HDFS-10195. Ozone: Add container persistence. Contributed by Anu Engineer.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/OzoneConfigKeys.java

@@ -41,6 +41,9 @@ public final class OzoneConfigKeys {
       "dfs.objectstore.trace.enabled";
   public static final boolean DFS_OBJECTSTORE_TRACE_ENABLED_DEFAULT = false;
 
+  public static final String DFS_OZONE_METADATA_DIRS =
+      "dfs.ozone.metadata.dirs";
+
 
   /**
    * There is no need to instantiate this class.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/OzoneConsts.java

@@ -16,7 +16,7 @@
  *  limitations under the License.
  */
 
-package org.apache.hadoop.ozone.web.utils;
+package org.apache.hadoop.ozone;
 
 import org.apache.hadoop.classification.InterfaceAudience;
 
@@ -53,6 +53,20 @@ public final class OzoneConsts {
   public static final String OZONE_USER = "user";
   public static final String OZONE_REQUEST = "request";
 
+  public static final String CONTAINER_EXTENSION = ".container";
+  public static final String CONTAINER_META = ".meta";
+
+  //  container storage is in the following format.
+  //  Data Volume basePath/containers/<containerName>/metadata and
+  //  Data Volume basePath/containers/<containerName>/data/...
+  public static final String CONTAINER_PREFIX  = "containers";
+  public static final String CONTAINER_META_PATH = "metadata";
+  public static final String CONTAINER_DATA_PATH = "data";
+  public static final String CONTAINER_ROOT_PREFIX = "repository";
+
+  public static final String CONTAINER_DB = "container.db";
+
+
 
   /**
    * Supports Bucket Versioning.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/container/common/helpers/ContainerData.java

@@ -35,8 +35,9 @@ public class ContainerData {
 
   private final String containerName;
   private final Map<String, String> metadata;
-
+  private String dbPath;  // Path to Level DB Store.
-  private String path;
+  // Path to Physical file system where container and checksum are stored.
+  private String containerFilePath;
 
   /**
    * Constructs a  ContainerData Object.
@@ -63,8 +64,13 @@ public class ContainerData {
     }
 
     if (protoData.hasContainerPath()) {
-      data.setPath(protoData.getContainerPath());
+      data.setContainerPath(protoData.getContainerPath());
     }
+
+    if (protoData.hasDbPath()) {
+      data.setDBPath(protoData.getDbPath());
+    }
+
     return data;
   }
 
@@ -77,9 +83,15 @@ public class ContainerData {
     ContainerProtos.ContainerData.Builder builder = ContainerProtos
         .ContainerData.newBuilder();
     builder.setName(this.getContainerName());
-    if (this.getPath() != null) {
+
-      builder.setContainerPath(this.getPath());
+    if (this.getDBPath() != null) {
+      builder.setDbPath(this.getDBPath());
     }
+
+    if (this.getContainerPath() != null) {
+      builder.setContainerPath(this.getContainerPath());
+    }
+
     for (Map.Entry<String, String> entry : metadata.entrySet()) {
       ContainerProtos.KeyValue.Builder keyValBuilder =
           ContainerProtos.KeyValue.newBuilder();
@@ -144,8 +156,8 @@ public class ContainerData {
    *
    * @return - path
    */
-  public String getPath() {
+  public String getDBPath() {
-    return path;
+    return dbPath;
   }
 
   /**
@@ -153,8 +165,8 @@ public class ContainerData {
    *
    * @param path - String.
    */
-  public void setPath(String path) {
+  public void setDBPath(String path) {
-    this.path = path;
+    this.dbPath = path;
   }
 
   /**
@@ -167,4 +179,21 @@ public class ContainerData {
   public String getName() {
     return getContainerName();
   }
+
+  /**
+   * Get container file path.
+   * @return - Physical path where container file and checksum is stored.
+   */
+  public String getContainerPath() {
+    return containerFilePath;
+  }
+
+  /**
+   * Set container Path.
+   * @param containerFilePath - File path.
+   */
+  public void setContainerPath(String containerFilePath) {
+    this.containerFilePath = containerFilePath;
+  }
+
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/container/common/helpers/ContainerUtils.java

@@ -19,7 +19,23 @@
 package org.apache.hadoop.ozone.container.common.helpers;
 
 import com.google.common.base.Preconditions;
+import org.apache.commons.io.FileUtils;
+import org.apache.hadoop.fs.FileAlreadyExistsException;
 import org.apache.hadoop.hdfs.ozone.protocol.proto.ContainerProtos;
+import org.apache.hadoop.ozone.OzoneConsts;
+import org.apache.hadoop.ozone.container.common.impl.ContainerManagerImpl;
+import org.apache.hadoop.ozone.container.common.utils.LevelDBStore;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+import static org.apache.commons.io.FilenameUtils.removeExtension;
+import static org.apache.hadoop.ozone.OzoneConsts.CONTAINER_EXTENSION;
+import static org.apache.hadoop.ozone.OzoneConsts.CONTAINER_META;
 
 /**
  * A set of helper functions to create proper responses.
@@ -104,6 +120,134 @@ public final class ContainerUtils {
         "Server does not support this command yet.").build();
   }
 
