HDFS-11643. Add shouldReplicate option to create builder. Contributed by SammiChen.

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/CreateFlag.java

@@ -110,7 +110,13 @@ public enum CreateFlag {
    * 'local' means the same host as the client is being run on.
    */
   @InterfaceAudience.LimitedPrivate({"HBase"})
-  NO_LOCAL_WRITE((short) 0x40);
+  NO_LOCAL_WRITE((short) 0x40),
+
+  /**
+   * Enforce the file to be a replicated file, no matter what its parent
+   * directory's replication or erasure coding policy is.
+   */
+  SHOULD_REPLICATE((short) 0x80);
 
   private final short mode;
 

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

@@ -100,6 +100,7 @@ import org.apache.hadoop.crypto.key.KeyProviderDelegationTokenExtension;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
+import org.apache.commons.lang.StringUtils;
 
 import javax.annotation.Nonnull;
 
@@ -462,17 +463,20 @@ public class DistributedFileSystem extends FileSystem {
   /**
    * Same as
    * {@link #create(Path, FsPermission, EnumSet<CreateFlag>, int, short, long,
-   * Progressable, ChecksumOpt)} with the addition of favoredNodes that is a
-   * hint to where the namenode should place the file blocks.
-   * The favored nodes hint is not persisted in HDFS. Hence it may be honored
-   * at the creation time only. And with favored nodes, blocks will be pinned
-   * on the datanodes to prevent balancing move the block. HDFS could move the
-   * blocks during replication, to move the blocks from favored nodes. A value
-   * of null means no favored nodes for this create.
-   * Another addition is ecPolicyName. A non-null ecPolicyName specifies an
+   * Progressable, ChecksumOpt)} with a few additions. First, addition of
+   * favoredNodes that is a hint to where the namenode should place the file
+   * blocks. The favored nodes hint is not persisted in HDFS. Hence it may be
+   * honored at the creation time only. And with favored nodes, blocks will be
+   * pinned on the datanodes to prevent balancing move the block. HDFS could
+   * move the blocks during replication, to move the blocks from favored nodes.
+   * A value of null means no favored nodes for this create.
+   * The second addition is ecPolicyName. A non-null ecPolicyName specifies an
    * explicit erasure coding policy for this file, overriding the inherited
-   * policy. A null ecPolicyName means the file will inherit its EC policy from
-   * an ancestor (the default).
+   * policy. A null ecPolicyName means the file will inherit its EC policy or
+   * replication policy from its ancestor (the default).
+   * ecPolicyName and SHOULD_REPLICATE CreateFlag are mutually exclusive. It's
+   * invalid to set both SHOULD_REPLICATE and a non-null ecPolicyName.
+   *
    */
   private HdfsDataOutputStream create(final Path f,
       final FsPermission permission, final EnumSet<CreateFlag> flag,
@@ -2669,6 +2673,7 @@ public class DistributedFileSystem extends FileSystem {
     private final DistributedFileSystem dfs;
     private InetSocketAddress[] favoredNodes = null;
     private String ecPolicyName = null;
+    private boolean shouldReplicate  = false;
 
     public HdfsDataOutputStreamBuilder(DistributedFileSystem dfs, Path path) {
       super(dfs, path);
@@ -2690,6 +2695,14 @@ public class DistributedFileSystem extends FileSystem {
       return ecPolicyName;
     }
 
+    /**
+     * Enforce the file to be a striped file with erasure coding policy
+     * 'policyName', no matter what its parent directory's replication
+     * or erasure coding policy is. Don't call this function and
+     * enforceReplicate() in the same builder since they have conflict
+     * of interest.
+     *
+     */
     public HdfsDataOutputStreamBuilder setEcPolicyName(
         @Nonnull final String policyName) {
       Preconditions.checkNotNull(policyName);
@@ -2697,9 +2710,33 @@ public class DistributedFileSystem extends FileSystem {
       return this;
     }
 
