecPolicy;
+  private int dataBlocks;
+  private int parityBlocks;
 
   private MiniDFSCluster cluster;
   private DistributedFileSystem fs;
   private Configuration conf;
-  private final int cellSize = ecPolicy.getCellSize();
+  private int cellSize;
   private final int stripesPerBlock = 4;
-  private final int blockSize = cellSize * stripesPerBlock;
+  private int blockSize;
 
   @Rule
   public Timeout globalTimeout = new Timeout(300000);
 
+  public ErasureCodingPolicy getEcPolicy() {
+    return ErasureCodingPolicyManager.getSystemDefaultPolicy();
+  }
+
   @Before
   public void setup() throws IOException {
+    /*
+     * Initialize erasure coding policy.
+     */
+    ecPolicy = getEcPolicy();
+    dataBlocks = (short) ecPolicy.getNumDataUnits();
+    parityBlocks = (short) ecPolicy.getNumParityUnits();
+    cellSize = ecPolicy.getCellSize();
+    blockSize = stripesPerBlock * cellSize;
+    System.out.println("EC policy = " + ecPolicy);
+
     int numDNs = dataBlocks + parityBlocks + 2;
     conf = new Configuration();
     conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, blockSize);
@@ -76,7 +89,7 @@ public class TestDFSStripedOutputStream {
           NativeRSRawErasureCoderFactory.class.getCanonicalName());
     }
     cluster = new MiniDFSCluster.Builder(conf).numDataNodes(numDNs).build();
-    cluster.getFileSystem().getClient().setErasureCodingPolicy("/", null);
+    cluster.getFileSystem().getClient().setErasureCodingPolicy("/", ecPolicy);
     fs = cluster.getFileSystem();
   }
 

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

@@ -47,6 +47,7 @@ import org.apache.hadoop.util.StringUtils;
 import org.apache.log4j.Level;
 import org.junit.Assert;
 import org.junit.Assume;
+import org.junit.Before;
 import org.junit.Test;
 
 import java.io.IOException;
@@ -76,18 +77,36 @@ public class TestDFSStripedOutputStreamWithFailure {
         .getLogger().setLevel(Level.ALL);
   }
 
-  private final ErasureCodingPolicy ecPolicy =
-      ErasureCodingPolicyManager.getSystemDefaultPolicy();
-  private final int dataBlocks = ecPolicy.getNumDataUnits();
-  private final int parityBlocks = ecPolicy.getNumParityUnits();
-  private final int cellSize = ecPolicy.getCellSize();
+  private ErasureCodingPolicy ecPolicy;
+  private int dataBlocks;
+  private int parityBlocks;
+  private int cellSize;
   private final int stripesPerBlock = 4;
-  private final int blockSize = cellSize * stripesPerBlock;
-  private final int blockGroupSize = blockSize * dataBlocks;
+  private int blockSize;
+  private int blockGroupSize;
 
   private static final int FLUSH_POS =
       9 * DFSConfigKeys.DFS_BYTES_PER_CHECKSUM_DEFAULT + 1;
 
+  public ErasureCodingPolicy getEcPolicy() {
+    return ErasureCodingPolicyManager.getSystemDefaultPolicy();
+  }
+
+  /*
+   * Initialize erasure coding policy.
+   */
+  @Before
+  public void init(){
+    ecPolicy = getEcPolicy();
+    dataBlocks = ecPolicy.getNumDataUnits();
+    parityBlocks = ecPolicy.getNumParityUnits();
+    cellSize = ecPolicy.getCellSize();
+    blockSize = cellSize * stripesPerBlock;
+    blockGroupSize = blockSize * dataBlocks;
+    dnIndexSuite = getDnIndexSuite();
+    lengths = newLengths();
+  }
+
   List<Integer> newLengths() {
     final List<Integer> lens = new ArrayList<>();
     lens.add(FLUSH_POS + 2);
@@ -104,7 +123,7 @@ public class TestDFSStripedOutputStreamWithFailure {
     return lens;
   }
 
-  private final int[][] dnIndexSuite = getDnIndexSuite();
+  private int[][] dnIndexSuite;
 
   private int[][] getDnIndexSuite() {
     final int maxNumLevel = 2;
@@ -167,7 +186,7 @@ public class TestDFSStripedOutputStreamWithFailure {
     return positions;
   }
 
-  private final List<Integer> lengths = newLengths();
+  private List<Integer> lengths;
 
   Integer getLength(int i) {
     return i >= 0 && i < lengths.size()? lengths.get(i): null;

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSXORStripedInputStream.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;
+import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicy;
+import org.apache.hadoop.hdfs.protocol.HdfsConstants;
+import org.apache.hadoop.hdfs.server.namenode.ErasureCodingPolicyManager;
+
+/**
+ * This tests read operation of DFS striped file with XOR-2-1-64k erasure code
+ * policy.
+ */
+public class TestDFSXORStripedInputStream extends TestDFSStripedInputStream{
+
+  public ErasureCodingPolicy getEcPolicy() {
+    return ErasureCodingPolicyManager.getPolicyByPolicyID(
+        HdfsConstants.XOR_2_1_POLICY_ID);
+  }
+}

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

@@ -0,0 +1,35 @@
+/**
+ * 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;
+
+import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicy;
+import org.apache.hadoop.hdfs.protocol.HdfsConstants;
+import org.apache.hadoop.hdfs.server.namenode.ErasureCodingPolicyManager;
+
+/**
+ * This tests write operation of DFS striped file with XOR-2-1-64k erasure code
+ * policy.
+ */
+public class TestDFSXORStripedOutputStream extends TestDFSStripedOutputStream{
+
+  @Override
+  public ErasureCodingPolicy getEcPolicy() {
+    return ErasureCodingPolicyManager.getPolicyByPolicyID(
+        HdfsConstants.XOR_2_1_POLICY_ID);
+  }
+}

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

@@ -0,0 +1,36 @@
+/**
+ * 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;
+
+import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicy;
+import org.apache.hadoop.hdfs.protocol.HdfsConstants;
+import org.apache.hadoop.hdfs.server.namenode.ErasureCodingPolicyManager;
+
+/**
+ * This tests write operation of DFS striped file with XOR-2-1-64k erasure code
+ * policy when there is data node failure.
+ */
+public class TestDFSXORStripedOutputStreamWithFailure
+    extends TestDFSStripedOutputStreamWithFailure{
+
+  @Override
+  public ErasureCodingPolicy getEcPolicy() {
+    return ErasureCodingPolicyManager.getPolicyByPolicyID(
+        HdfsConstants.XOR_2_1_POLICY_ID);
+  }
+}