+  /**
+   * get containerName from a container file.
+   *
+   * @param containerFile - File
+   * @return Name of the container.
+   */
+  public static String getContainerNameFromFile(File containerFile) {
+    Preconditions.checkNotNull(containerFile);
+    return Paths.get(containerFile.getParent()).resolve(
+        removeExtension(containerFile.getName())).toString();
+
+  }
+
+  /**
+   * Verifies that this in indeed a new container.
+   *
+   * @param containerFile - Container File to verify
+   * @param metadataFile  - metadata File to verify
+   * @throws IOException
+   */
+  public static void verifyIsNewContainer(File containerFile, File metadataFile)
+      throws IOException {
+    Logger log = LoggerFactory.getLogger(ContainerManagerImpl.class);
+    if (containerFile.exists()) {
+      log.error("container already exists on disk. File: {}",
+          containerFile.toPath());
+      throw new FileAlreadyExistsException("container already exists on " +
+          "disk.");
+    }
+
+    if (metadataFile.exists()) {
+      log.error("metadata found on disk, but missing container. Refusing to" +
+          " write this container. File: {} ", metadataFile.toPath());
+      throw new FileAlreadyExistsException(("metadata found on disk, but " +
+          "missing container. Refusing to write this container."));
+    }
+
+    File parentPath = new File(containerFile.getParent());
+
+    if (!parentPath.exists() && !parentPath.mkdirs()) {
+      log.error("Unable to create parent path. Path: {}",
+          parentPath.toString());
+      throw new IOException("Unable to create container directory.");
+    }
+
+    if (!containerFile.createNewFile()) {
+      log.error("creation of a new container file failed. File: {}",
+          containerFile.toPath());
+      throw new IOException("creation of a new container file failed.");
+    }
+
+    if (!metadataFile.createNewFile()) {
+      log.error("creation of the metadata file failed. File: {}",
+          metadataFile.toPath());
+      throw new IOException("creation of a new container file failed.");
+    }
+  }
+
+  /**
+   * creates a Metadata DB for the specified container.
+   *
+   * @param containerPath - Container Path.
+   * @throws IOException
+   */
+  public static Path createMetadata(Path containerPath) throws IOException {
+    Preconditions.checkNotNull(containerPath);
+    containerPath = containerPath.resolve(OzoneConsts.CONTAINER_META_PATH);
+    if (!containerPath.toFile().mkdirs()) {
+      throw new IOException("Unable to create directory for metadata storage." +
+          " Path {}" + containerPath);
+    }
+    containerPath = containerPath.resolve(OzoneConsts.CONTAINER_DB);
+    LevelDBStore store = new LevelDBStore(containerPath.toFile(), true);
+
+    // we close since the SCM pre-creates containers.
+    // we will open and put Db handle into a cache when keys are being created
+    // in a container.
+
+    store.close();
+    return containerPath;
+  }
+
+  /**
+   * remove Container if it is empty.
+   * <p/>
+   * There are three things we need to delete.
+   * <p/>
+   * 1. Container file and metadata file. 2. The Level DB file 3. The path that
+   * we created on the data location.
+   *
+   * @param containerData - Data of the container to remove.
+   * @throws IOException
+   */
+  public static void removeContainer(ContainerData containerData) throws
+      IOException {
+    Preconditions.checkNotNull(containerData);
+
+    // TODO : Check if there are any keys. This needs to be done
+    // by calling into key layer code, hence this is a TODO for now.
+
+    Path dbPath = Paths.get(containerData.getDBPath());
+
+    // Delete the DB File.
+    FileUtils.forceDelete(dbPath.toFile());
+    dbPath = dbPath.getParent();
+
+    // Delete all Metadata in the Data directories for this containers.
+    if (dbPath != null) {
+      FileUtils.deleteDirectory(dbPath.toFile());
+      dbPath = dbPath.getParent();
+    }
+
+    // now delete the container directory, this means that all key data dirs
+    // will be removed too.
+    if (dbPath != null) {
+      FileUtils.deleteDirectory(dbPath.toFile());
+    }
+
+    // Delete the container metadata from the metadata locations.
+    String rootPath = getContainerNameFromFile(new File(containerData
+        .getContainerPath()));
+    Path containerPath = Paths.get(rootPath.concat(CONTAINER_EXTENSION));
+    Path metaPath = Paths.get(rootPath.concat(CONTAINER_META));
+
+    FileUtils.forceDelete(containerPath.toFile());
+    FileUtils.forceDelete(metaPath.toFile());
+  }
+
   private ContainerUtils() {
     //never constructed.
   }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/container/common/impl/ContainerLocationManagerImpl.java

@@ -0,0 +1,113 @@
+/*
+ * 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.ozone.container.common.impl;
+
+import com.google.common.base.Preconditions;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsDatasetSpi;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi;
+import org.apache.hadoop.ozone.OzoneConsts;
+import org.apache.hadoop.ozone.container.common.interfaces.ContainerLocationManager;
+
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * A class that tells the ContainerManager where to place the containers.
+ * Please note : There is *no* one-to-one correlation between metadata
+ * locations and data locations.
+ *
+ *  For example : A user could map all container files to a
+ *  SSD but leave data/metadata on bunch of other disks.
+ */
+public class ContainerLocationManagerImpl implements ContainerLocationManager {
+  private static final Logger LOG =
+      LoggerFactory.getLogger(ContainerLocationManagerImpl.class);
+
+
+  private final Configuration conf;
+  private final FsDatasetSpi dataset;
+  private final Path[] volumePaths;
+  private int currentIndex;
+  private final List<Path> locations;
+
+
+  /**
+   * Constructs a Location Manager.
+   * @param conf - Configuration.
+   */
+  public ContainerLocationManagerImpl(Configuration conf, List<Path> locations,
+                                      FsDatasetSpi dataset) throws IOException {
+    this.conf = conf;
+    this.dataset = dataset;
+    List<Path> pathList = new LinkedList<>();
+    FsDatasetSpi.FsVolumeReferences references;
+    try {
+      synchronized (this.dataset) {
+        references = this.dataset.getFsVolumeReferences();
+        for (int ndx = 0; ndx < references.size(); ndx++) {
+          FsVolumeSpi vol = references.get(ndx);
+          pathList.add(Paths.get(vol.getBasePath()));
+        }
+        references.close();
+        volumePaths = pathList.toArray(new Path[pathList.size()]);
+        this.locations = locations;
+      }
+    } catch (IOException ex) {
+      LOG.error("Unable to get volume paths.", ex);
+      throw new IOException("Internal error", ex);
+    }
+
+  }
+
+  /**
+   * Returns the path where the container should be placed from a set of
+   * locations.
+   *
+   * @return A path where we should place this container and metadata.
+   * @throws IOException
+   */
+  @Override
+  public Path getContainerPath()
+      throws IOException {
+    Preconditions.checkState(locations.size() > 0);
+    int index = currentIndex % locations.size();
+    return locations.get(index).resolve(OzoneConsts.CONTAINER_ROOT_PREFIX);
+  }
+
+  /**
+   * Returns the path where the container Data file are stored.
+   *
+   * @return  a path where we place the LevelDB and data files of a container.
+   * @throws IOException
+   */
+  @Override
+  public Path getDataPath(String containerName) throws IOException {
+    Path currentPath = volumePaths[currentIndex++ % volumePaths.length];
+    currentPath = currentPath.resolve(OzoneConsts.CONTAINER_PREFIX);
+    return currentPath.resolve(containerName);
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/container/common/impl/ContainerManagerImpl.java