+    public boolean shouldReplicate() {
+      return shouldReplicate;
+    }
+
+    /**
+     * Enforce the file to be a replicated file, no matter what its parent
+     * directory's replication or erasure coding policy is. Don't call this
+     * function and setEcPolicyName() in the same builder since they have
+     * conflict of interest.
+     */
+    public HdfsDataOutputStreamBuilder replicate() {
+      shouldReplicate  = true;
+      return this;
+    }
+
     @Override
     public HdfsDataOutputStream build() throws IOException {
-      return dfs.create(getPath(), getPermission(), getFlags(),
+      Preconditions.checkState(
+          !(shouldReplicate() && (!StringUtils.isEmpty(getEcPolicyName()))),
+          "shouldReplicate and ecPolicyName are " +
+              "exclusive parameters. Set both is not allowed!");
+
+      EnumSet<CreateFlag> createFlags = getFlags();
+      if (shouldReplicate()) {
+        createFlags.add(CreateFlag.SHOULD_REPLICATE);
+      }
+      return dfs.create(getPath(), getPermission(), createFlags,
           getBufferSize(), getReplication(), getBlockSize(),
           getProgress(), getChecksumOpt(), getFavoredNodes(),
           getEcPolicyName());

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

@@ -154,8 +154,10 @@ public interface ClientProtocol {
    * @param src path of the file being created.
    * @param masked masked permission.
    * @param clientName name of the current client.
-   * @param flag indicates whether the file should be
-   * overwritten if it already exists or create if it does not exist or append.
+   * @param flag indicates whether the file should be overwritten if it already
+   *             exists or create if it does not exist or append, or whether the
+   *             file should be a replicate file, no matter what its ancestor's
+   *             replication or erasure coding policy is.
    * @param createParent create missing parent directory if true
    * @param replication block replication factor.
    * @param blockSize maximum block size.
@@ -163,7 +165,9 @@ public interface ClientProtocol {
    * @param ecPolicyName the name of erasure coding policy. A null value means
    *                     this file will inherit its parent directory's policy,
    *                     either traditional replication or erasure coding
-   *                     policy.
+   *                     policy. ecPolicyName and SHOULD_REPLICATE CreateFlag
+   *                     are mutually exclusive. It's invalid to set both
+   *                     SHOULD_REPLICATE flag and a non-null ecPolicyName.
    *
    * @return the status of the created file, it could be null if the server
    *           doesn't support returning the file status

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelperClient.java

@@ -1753,6 +1753,9 @@ public class PBHelperClient {
     if (flag.contains(CreateFlag.NEW_BLOCK)) {
       value |= CreateFlagProto.NEW_BLOCK.getNumber();
     }
+    if (flag.contains(CreateFlag.SHOULD_REPLICATE)) {
+      value |= CreateFlagProto.SHOULD_REPLICATE.getNumber();
+    }
     return value;
   }
 
@@ -1966,6 +1969,10 @@ public class PBHelperClient {
         == CreateFlagProto.NEW_BLOCK_VALUE) {
       result.add(CreateFlag.NEW_BLOCK);
     }
+    if ((flag & CreateFlagProto.SHOULD_REPLICATE.getNumber())
+        == CreateFlagProto.SHOULD_REPLICATE.getNumber()) {
+      result.add(CreateFlag.SHOULD_REPLICATE);
+    }
     return new EnumSetWritable<>(result, CreateFlag.class);
   }
 

hadoop-hdfs-project/hadoop-hdfs-client/src/main/proto/ClientNamenodeProtocol.proto

@@ -68,6 +68,7 @@ enum CreateFlagProto {
   APPEND = 0x04;    // Append to a file
   LAZY_PERSIST = 0x10; // File with reduced durability guarantees.
   NEW_BLOCK = 0x20; // Write data to a new block when appending
+  SHOULD_REPLICATE = 0x80; // Enforce to create a replicate file
 }
 
 message CreateRequestProto {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/balancer/NameNodeConnector.java

@@ -25,15 +25,18 @@ import java.net.URI;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.EnumSet;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicLong;
 
+import com.google.common.base.Preconditions;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.CreateFlag;
 import org.apache.hadoop.fs.FSDataOutputStream;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.FsServerDefaults;
@@ -241,7 +244,15 @@ public class NameNodeConnector implements Closeable {
         IOUtils.closeStream(fs.append(idPath));
         fs.delete(idPath, true);
       }
-      final FSDataOutputStream fsout = fs.create(idPath, false);
+
+      final FSDataOutputStream fsout = fs.newFSDataOutputStreamBuilder(idPath)
+          .replicate()
+          .setFlags(EnumSet.of(CreateFlag.CREATE))
+          .build();
+
+      Preconditions.checkState(!fs.getFileStatus(idPath).isErasureCoded(),
+          "Id File should be a replicate file");
+
       // mark balancer idPath to be deleted during filesystem closure
       fs.deleteOnExit(idPath);
       if (write2IdFile) {

