HDFS-6432. Add snapshot related APIs to webhdfs. Contributed by Jing Zhao.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1596334 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -372,6 +372,8 @@ Release 2.5.0 - UNRELEASED
     HDFS-6345. DFS.listCacheDirectives() should allow filtering based on
     cache directive ID. (wang)
 
+    HDFS-6432. Add snapshot related APIs to webhdfs. (jing9)
+
   OPTIMIZATIONS
 
     HDFS-6214. Webhdfs has poor throughput for files >2GB (daryn)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/web/resources/NamenodeWebHdfsMethods.java

@@ -88,6 +88,7 @@ import org.apache.hadoop.hdfs.web.resources.LengthParam;
 import org.apache.hadoop.hdfs.web.resources.ModificationTimeParam;
 import org.apache.hadoop.hdfs.web.resources.NamenodeAddressParam;
 import org.apache.hadoop.hdfs.web.resources.OffsetParam;
+import org.apache.hadoop.hdfs.web.resources.OldSnapshotNameParam;
 import org.apache.hadoop.hdfs.web.resources.OverwriteParam;
 import org.apache.hadoop.hdfs.web.resources.OwnerParam;
 import org.apache.hadoop.hdfs.web.resources.Param;
@@ -98,6 +99,7 @@ import org.apache.hadoop.hdfs.web.resources.RecursiveParam;
 import org.apache.hadoop.hdfs.web.resources.RenameOptionSetParam;
 import org.apache.hadoop.hdfs.web.resources.RenewerParam;
 import org.apache.hadoop.hdfs.web.resources.ReplicationParam;
+import org.apache.hadoop.hdfs.web.resources.SnapshotNameParam;
 import org.apache.hadoop.hdfs.web.resources.TokenArgumentParam;
 import org.apache.hadoop.hdfs.web.resources.UriFsPathParam;
 import org.apache.hadoop.hdfs.web.resources.UserParam;
@@ -341,12 +343,16 @@ public class NamenodeWebHdfsMethods {
       @QueryParam(TokenArgumentParam.NAME) @DefaultValue(TokenArgumentParam.DEFAULT)
           final TokenArgumentParam delegationTokenArgument,
       @QueryParam(AclPermissionParam.NAME) @DefaultValue(AclPermissionParam.DEFAULT) 
-          final AclPermissionParam aclPermission
+          final AclPermissionParam aclPermission,
+      @QueryParam(SnapshotNameParam.NAME) @DefaultValue(SnapshotNameParam.DEFAULT)
+          final SnapshotNameParam snapshotName,
+      @QueryParam(OldSnapshotNameParam.NAME) @DefaultValue(OldSnapshotNameParam.DEFAULT)
+          final OldSnapshotNameParam oldSnapshotName
           )throws IOException, InterruptedException {
     return put(ugi, delegation, username, doAsUser, ROOT, op, destination,
         owner, group, permission, overwrite, bufferSize, replication,
         blockSize, modificationTime, accessTime, renameOptions, createParent,
-        delegationTokenArgument,aclPermission);
+        delegationTokenArgument, aclPermission, snapshotName, oldSnapshotName);
   }
 
   /** Handle HTTP PUT request. */
@@ -392,12 +398,17 @@ public class NamenodeWebHdfsMethods {
       @QueryParam(TokenArgumentParam.NAME) @DefaultValue(TokenArgumentParam.DEFAULT)
           final TokenArgumentParam delegationTokenArgument,
       @QueryParam(AclPermissionParam.NAME) @DefaultValue(AclPermissionParam.DEFAULT) 
-          final AclPermissionParam aclPermission
+          final AclPermissionParam aclPermission,
+      @QueryParam(SnapshotNameParam.NAME) @DefaultValue(SnapshotNameParam.DEFAULT)
+          final SnapshotNameParam snapshotName,
+      @QueryParam(OldSnapshotNameParam.NAME) @DefaultValue(OldSnapshotNameParam.DEFAULT)
+          final OldSnapshotNameParam oldSnapshotName
       ) throws IOException, InterruptedException {
 