@@ -0,0 +1,514 @@
+/*
+ * 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.ozone.container.common.impl;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Preconditions;
+import org.apache.commons.codec.digest.DigestUtils;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileAlreadyExistsException;
+import org.apache.hadoop.hdfs.ozone.protocol.proto.ContainerProtos;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsDatasetSpi;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.hadoop.ozone.container.common.helpers.ContainerData;
+import org.apache.hadoop.ozone.container.common.helpers.ContainerUtils;
+import org.apache.hadoop.ozone.container.common.helpers.Pipeline;
+import org.apache.hadoop.ozone.container.common.interfaces.ContainerLocationManager;
+import org.apache.hadoop.ozone.container.common.interfaces.ContainerManager;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.FilenameFilter;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.security.DigestInputStream;
+import java.security.DigestOutputStream;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.List;
+import java.util.concurrent.ConcurrentNavigableMap;
+import java.util.concurrent.ConcurrentSkipListMap;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+import static org.apache.hadoop.ozone.OzoneConsts.CONTAINER_EXTENSION;
+import static org.apache.hadoop.ozone.OzoneConsts.CONTAINER_META;
+
+/**
+ * A Generic ContainerManagerImpl that will be called from Ozone
+ * ContainerManagerImpl. This allows us to support delta changes to ozone
+ * version without having to rewrite the containerManager.
+ */
+public class ContainerManagerImpl implements ContainerManager {
+  static final Logger LOG =
+      LoggerFactory.getLogger(ContainerManagerImpl.class);
+
+  private final ConcurrentSkipListMap<String, ContainerStatus>
+      containerMap = new ConcurrentSkipListMap<>();
+
+  // This lock follows fair locking policy of first-come first-serve
+  // for waiting threads.
+  private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true);
+  private ContainerLocationManager locationManager;
+
+  /**
+   * Init call that sets up a container Manager.
+   *
+   * @param config        - Configuration.
+   * @param containerDirs - List of Metadata Container locations.
+   * @throws IOException
+   */
+  @Override
+  public void init(Configuration config, List<Path> containerDirs,
+                   FsDatasetSpi dataset)
+      throws IOException {
+
+    Preconditions.checkNotNull(config);
+    Preconditions.checkNotNull(containerDirs);
+    Preconditions.checkState(containerDirs.size() > 0);
+
+    readLock();
+    try {
+      for (Path path : containerDirs) {
+        File directory = path.toFile();
+        if (!directory.isDirectory()) {
+          LOG.error("Invalid path to container metadata directory. path: {}",
+              path.toString());
+          throw new IOException("Invalid path to container metadata directory" +
+              ". " + path);
+        }
+        File[] files = directory.listFiles(new ContainerFilter());
+        if (files != null) {
+          for (File containerFile : files) {
+            String containerPath =
+                ContainerUtils.getContainerNameFromFile(containerFile);
+            Preconditions.checkNotNull(containerPath);
+            readContainerInfo(containerPath);
+          }
+        }
+      }
+      this.locationManager = new ContainerLocationManagerImpl(config,
+          containerDirs, dataset);
+
+    } finally {
+      readUnlock();
+    }
+  }
+
+  /**
+   * Reads the Container Info from a file and verifies that checksum match. If
+   * the checksums match, then that file is added to containerMap.
+   *
+   * @param containerName - Name which points to the persisted container.
+   */
+  private void readContainerInfo(String containerName)
+      throws IOException {
+    Preconditions.checkState(containerName.length() > 0);
+    FileInputStream containerStream = null;
+    DigestInputStream dis = null;
+    FileInputStream metaStream = null;
+    Path cPath = Paths.get(containerName).getFileName();
+    String keyName = null;
+    if (cPath != null) {
+      keyName = cPath.toString();
+    }
+    Preconditions.checkNotNull(keyName);
+
+    try {
+      String containerFileName = containerName.concat(CONTAINER_EXTENSION);
+      String metaFileName = containerName.concat(CONTAINER_META);
+
+      containerStream = new FileInputStream(containerFileName);
+
+      metaStream = new FileInputStream(metaFileName);
+
+      MessageDigest sha = MessageDigest.getInstance("SHA-256");
+
+      dis = new DigestInputStream(containerStream, sha);
+
+      ContainerData containerData = ContainerData.getFromProtBuf(
+          ContainerProtos.ContainerData.parseDelimitedFrom(dis));
+
+
+      ContainerProtos.ContainerMeta meta = ContainerProtos.ContainerMeta
+          .parseDelimitedFrom(metaStream);
+
+      if (meta != null && !DigestUtils.sha256Hex(sha.digest()).equals(meta
+          .getHash())) {
+        throw new IOException("Invalid SHA found for file.");
+      }
+
+      containerMap.put(keyName, new ContainerStatus(containerData, true));
+
+    } catch (IOException | NoSuchAlgorithmException ex) {
+      LOG.error("read failed for file: {} ex: {}",
+          containerName, ex.getMessage());
+
+      // TODO : Add this file to a recovery Queue.
+
+      // Remember that this container is busted and we cannot use it.
+      containerMap.put(keyName, new ContainerStatus(null, false));
+    } finally {
+      IOUtils.closeStream(dis);
+      IOUtils.closeStream(containerStream);
+      IOUtils.closeStream(metaStream);
+    }
+  }
+
+  /**
+   * Creates a container with the given name.
+   *
+   * @param pipeline      -- Nodes which make up this container.
+   * @param containerData - Container Name and metadata.
+   * @throws IOException
+   */
+  @Override
+  public void createContainer(Pipeline pipeline, ContainerData containerData)
+      throws IOException {
+    Preconditions.checkNotNull(containerData);
+
+    writeLock();
+    try {
+      if (containerMap.containsKey(containerData.getName())) {
+        throw new FileAlreadyExistsException("container already exists.");
+      }
+
+      // This is by design. We first write and close the
+      // container Info and metadata to a directory.
+      // Then read back and put that info into the containerMap.
+      // This allows us to make sure that our write is consistent.
+
+      writeContainerInfo(containerData);
+      File cFile = new File(containerData.getContainerPath());
+      readContainerInfo(ContainerUtils.getContainerNameFromFile(cFile));
+    } catch (NoSuchAlgorithmException ex) {
+      throw new IOException("failed to create container", ex);
+
+    } finally {
+      writeUnlock();
+    }
+
+  }
+
+  /**
+   * Writes a container to a chosen location and updates the container Map.
+   *
+   * The file formats of ContainerData and Container Meta is the following.
+   *
+   * message ContainerData {
+   * required string name = 1;
+   * repeated KeyValue metadata = 2;
+   * optional string dbPath = 3;
+   * optional string containerPath = 4;
+   * }
+   *
+   * message ContainerMeta {
+   * required string fileName = 1;
+   * required string hash = 2;
+   * }
+   *
+   * @param containerData - container Data
+   */
+  private void writeContainerInfo(ContainerData containerData)
+      throws IOException, NoSuchAlgorithmException {
+
+    Preconditions.checkNotNull(this.locationManager);
+
+    FileOutputStream containerStream = null;
+    DigestOutputStream dos = null;
+    FileOutputStream metaStream = null;
+    Path location = locationManager.getContainerPath();
+
+    File containerFile = location.resolve(containerData
+        .getContainerName().concat(CONTAINER_EXTENSION))
+        .toFile();