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

@@ -352,7 +352,7 @@ class FSDirWriteFileOp {
       EnumSet<CreateFlag> flag, boolean createParent,
       short replication, long blockSize,
       FileEncryptionInfo feInfo, INode.BlocksMapUpdateInfo toRemoveBlocks,
-      String ecPolicyName, boolean logRetryEntry)
+      boolean shouldReplicate, String ecPolicyName, boolean logRetryEntry)
       throws IOException {
     assert fsn.hasWriteLock();
     boolean overwrite = flag.contains(CreateFlag.OVERWRITE);
@@ -386,7 +386,8 @@ class FSDirWriteFileOp {
         FSDirMkdirOp.createAncestorDirectories(fsd, iip, permissions);
     if (parent != null) {
       iip = addFile(fsd, parent, iip.getLastLocalName(), permissions,
-          replication, blockSize, holder, clientMachine, ecPolicyName);
+          replication, blockSize, holder, clientMachine, shouldReplicate,
+          ecPolicyName);
       newNode = iip != null ? iip.getLastINode().asFile() : null;
     }
     if (newNode == null) {
@@ -522,8 +523,8 @@ class FSDirWriteFileOp {
   private static INodesInPath addFile(
       FSDirectory fsd, INodesInPath existing, byte[] localName,
       PermissionStatus permissions, short replication, long preferredBlockSize,
-      String clientName, String clientMachine, String ecPolicyName)
-      throws IOException {
+      String clientName, String clientMachine, boolean shouldReplicate,
+      String ecPolicyName) throws IOException {
 
     Preconditions.checkNotNull(existing);
     long modTime = now();
@@ -531,16 +532,18 @@ class FSDirWriteFileOp {
     fsd.writeLock();
     try {
       boolean isStriped = false;
-      ErasureCodingPolicy ecPolicy;
-      if (!StringUtils.isEmpty(ecPolicyName)) {
-        ecPolicy = FSDirErasureCodingOp.getErasureCodingPolicyByName(
-            fsd.getFSNamesystem(), ecPolicyName);
-      } else {
-        ecPolicy = FSDirErasureCodingOp.unprotectedGetErasureCodingPolicy(
-            fsd.getFSNamesystem(), existing);
-      }
-      if (ecPolicy != null) {
-        isStriped = true;
+      ErasureCodingPolicy ecPolicy = null;
+      if (!shouldReplicate) {
+        if (!StringUtils.isEmpty(ecPolicyName)) {
+          ecPolicy = FSDirErasureCodingOp.getErasureCodingPolicyByName(
+              fsd.getFSNamesystem(), ecPolicyName);
+        } else {
+          ecPolicy = FSDirErasureCodingOp.unprotectedGetErasureCodingPolicy(
+              fsd.getFSNamesystem(), existing);
+        }
+        if (ecPolicy != null) {
+          isStriped = true;
+        }
       }
       final BlockType blockType = isStriped ?
           BlockType.STRIPED : BlockType.CONTIGUOUS;

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

@@ -2225,6 +2225,13 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
       throw new InvalidPathException(src);
     }
 
+    boolean shouldReplicate = flag.contains(CreateFlag.SHOULD_REPLICATE);
+    if (shouldReplicate &&
+        (!org.apache.commons.lang.StringUtils.isEmpty(ecPolicyName))) {
+      throw new HadoopIllegalArgumentException("SHOULD_REPLICATE flag and " +
+          "ecPolicyName are exclusive parameters. Set both is not allowed!");
+    }
+
     FSPermissionChecker pc = getPermissionChecker();
     INodesInPath iip = null;
     boolean skipSync = true; // until we do something that might create edits
@@ -2240,7 +2247,9 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
       iip = FSDirWriteFileOp.resolvePathForStartFile(
           dir, pc, src, flag, createParent);
 