     init(ugi, delegation, username, doAsUser, path, op, destination, owner,
         group, permission, overwrite, bufferSize, replication, blockSize,
-        modificationTime, accessTime, renameOptions, delegationTokenArgument,aclPermission);
+        modificationTime, accessTime, renameOptions, delegationTokenArgument,
+        aclPermission, snapshotName, oldSnapshotName);
 
     return ugi.doAs(new PrivilegedExceptionAction<Response>() {
       @Override
@@ -407,7 +418,8 @@ public class NamenodeWebHdfsMethods {
               path.getAbsolutePath(), op, destination, owner, group,
               permission, overwrite, bufferSize, replication, blockSize,
               modificationTime, accessTime, renameOptions, createParent,
-              delegationTokenArgument,aclPermission);
+              delegationTokenArgument, aclPermission, snapshotName,
+              oldSnapshotName);
         } finally {
           reset();
         }
@@ -435,7 +447,9 @@ public class NamenodeWebHdfsMethods {
       final RenameOptionSetParam renameOptions,
       final CreateParentParam createParent,
       final TokenArgumentParam delegationTokenArgument,
-      final AclPermissionParam aclPermission
+      final AclPermissionParam aclPermission,
+      final SnapshotNameParam snapshotName,
+      final OldSnapshotNameParam oldSnapshotName
       ) throws IOException, URISyntaxException {
 
     final Configuration conf = (Configuration)context.getAttribute(JspHelper.CURRENT_CONF);
@@ -535,6 +549,21 @@ public class NamenodeWebHdfsMethods {
       np.setAcl(fullpath, aclPermission.getAclPermission(true));
       return Response.ok().type(MediaType.APPLICATION_OCTET_STREAM).build();
     }
+    case CREATESNAPSHOT: {
+      String snapshotPath = np.createSnapshot(fullpath, snapshotName.getValue());
+      final String js = JsonUtil.toJsonString(
+          org.apache.hadoop.fs.Path.class.getSimpleName(), snapshotPath);
+      return Response.ok(js).type(MediaType.APPLICATION_JSON).build();
+    }
+    case DELETESNAPSHOT: {
+      np.deleteSnapshot(fullpath, snapshotName.getValue());
+      return Response.ok().type(MediaType.APPLICATION_OCTET_STREAM).build();
+    }
+    case RENAMESNAPSHOT: {
+      np.renameSnapshot(fullpath, oldSnapshotName.getValue(),
+          snapshotName.getValue());
+      return Response.ok().type(MediaType.APPLICATION_OCTET_STREAM).build();
+    }
     default:
       throw new UnsupportedOperationException(op + " is not supported");
     }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/WebHdfsFileSystem.java

@@ -874,6 +874,38 @@ public class WebHdfsFileSystem extends FileSystem
     new FsPathRunner(op, p, new AclPermissionParam(aclSpec)).run();
   }
 
+  @Override
+  public Path createSnapshot(final Path path, final String snapshotName) 
+      throws IOException {
+    statistics.incrementWriteOps(1);
+    final HttpOpParam.Op op = PutOpParam.Op.CREATESNAPSHOT;
+    Path spath = new FsPathResponseRunner<Path>(op, path,
+        new SnapshotNameParam(snapshotName)) {
+      @Override
+      Path decodeResponse(Map<?,?> json) {
+        return new Path((String) json.get(Path.class.getSimpleName()));
+      }
+    }.run();
+    return spath;
+  }
+
+  @Override
+  public void deleteSnapshot(final Path path, final String snapshotName)
+      throws IOException {
+    statistics.incrementWriteOps(1);
+    final HttpOpParam.Op op = PutOpParam.Op.DELETESNAPSHOT;
+    new FsPathRunner(op, path, new SnapshotNameParam(snapshotName)).run();
+  }
+
+  @Override
+  public void renameSnapshot(final Path path, final String snapshotOldName,
+      final String snapshotNewName) throws IOException {
+    statistics.incrementWriteOps(1);
+    final HttpOpParam.Op op = PutOpParam.Op.RENAMESNAPSHOT;
+    new FsPathRunner(op, path, new OldSnapshotNameParam(snapshotOldName),
+        new SnapshotNameParam(snapshotNewName)).run();
+  }
+
   @Override
   public boolean setReplication(final Path p, final short replication
      ) throws IOException {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/OldSnapshotNameParam.java