+
+    File metadataFile = location.resolve(containerData
+        .getContainerName().concat(CONTAINER_META))
+        .toFile();
+
+    try {
+      ContainerUtils.verifyIsNewContainer(containerFile, metadataFile);
+
+      Path metadataPath = this.locationManager.getDataPath(
+          containerData.getContainerName());
+      metadataPath = ContainerUtils.createMetadata(metadataPath);
+
+      containerStream = new FileOutputStream(containerFile);
+      metaStream = new FileOutputStream(metadataFile);
+      MessageDigest sha = MessageDigest.getInstance("SHA-256");
+
+      dos = new DigestOutputStream(containerStream, sha);
+      containerData.setDBPath(metadataPath.toString());
+      containerData.setContainerPath(containerFile.toString());
+
+      ContainerProtos.ContainerData protoData = containerData
+          .getProtoBufMessage();
+      protoData.writeDelimitedTo(dos);
+
+      ContainerProtos.ContainerMeta protoMeta = ContainerProtos
+          .ContainerMeta.newBuilder()
+          .setFileName(containerFile.toString())
+          .setHash(DigestUtils.sha256Hex(sha.digest()))
+          .build();
+      protoMeta.writeDelimitedTo(metaStream);
+
+    } catch (IOException ex) {
+
+      // TODO : we need to clean up partially constructed files
+      // The proper way to do would be for a thread
+      // to read all these 3 artifacts and make sure they are
+      // sane. That info needs to come from the replication
+      // pipeline, and if not consistent delete these file.
+
+      // In case of ozone this is *not* a deal breaker since
+      // SCM is guaranteed to generate unique container names.
+
+      LOG.error("creation of container failed. Name: {} "
+          , containerData.getContainerName());
+      throw ex;
+    } finally {
+      IOUtils.closeStream(dos);
+      IOUtils.closeStream(containerStream);
+      IOUtils.closeStream(metaStream);
+    }
+  }
+
+  /**
+   * Deletes an existing container.
+   *
+   * @param pipeline      - nodes that make this container.
+   * @param containerName - name of the container.
+   * @throws IOException
+   */
+  @Override
+  public void deleteContainer(Pipeline pipeline, String containerName) throws
+      IOException {
+    Preconditions.checkState(containerName.length() > 0);
+    writeLock();
+    try {
+      ContainerStatus status = containerMap.get(containerName);
+      if (status == null) {
+        LOG.info("No such container. Name: {}", containerName);
+        throw new IOException("No such container. Name : " + containerName);
+      }
+      ContainerUtils.removeContainer(status.containerData);
+      containerMap.remove(containerName);
+    } finally {
+      writeUnlock();
+    }
+
+  }
+
+  /**
+   * A simple interface for container Iterations.
+   * <p/>
+   * This call make no guarantees about consistency of the data between
+   * different list calls. It just returns the best known data at that point of
+   * time. It is possible that using this iteration you can miss certain
+   * container from the listing.
+   *
+   * @param prevKey - Previous Key Value or empty String.
+   * @param count   - how many to return
+   * @param data    - Actual containerData
+   * @throws IOException
+   */
+  @Override
+  public void listContainer(String prevKey, long count,
+                            List<ContainerData> data) throws IOException {
+    Preconditions.checkNotNull(data);
+    readLock();
+    try {
+      ConcurrentNavigableMap<String, ContainerStatus> map = null;
+      if (prevKey.length() == 0) {
+        map = containerMap.tailMap(containerMap.firstKey(), true);
+      } else {
+        map = containerMap.tailMap(prevKey, false);
+      }
+
+      int currentCount = 0;
+      for (ContainerStatus entry : map.values()) {
+        if (currentCount < count) {
+          data.add(entry.getContainer());
+          currentCount++;
+        } else {
+          return;
+        }
+      }
+    } finally {
+      readUnlock();
+    }
+  }
+
+  /**
+   * Get metadata about a specific container.
+   *
+   * @param containerName - Name of the container
+   * @return ContainerData - Container Data.
+   * @throws IOException
+   */
+  @Override
+  public ContainerData readContainer(String containerName) throws IOException {
+    return containerMap.get(containerName).getContainer();
+  }
+
+  /**
+   * Supports clean shutdown of container.
+   *
+   * @throws IOException
+   */
+  @Override
+  public void shutdown() throws IOException {
+
+  }
+
+
+  @VisibleForTesting
+  ConcurrentSkipListMap<String, ContainerStatus> getContainerMap() {
+    return containerMap;
+  }
+
+  /**
+   * Acquire read lock.
+   */
+  @Override
+  public void readLock() {
+    this.lock.readLock().lock();
+
+  }
+
+  /**
+   * Release read lock.
+   */
+  @Override
+  public void readUnlock() {
+    this.lock.readLock().unlock();
+  }
+
+  /**
+   * Check if the current thread holds read lock.
+   */
+  @Override
+  public boolean hasReadLock() {
+    return this.lock.readLock().tryLock();
+  }
+
+  /**
+   * Acquire write lock.
+   */
+  @Override
+  public void writeLock() {
+    this.lock.writeLock().lock();
+  }
+
+  /**
+   * Acquire write lock, unless interrupted while waiting.
+   */
+  @Override
+  public void writeLockInterruptibly() throws InterruptedException {
+    this.lock.writeLock().lockInterruptibly();
+
+  }
+
+  /**
+   * Release write lock.
+   */
+  @Override
+  public void writeUnlock() {
+    this.lock.writeLock().unlock();
+
+  }
+
+  /**
+   * Check if the current thread holds write lock.
+   */
+  @Override
+  public boolean hasWriteLock() {
+    return this.lock.writeLock().isHeldByCurrentThread();
+  }
+
+  /**
+   * Filter out only container files from the container metadata dir.
+   */
+  private static class ContainerFilter implements FilenameFilter {
+    /**
+     * Tests if a specified file should be included in a file list.
+     *
+     * @param dir  the directory in which the file was found.
+     * @param name the name of the file.
+     * @return <code>true</code> if and only if the name should be included in
+     * the file list; <code>false</code> otherwise.
+     */
+    @Override
+    public boolean accept(File dir, String name) {
+      return name.endsWith(CONTAINER_EXTENSION);
+    }
+  }
+
+  /**
+   * This is an immutable class that represents the state of a container. if the
+   * container reading encountered an error when we boot up we will post that
+   * info to a recovery queue and keep the info in the containerMap.
+   * <p/>
+   * if and when the issue is fixed, the expectation is that this entry will be
+   * deleted by the recovery thread from the containerMap and will insert entry
+   * instead of modifying this class.
+   */
+  @VisibleForTesting
+  static class ContainerStatus {
+    private final ContainerData containerData;
+    private final boolean active;
+
+    /**
+     * Creates a Container Status class.
+     *
+     * @param containerData - ContainerData.
+     * @param active        - Active or not active.
+     */
+    public ContainerStatus(ContainerData containerData, boolean active) {
+      this.containerData = containerData;
+      this.active = active;
+    }
+
+    /**
+     * Returns container if it is active. It is not active if we have had an
+     * error and we are waiting for the background threads to fix the issue.
+     *
+     * @return ContainerData.
+     */
+    public ContainerData getContainer() {
+      if (active) {
+        return containerData;
+      }
+      return null;
+    }
+
+    /**
+     * Indicates if a container is Active.
+     *
+     * @return
+     */
+    public boolean isActive() {
+      return active;
+    }
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/container/common/interfaces/ContainerLocationManager.java