-      if (!FSDirErasureCodingOp.hasErasureCodingPolicy(this, iip)) {
+      if (shouldReplicate ||
+          (org.apache.commons.lang.StringUtils.isEmpty(ecPolicyName) &&
+          !FSDirErasureCodingOp.hasErasureCodingPolicy(this, iip))) {
         blockManager.verifyReplication(src, replication, clientMachine);
       }
 
@@ -2272,7 +2281,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
       try {
         stat = FSDirWriteFileOp.startFile(this, iip, permissions, holder,
             clientMachine, flag, createParent, replication, blockSize, feInfo,
-            toRemoveBlocks, ecPolicyName, logRetryCache);
+            toRemoveBlocks, shouldReplicate, ecPolicyName, logRetryCache);
       } catch (IOException e) {
         skipSync = e instanceof StandbyException;
         throw e;

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

@@ -19,6 +19,7 @@ package org.apache.hadoop.hdfs;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.CommonConfigurationKeys;
+import org.apache.hadoop.fs.CreateFlag;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.permission.FsPermission;
@@ -46,6 +47,7 @@ import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.security.PrivilegedExceptionAction;
 import java.util.Collection;
+import java.util.EnumSet;
 import java.util.List;
 
 import static org.apache.hadoop.test.GenericTestUtils.assertExceptionContains;
@@ -564,4 +566,60 @@ public class TestErasureCodingPolicies {
     assertEquals(ecPolicyOnDir, fs.getErasureCodingPolicy(dirPath));
     fs.delete(dirPath, true);
   }
+
+  /**
+   * Enforce file as replicated file without regarding its parent's EC policy.
+   */
+  @Test
+  public void testEnforceAsReplicatedFile() throws Exception {
+    final Path dirPath = new Path("/striped");
+    final Path filePath = new Path(dirPath, "file");
+
+    fs.mkdirs(dirPath);
+    fs.setErasureCodingPolicy(dirPath, EC_POLICY.getName());
+
+    final String ecPolicyName = "RS-10-4-64k";
+    fs.newFSDataOutputStreamBuilder(filePath).build().close();
+    assertEquals(EC_POLICY, fs.getErasureCodingPolicy(filePath));
+    fs.delete(filePath, true);
+
+    fs.newFSDataOutputStreamBuilder(filePath)
+        .setEcPolicyName(ecPolicyName)
+        .build()
+        .close();
+    assertEquals(ecPolicyName, fs.getErasureCodingPolicy(filePath).getName());
+    fs.delete(filePath, true);
+
+    try {
+      fs.newFSDataOutputStreamBuilder(filePath)
+          .setEcPolicyName(ecPolicyName)
+          .replicate()
+          .build().close();
+      Assert.fail("shouldReplicate and ecPolicyName are exclusive " +
+          "parameters. Set both is not allowed.");
+    }catch (Exception e){
+      GenericTestUtils.assertExceptionContains("shouldReplicate and " +
+          "ecPolicyName are exclusive parameters. Set both is not allowed!", e);
+    }
+
+    try {
+      final DFSClient dfsClient = fs.getClient();
+      dfsClient.create(filePath.toString(), null,
+          EnumSet.of(CreateFlag.CREATE, CreateFlag.OVERWRITE,
+              CreateFlag.SHOULD_REPLICATE), false, (short) 1, 1024, null, 1024,
+          null, null, ecPolicyName);
+      Assert.fail("SHOULD_REPLICATE flag and ecPolicyName are exclusive " +
+          "parameters. Set both is not allowed.");
+    }catch (Exception e){
+      GenericTestUtils.assertExceptionContains("SHOULD_REPLICATE flag and " +
+          "ecPolicyName are exclusive parameters. Set both is not allowed!", e);
+    }
+
+    fs.newFSDataOutputStreamBuilder(filePath)
+        .replicate()
+        .build()
+        .close();
+    assertNull(fs.getErasureCodingPolicy(filePath));
+    fs.delete(dirPath, true);
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/balancer/TestBalancer.java

@@ -1946,7 +1946,9 @@ public class TestBalancer {
   public void testBalancerWithStripedFile() throws Exception {
     Configuration conf = new Configuration();
     initConfWithStripe(conf);
+    NameNodeConnector.setWrite2IdFile(true);
     doTestBalancerWithStripedFile(conf);
+    NameNodeConnector.setWrite2IdFile(false);
   }
 
   private void doTestBalancerWithStripedFile(Configuration conf) throws Exception {