@@ -0,0 +1,40 @@
+/**
+ * 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.web.resources;
+
+/**
+ * The old snapshot name parameter for renameSnapshot operation.
+ */
+public class OldSnapshotNameParam extends StringParam {
+  /** Parameter name. */
+  public static final String NAME = "oldsnapshotname";
+
+  /** Default parameter value. */
+  public static final String DEFAULT = "";
+
+  private static final Domain DOMAIN = new Domain(NAME, null);
+  
+  public OldSnapshotNameParam(final String str) {
+    super(DOMAIN, str != null && !str.equals(DEFAULT) ? str : null);
+  }
+
+  @Override
+  public String getName() {
+    return NAME;
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/PutOpParam.java

@@ -43,6 +43,10 @@ public class PutOpParam extends HttpOpParam<PutOpParam.Op> {
     REMOVEACL(false, HttpURLConnection.HTTP_OK),
     SETACL(false, HttpURLConnection.HTTP_OK),
 
+    CREATESNAPSHOT(false, HttpURLConnection.HTTP_OK),
+    DELETESNAPSHOT(false, HttpURLConnection.HTTP_OK),
+    RENAMESNAPSHOT(false, HttpURLConnection.HTTP_OK),
+    
     NULL(false, HttpURLConnection.HTTP_NOT_IMPLEMENTED);
 
     final boolean doOutputAndRedirect;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/SnapshotNameParam.java

@@ -0,0 +1,41 @@
+/**
+ * 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.web.resources;
+
+/**
+ * The snapshot name parameter for createSnapshot and deleteSnapshot operation.
+ * Also used to indicate the new snapshot name for renameSnapshot operation.
+ */
+public class SnapshotNameParam extends StringParam {
+  /** Parameter name. */
+  public static final String NAME = "snapshotname";
+
+  /** Default parameter value. */
+  public static final String DEFAULT = "";
+
+  private static final Domain DOMAIN = new Domain(NAME, null);
+  
+  public SnapshotNameParam(final String str) {
+    super(DOMAIN, str != null && !str.equals(DEFAULT) ? str : null);
+  }
+
+  @Override
+  public String getName() {
+    return NAME;
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestWebHDFS.java

@@ -18,6 +18,8 @@
 
 package org.apache.hadoop.hdfs.web;
 