@@ -0,0 +1,44 @@
+/*
+ * 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.ozone.container.common.interfaces;
+
+import java.io.IOException;
+import java.nio.file.Path;
+
+/**
+ * Returns physical path locations, where the containers will be created.
+ */
+public interface ContainerLocationManager {
+  /**
+   * Returns the path where the container should be placed from a set of
+   * locations.
+   *
+   * @return A path where we should place this container and metadata.
+   * @throws IOException
+   */
+  Path getContainerPath() throws IOException;
+
+  /**
+   * Returns the path where the container Data file are stored.
+   *
+   * @return a path where we place the LevelDB and data files of a container.
+   * @throws IOException
+   */
+  Path getDataPath(String containerName) throws IOException;
+
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/container/common/interfaces/ContainerManager.java

@@ -20,18 +20,35 @@ package org.apache.hadoop.ozone.container.common.interfaces;
 
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsDatasetSpi;
+import org.apache.hadoop.hdfs.util.RwLock;
 import org.apache.hadoop.ozone.container.common.helpers.ContainerData;
 import org.apache.hadoop.ozone.container.common.helpers.Pipeline;
 
 import java.io.IOException;
+import java.nio.file.Path;
 import java.util.List;
 
+
 /**
  * Interface for container operations.
  */
 @InterfaceAudience.Private
 @InterfaceStability.Unstable
-public interface ContainerManager {
+public interface ContainerManager extends RwLock {
+
+  /**
+   * Init call that sets up a container Manager.
+   *
+   * @param config  - Configuration.
+   * @param containerDirs - List of Metadata Container locations.
+   * @param dataset - FSDataset.
+   * @throws IOException
+   */
+  void init(Configuration config, List<Path> containerDirs,
+            FsDatasetSpi dataset)
+      throws IOException;
 
   /**
    * Creates a container with the given name.
@@ -56,20 +73,28 @@ public interface ContainerManager {
   /**
    * As simple interface for container Iterations.
    *
-   * @param start - Starting index
+   * @param prevKey - Starting KeyValue
    * @param count - how many to return
    * @param data  - Actual containerData
    * @throws IOException
    */
-  void listContainer(long start, long count, List<ContainerData> data)
+  void listContainer(String prevKey, long count, List<ContainerData> data)
       throws IOException;
 
   /**
    * Get metadata about a specific container.
    *
    * @param containerName - Name of the container
-   * @return ContainerData
+   * @return ContainerData - Container Data.
    * @throws IOException
    */
   ContainerData readContainer(String containerName) throws IOException;
+
+  /**
+   * Supports clean shutdown of container.
+   *
+   * @throws IOException
+   */
+  void shutdown() throws IOException;
+
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/container/common/transport/client/XceiverClient.java

@@ -26,10 +26,10 @@ import io.netty.channel.nio.NioEventLoopGroup;
 import io.netty.channel.socket.nio.NioSocketChannel;
 import io.netty.handler.logging.LogLevel;
 import io.netty.handler.logging.LoggingHandler;
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.ozone.protocol.proto.ContainerProtos;
 import org.apache.hadoop.hdfs.protocol.DatanodeID;
 import org.apache.hadoop.ozone.OzoneConfigKeys;
-import org.apache.hadoop.ozone.OzoneConfiguration;
 import org.apache.hadoop.ozone.container.common.helpers.Pipeline;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -42,7 +42,7 @@ import java.io.IOException;
 public class XceiverClient {
   static final Logger LOG = LoggerFactory.getLogger(XceiverClient.class);
   private final Pipeline pipeline;
-  private final OzoneConfiguration config;
+  private final Configuration config;
   private ChannelFuture channelFuture;
   private Bootstrap b;
   private EventLoopGroup group;
@@ -53,7 +53,7 @@ public class XceiverClient {
    * @param pipeline - Pipeline that defines the machines.
    * @param config -- Ozone Config
    */
-  public XceiverClient(Pipeline pipeline, OzoneConfiguration config) {
+  public XceiverClient(Pipeline pipeline, Configuration config) {
     Preconditions.checkNotNull(pipeline);
     Preconditions.checkNotNull(config);
     this.pipeline = pipeline;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/container/common/transport/server/XceiverServer.java

@@ -26,8 +26,8 @@ import io.netty.channel.nio.NioEventLoopGroup;
 import io.netty.channel.socket.nio.NioServerSocketChannel;
 import io.netty.handler.logging.LogLevel;
 import io.netty.handler.logging.LoggingHandler;
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.ozone.OzoneConfigKeys;
-import org.apache.hadoop.ozone.OzoneConfiguration;
 import org.apache.hadoop.ozone.container.common.interfaces.ContainerDispatcher;
 
 /**
@@ -47,7 +47,7 @@ public final class XceiverServer {
    *
    * @param conf - Configuration
    */
-  public XceiverServer(OzoneConfiguration conf,
+  public XceiverServer(Configuration conf,
                        ContainerDispatcher dispatcher) {
     Preconditions.checkNotNull(conf);
     this.port = conf.getInt(OzoneConfigKeys.DFS_OZONE_CONTAINER_IPC_PORT,

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/container/common/utils/LevelDBStore.java

@@ -16,37 +16,39 @@
  *  limitations under the License.
  */
 
-package org.apache.hadoop.ozone.web.localstorage;
+package org.apache.hadoop.ozone.container.common.utils;
 
 import org.fusesource.leveldbjni.JniDBFactory;
 import org.iq80.leveldb.DB;
+import org.iq80.leveldb.DBIterator;
 import org.iq80.leveldb.Options;
 
 import java.io.File;
 import java.io.IOException;
 
 /**
- * OzoneLevelDBStore is used by the local
+ * LevelDB interface.
- * OzoneStore which is used in testing.
  */
-class OzoneLevelDBStore {
+public class LevelDBStore {
   private DB db;
+  private final File dbFile;
 
   /**
    * Opens a DB file.
    *
    * @param dbPath          - DB File path
    * @param createIfMissing - Create if missing
-   *
    * @throws IOException
    */
-  OzoneLevelDBStore(File dbPath, boolean createIfMissing) throws IOException {
+  public LevelDBStore(File dbPath, boolean createIfMissing) throws
+      IOException {
     Options options = new Options();
     options.createIfMissing(createIfMissing);
     db = JniDBFactory.factory.open(dbPath, options);
     if (db == null) {
       throw new IOException("Db is null");
     }
+    this.dbFile = dbPath;
   }
 
   /**
@@ -63,7 +65,6 @@ class OzoneLevelDBStore {
    * Get Key.
    *
    * @param key key
-   *
    * @return value
    */
   public byte[] get(byte[] key) {
@@ -87,4 +88,37 @@ class OzoneLevelDBStore {
   public void close() throws IOException {
     db.close();
   }
+
+  /**
+   * Returns true if the DB is empty.
+   *
+   * @return boolean
+   * @throws IOException
+   */
+  public boolean isEmpty() throws IOException {
+    DBIterator iter = db.iterator();
+    try {
+      iter.seekToFirst();
+      return iter.hasNext();
+    } finally {
+      iter.close();
+    }
+  }
+
+  /**
+   * Returns Java File Object that points to the DB.
+   * @return File
+   */
+  public File getDbFile() {
+    return dbFile;
+  }
+
+  /**
+   * Returns the actual levelDB object.
+   * @return DB handle.
+   */
+  public DB getDB() {
+    return db;
+  }
+
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/container/ozoneimpl/OzoneContainer.java

@@ -0,0 +1,121 @@
+/**
+ * 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
+ * <p/>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p/>
+ * 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.ozone.container.ozoneimpl;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsDatasetSpi;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi;
+import org.apache.hadoop.ozone.OzoneConfigKeys;
+import org.apache.hadoop.ozone.container.common.impl.ContainerManagerImpl;
+import org.apache.hadoop.ozone.container.common.impl.Dispatcher;
+import org.apache.hadoop.ozone.container.common.interfaces.ContainerDispatcher;
+import org.apache.hadoop.ozone.container.common.interfaces.ContainerManager;
+import org.apache.hadoop.ozone.container.common.transport.server.XceiverServer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.nio.file.Paths;
+import java.util.LinkedList;
+import java.util.List;
+import java.nio.file.Path;
+
+/**
+ * Ozone main class sets up the network server and initializes the container
+ * layer.
+ */
+public class OzoneContainer {
+  private static final Logger LOG =
+      LoggerFactory.getLogger(OzoneContainer.class);
+
+  private final Configuration ozoneConfig;
+  private final FsDatasetSpi dataSet;
+  private final ContainerDispatcher dispatcher;
+  private final ContainerManager manager;
+  private final XceiverServer server;
+
+  /**
+   * Creates a network endpoint and enables Ozone container.
+   *
+   * @param ozoneConfig - Config
+   * @param dataSet     - FsDataset.
+   * @throws IOException
+   */
+  public OzoneContainer(Configuration ozoneConfig, FsDatasetSpi dataSet) throws
+      Exception {
+    List<Path> locations = new LinkedList<>();
+    String[] paths = ozoneConfig.getStrings(OzoneConfigKeys
+        .DFS_OZONE_METADATA_DIRS);
+    if (paths != null && paths.length > 0) {
+      for (String p : paths) {
+        locations.add(Paths.get(p));
+      }
+    } else {
+      getDataDir(dataSet, locations);
+    }
+
+    this.ozoneConfig = ozoneConfig;
+    this.dataSet = dataSet;
+
+    manager = new ContainerManagerImpl();
+    manager.init(this.ozoneConfig, locations, this.dataSet);
+
+    this.dispatcher = new Dispatcher(manager);
+    server = new XceiverServer(this.ozoneConfig, this.dispatcher);
+  }
+
+  /**
+   * Starts serving requests to ozone container.
+   * @throws Exception
+   */
+  public void start() throws Exception {
+    server.start();
+  }
+
+  /**
+   * Stops the ozone container.
+   * @throws Exception
+   */
+  public void stop() throws  Exception {
+    server.stop();
+  }
+
+  /**
+   * Returns a paths to data dirs.
+   * @param dataset - FSDataset.
+   * @param pathList - List of paths.
+   * @throws IOException
+   */
+  private void getDataDir(FsDatasetSpi dataset, List<Path> pathList) throws
+      IOException {
+    FsDatasetSpi.FsVolumeReferences references;
+    try {
+      synchronized (dataset) {
+        references = dataset.getFsVolumeReferences();
+        for (int ndx = 0; ndx < references.size(); ndx++) {
+          FsVolumeSpi vol = references.get(ndx);
+          pathList.add(Paths.get(vol.getBasePath()));
+        }
+        references.close();
+      }
+    } catch (IOException ex) {
+      LOG.error("Unable to get volume paths.", ex);
+      throw new IOException("Internal error", ex);
+    }
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/container/ozoneimpl/package-info.java

@@ -0,0 +1,21 @@
+/**
+ * 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.ozone.container.ozoneimpl;
+/**
+ Ozone main that calls into the container layer
+**/

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/client/OzoneBucket.java

@@ -26,7 +26,7 @@ import org.apache.hadoop.ozone.web.request.OzoneAcl;
 import org.apache.hadoop.ozone.web.response.BucketInfo;
 import org.apache.hadoop.ozone.web.response.KeyInfo;
 import org.apache.hadoop.ozone.web.response.ListKeys;
-import org.apache.hadoop.ozone.web.utils.OzoneConsts;
+import org.apache.hadoop.ozone.OzoneConsts;
 import org.apache.http.HttpEntity;
 import org.apache.http.HttpRequest;
 import org.apache.http.HttpRequestInterceptor;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/client/OzoneVolume.java

@@ -25,7 +25,7 @@ import org.apache.hadoop.ozone.web.request.OzoneQuota;
 import org.apache.hadoop.ozone.web.response.BucketInfo;
 import org.apache.hadoop.ozone.web.response.ListBuckets;
 import org.apache.hadoop.ozone.web.response.VolumeInfo;
-import org.apache.hadoop.ozone.web.utils.OzoneConsts;
+import org.apache.hadoop.ozone.OzoneConsts;
 import org.apache.hadoop.ozone.web.utils.OzoneUtils;
 import org.apache.http.HttpEntity;
 import org.apache.http.HttpResponse;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/handlers/BucketArgs.java