+import static org.junit.Assert.fail;
+
 import java.io.IOException;
 import java.net.URISyntaxException;
 import java.security.PrivilegedExceptionAction;
@@ -34,8 +36,10 @@ import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.permission.FsAction;
 import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.DistributedFileSystem;
 import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.hdfs.server.namenode.snapshot.SnapshotTestHelper;
 import org.apache.hadoop.hdfs.server.namenode.web.resources.NamenodeWebHdfsMethods;
 import org.apache.hadoop.hdfs.TestDFSClientRetries;
 import org.apache.hadoop.security.UserGroupInformation;
@@ -326,4 +330,119 @@ public class TestWebHDFS {
     Assert.assertTrue(conf.getBoolean(DFSConfigKeys.DFS_WEBHDFS_ENABLED_KEY,
         false));
   }
+
+  /**
+   * Test snapshot creation through WebHdfs
+   */
+  @Test
+  public void testWebHdfsCreateSnapshot() throws Exception {
+    MiniDFSCluster cluster = null;
+    final Configuration conf = WebHdfsTestUtil.createConf();
+    try {
+      cluster = new MiniDFSCluster.Builder(conf).numDataNodes(0).build();
+      cluster.waitActive();
+      final DistributedFileSystem dfs = cluster.getFileSystem();
+      final FileSystem webHdfs = WebHdfsTestUtil.getWebHdfsFileSystem(conf,
+          WebHdfsFileSystem.SCHEME);
+
+      final Path foo = new Path("/foo");
+      dfs.mkdirs(foo);
+
+      try {
+        webHdfs.createSnapshot(foo);
+        fail("Cannot create snapshot on a non-snapshottable directory");
+      } catch (Exception e) {
+        GenericTestUtils.assertExceptionContains(
+            "Directory is not a snapshottable directory", e);
+      }
+
+      // allow snapshots on /foo
+      dfs.allowSnapshot(foo);
+      // create snapshots on foo using WebHdfs
+      webHdfs.createSnapshot(foo, "s1");
+      // create snapshot without specifying name
+      final Path spath = webHdfs.createSnapshot(foo, null);
+
+      Assert.assertTrue(webHdfs.exists(spath));
+      final Path s1path = SnapshotTestHelper.getSnapshotRoot(foo, "s1");
+      Assert.assertTrue(webHdfs.exists(s1path));
+    } finally {
+      if (cluster != null) {
+        cluster.shutdown();
+      }
+    }
+  }
+
+  /**
+   * Test snapshot deletion through WebHdfs
+   */
+  @Test
+  public void testWebHdfsDeleteSnapshot() throws Exception {
+    MiniDFSCluster cluster = null;
+    final Configuration conf = WebHdfsTestUtil.createConf();
+    try {
+      cluster = new MiniDFSCluster.Builder(conf).numDataNodes(0).build();
+      cluster.waitActive();
+      final DistributedFileSystem dfs = cluster.getFileSystem();
+      final FileSystem webHdfs = WebHdfsTestUtil.getWebHdfsFileSystem(conf,
+          WebHdfsFileSystem.SCHEME);
+
+      final Path foo = new Path("/foo");
+      dfs.mkdirs(foo);
+      dfs.allowSnapshot(foo);
+
+      webHdfs.createSnapshot(foo, "s1");
+      final Path spath = webHdfs.createSnapshot(foo, null);
+      Assert.assertTrue(webHdfs.exists(spath));
+      final Path s1path = SnapshotTestHelper.getSnapshotRoot(foo, "s1");
+      Assert.assertTrue(webHdfs.exists(s1path));
+
+      // delete the two snapshots
+      webHdfs.deleteSnapshot(foo, "s1");
+      Assert.assertFalse(webHdfs.exists(s1path));
+      webHdfs.deleteSnapshot(foo, spath.getName());
+      Assert.assertFalse(webHdfs.exists(spath));
+    } finally {
+      if (cluster != null) {
+        cluster.shutdown();
+      }
+    }
+  }
+
+  /**
+   * Test snapshot rename through WebHdfs
+   */
+  @Test
+  public void testWebHdfsRenameSnapshot() throws Exception {
+    MiniDFSCluster cluster = null;
+    final Configuration conf = WebHdfsTestUtil.createConf();
+    try {
+      cluster = new MiniDFSCluster.Builder(conf).numDataNodes(0).build();
+      cluster.waitActive();
+      final DistributedFileSystem dfs = cluster.getFileSystem();
+      final FileSystem webHdfs = WebHdfsTestUtil.getWebHdfsFileSystem(conf,
+          WebHdfsFileSystem.SCHEME);
+
+      final Path foo = new Path("/foo");
+      dfs.mkdirs(foo);
+      dfs.allowSnapshot(foo);
+
+      webHdfs.createSnapshot(foo, "s1");
+      final Path s1path = SnapshotTestHelper.getSnapshotRoot(foo, "s1");
+      Assert.assertTrue(webHdfs.exists(s1path));
+
+      // rename s1 to s2
+      webHdfs.renameSnapshot(foo, "s1", "s2");
+      Assert.assertFalse(webHdfs.exists(s1path));
+      final Path s2path = SnapshotTestHelper.getSnapshotRoot(foo, "s2");
+      Assert.assertTrue(webHdfs.exists(s2path));
+
+      webHdfs.deleteSnapshot(foo, "s2");
+      Assert.assertFalse(webHdfs.exists(s2path));
+    } finally {
+      if (cluster != null) {
+        cluster.shutdown();
+      }
+    }
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/resources/TestParam.java

@@ -357,4 +357,12 @@ public class TestParam {
     Assert.assertEquals(p1.getValue(), EnumSet.of(
         Options.Rename.OVERWRITE, Options.Rename.NONE));
   }
+
+  @Test
+  public void testSnapshotNameParam() {
+    final OldSnapshotNameParam s1 = new OldSnapshotNameParam("s1");
+    final SnapshotNameParam s2 = new SnapshotNameParam("s2");
+    Assert.assertEquals("s1", s1.getValue());
+    Assert.assertEquals("s2", s2.getValue());
+  }
 }