@@ -19,7 +19,7 @@ package org.apache.hadoop.ozone.web.handlers;
 
 import org.apache.hadoop.fs.StorageType;
 import org.apache.hadoop.ozone.web.request.OzoneAcl;
-import org.apache.hadoop.ozone.web.utils.OzoneConsts;
+import org.apache.hadoop.ozone.OzoneConsts;
 
 import java.util.LinkedList;
 import java.util.List;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/handlers/BucketHandler.java

@@ -25,7 +25,7 @@ import org.apache.hadoop.ozone.web.exceptions.OzoneException;
 import org.apache.hadoop.ozone.web.headers.Header;
 import org.apache.hadoop.ozone.web.interfaces.Bucket;
 import org.apache.hadoop.ozone.web.interfaces.StorageHandler;
-import org.apache.hadoop.ozone.web.utils.OzoneConsts;
+import org.apache.hadoop.ozone.OzoneConsts;
 import org.apache.hadoop.ozone.web.utils.OzoneUtils;
 import org.slf4j.MDC;
 
@@ -37,7 +37,7 @@ import java.io.IOException;
 
 import static java.net.HttpURLConnection.HTTP_CREATED;
 import static java.net.HttpURLConnection.HTTP_OK;
-import static org.apache.hadoop.ozone.web.utils.OzoneConsts.OZONE_FUNCTION;
+import static org.apache.hadoop.ozone.OzoneConsts.OZONE_FUNCTION;
 
 
 /**

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/handlers/BucketProcessTemplate.java

@@ -27,7 +27,7 @@ import org.apache.hadoop.ozone.web.interfaces.StorageHandler;
 import org.apache.hadoop.ozone.web.interfaces.UserAuth;
 import org.apache.hadoop.ozone.web.response.BucketInfo;
 import org.apache.hadoop.ozone.web.response.ListKeys;
-import org.apache.hadoop.ozone.web.utils.OzoneConsts;
+import org.apache.hadoop.ozone.OzoneConsts;
 import org.apache.hadoop.ozone.web.utils.OzoneUtils;
 
 import org.slf4j.Logger;
@@ -47,10 +47,11 @@ import java.util.LinkedList;
 import java.util.List;
 
 import static java.net.HttpURLConnection.HTTP_OK;
-import static org.apache.hadoop.ozone.web.utils.OzoneConsts.OZONE_COMPONENT;
+import static org.apache.hadoop.ozone.OzoneConsts.OZONE_COMPONENT;
-import static org.apache.hadoop.ozone.web.utils.OzoneConsts.OZONE_RESOURCE;
+import static org.apache.hadoop.ozone.OzoneConsts.OZONE_RESOURCE;
-import static org.apache.hadoop.ozone.web.utils.OzoneConsts.OZONE_REQUEST;
+import static org.apache.hadoop.ozone.OzoneConsts.OZONE_REQUEST;
-import static org.apache.hadoop.ozone.web.utils.OzoneConsts.OZONE_USER;
+import static org.apache.hadoop.ozone.OzoneConsts.OZONE_USER;
+
 
 
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/handlers/KeyProcessTemplate.java

@@ -44,10 +44,11 @@ import static org.apache.hadoop.ozone.web.exceptions.ErrorTable.INVALID_BUCKET_N
 import static org.apache.hadoop.ozone.web.exceptions.ErrorTable.INVALID_REQUEST;
 import static org.apache.hadoop.ozone.web.exceptions.ErrorTable.SERVER_ERROR;
 import static org.apache.hadoop.ozone.web.exceptions.ErrorTable.newError;
-import static org.apache.hadoop.ozone.web.utils.OzoneConsts.OZONE_COMPONENT;
+import static org.apache.hadoop.ozone.OzoneConsts.OZONE_COMPONENT;
-import static org.apache.hadoop.ozone.web.utils.OzoneConsts.OZONE_REQUEST;
+import static org.apache.hadoop.ozone.OzoneConsts.OZONE_RESOURCE;
-import static org.apache.hadoop.ozone.web.utils.OzoneConsts.OZONE_RESOURCE;
+import static org.apache.hadoop.ozone.OzoneConsts.OZONE_REQUEST;
-import static org.apache.hadoop.ozone.web.utils.OzoneConsts.OZONE_USER;
+import static org.apache.hadoop.ozone.OzoneConsts.OZONE_USER;
+
 
 /**
  * This class abstracts way the repetitive tasks in  Key handling code.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/handlers/VolumeHandler.java

@@ -38,7 +38,7 @@ import java.io.IOException;
 
 import static java.net.HttpURLConnection.HTTP_CREATED;
 import static java.net.HttpURLConnection.HTTP_OK;
-import static org.apache.hadoop.ozone.web.utils.OzoneConsts.OZONE_FUNCTION;
+import static org.apache.hadoop.ozone.OzoneConsts.OZONE_FUNCTION;
 
 /**
  * VolumeHandler handles volume specific HTTP calls.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/handlers/VolumeProcessTemplate.java

@@ -41,10 +41,10 @@ import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.NoSuchFileException;
 
 import static java.net.HttpURLConnection.HTTP_OK;
-import static org.apache.hadoop.ozone.web.utils.OzoneConsts.OZONE_COMPONENT;
+import static org.apache.hadoop.ozone.OzoneConsts.OZONE_COMPONENT;
-import static org.apache.hadoop.ozone.web.utils.OzoneConsts.OZONE_RESOURCE;
+import static org.apache.hadoop.ozone.OzoneConsts.OZONE_RESOURCE;
-import static org.apache.hadoop.ozone.web.utils.OzoneConsts.OZONE_REQUEST;
+import static org.apache.hadoop.ozone.OzoneConsts.OZONE_REQUEST;
-import static org.apache.hadoop.ozone.web.utils.OzoneConsts.OZONE_USER;
+import static org.apache.hadoop.ozone.OzoneConsts.OZONE_USER;
 
 
 /**

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/localstorage/OzoneMetadataManager.java

@@ -25,6 +25,7 @@ import org.slf4j.LoggerFactory;
 import org.slf4j.Logger;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.ozone.OzoneConfigKeys;
+import org.apache.hadoop.ozone.container.common.utils.LevelDBStore;
 import org.apache.hadoop.ozone.web.exceptions.ErrorTable;
 import org.apache.hadoop.ozone.web.exceptions.OzoneException;
 import org.apache.hadoop.ozone.web.handlers.BucketArgs;
@@ -37,7 +38,7 @@ import org.apache.hadoop.ozone.web.response.ListBuckets;
 import org.apache.hadoop.ozone.web.response.ListVolumes;
 import org.apache.hadoop.ozone.web.response.VolumeInfo;
 import org.apache.hadoop.ozone.web.response.VolumeOwner;
-import org.apache.hadoop.ozone.web.utils.OzoneConsts;
+import org.apache.hadoop.ozone.OzoneConsts;
 import org.iq80.leveldb.DBException;
 import org.apache.commons.codec.digest.DigestUtils;
 
@@ -125,8 +126,8 @@ public final class OzoneMetadataManager {
   private static final String USER_DB = "/user.db";
   private static final String META_DB = "/metadata.db";
   private static OzoneMetadataManager bm = null;
-  private OzoneLevelDBStore userDB;
+  private LevelDBStore userDB;
-  private OzoneLevelDBStore metadataDB;
+  private LevelDBStore metadataDB;
   private ReadWriteLock lock;
   private Charset encoding = Charset.forName("UTF-8");
   private String storageRoot;
@@ -154,8 +155,8 @@ public final class OzoneMetadataManager {
     }
 
     try {
-      userDB = new OzoneLevelDBStore(new File(storageRoot + USER_DB), true);
+      userDB = new LevelDBStore(new File(storageRoot + USER_DB), true);
-      metadataDB = new OzoneLevelDBStore(new File(storageRoot + META_DB), true);
+      metadataDB = new LevelDBStore(new File(storageRoot + META_DB), true);
       inProgressObjects = new ConcurrentHashMap<>();
     } catch (IOException ex) {
       LOG.error("Cannot open db :" + ex.getMessage());

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/request/OzoneAcl.java

@@ -19,7 +19,7 @@
 
 package org.apache.hadoop.ozone.web.request;
 
-import org.apache.hadoop.ozone.web.utils.OzoneConsts;
+import org.apache.hadoop.ozone.OzoneConsts;
 
 import java.util.Objects;
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/response/BucketInfo.java

@@ -20,7 +20,7 @@ package org.apache.hadoop.ozone.web.response;
 import com.google.common.base.Preconditions;
 import org.apache.hadoop.fs.StorageType;
 import org.apache.hadoop.ozone.web.request.OzoneAcl;
-import org.apache.hadoop.ozone.web.utils.OzoneConsts;
+import org.apache.hadoop.ozone.OzoneConsts;
 import org.codehaus.jackson.annotate.JsonAutoDetect;
 import org.codehaus.jackson.annotate.JsonMethod;
 import org.codehaus.jackson.map.ObjectMapper;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/userauth/Simple.java

@@ -24,7 +24,7 @@ import org.apache.hadoop.ozone.web.exceptions.OzoneException;
 import org.apache.hadoop.ozone.web.handlers.UserArgs;
 import org.apache.hadoop.ozone.web.headers.Header;
 import org.apache.hadoop.ozone.web.interfaces.UserAuth;
-import org.apache.hadoop.ozone.web.utils.OzoneConsts;
+import org.apache.hadoop.ozone.OzoneConsts;
 
 import javax.ws.rs.core.HttpHeaders;
 import java.util.List;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/utils/OzoneUtils.java

@@ -19,6 +19,7 @@
 package org.apache.hadoop.ozone.web.utils;
 
 import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.ozone.OzoneConsts;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.LengthInputStream;
 import org.apache.hadoop.ozone.web.exceptions.ErrorTable;
 import org.apache.hadoop.ozone.web.exceptions.OzoneException;

hadoop-hdfs-project/hadoop-hdfs/src/main/proto/DatanodeContainerProtocol.proto

@@ -168,7 +168,13 @@ message KeyValue {
 message ContainerData {
   required string name = 1;
   repeated KeyValue metadata = 2;
-  optional string containerPath = 3;
+  optional string dbPath = 3;
+  optional string containerPath = 4;
+}
+
+message ContainerMeta {
+  required string fileName = 1;
+  required string hash = 2;
 }
 
 // Container Messages.

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/ozone/container/common/impl/TestContainerPersistence.java

@@ -0,0 +1,256 @@
+/*
+ * 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.ozone.container.common.impl;
+
+import org.apache.commons.io.FileUtils;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsDatasetSpi;
+import org.apache.hadoop.ozone.OzoneConfigKeys;
+import org.apache.hadoop.ozone.OzoneConfiguration;
+import org.apache.hadoop.ozone.OzoneConsts;
+import org.apache.hadoop.ozone.container.common.helpers.ContainerData;
+import org.apache.hadoop.ozone.container.common.helpers.ContainerUtils;
+import org.apache.hadoop.ozone.container.common.utils.LevelDBStore;
+import org.apache.hadoop.ozone.web.utils.OzoneUtils;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+
+import static org.apache.hadoop.ozone.container.ContainerTestHelper
+    .createSingleNodePipeline;
+import static org.junit.Assert.fail;
+
+/**
+ * Simple tests to verify that container persistence works as expected.
+ */
+public class TestContainerPersistence {
+
+  static String path;
+  static ContainerManagerImpl containerManager;
+  static OzoneConfiguration conf;
+  static FsDatasetSpi fsDataSet;
+  static MiniDFSCluster cluster;
+  static List<Path> pathLists = new LinkedList<>();
+
+  @BeforeClass
+  public static void init() throws IOException {
+    conf = new OzoneConfiguration();
+    URL p = conf.getClass().getResource("");
+    path = p.getPath().concat(
+        TestContainerPersistence.class.getSimpleName());
+    path += conf.getTrimmed(OzoneConfigKeys.DFS_STORAGE_LOCAL_ROOT,
+        OzoneConfigKeys.DFS_STORAGE_LOCAL_ROOT_DEFAULT);
+    conf.set(OzoneConfigKeys.DFS_STORAGE_LOCAL_ROOT, path);
+    conf.setBoolean(OzoneConfigKeys.DFS_OBJECTSTORE_ENABLED_KEY, true);
+    conf.set(OzoneConfigKeys.DFS_STORAGE_HANDLER_TYPE_KEY, "local");
+
+    File containerDir = new File(path);
+    if (containerDir.exists()) {
+      FileUtils.deleteDirectory(new File(path));
+    }
+
+    Assert.assertTrue(containerDir.mkdirs());
+
+    cluster = new MiniDFSCluster.Builder(conf).build();
+    cluster.waitActive();
+    fsDataSet = cluster.getDataNodes().get(0).getFSDataset();
+    containerManager = new ContainerManagerImpl();
+  }
+
+  @AfterClass
+  public static void shutdown() throws IOException {
+    cluster.shutdown();
+    FileUtils.deleteDirectory(new File(path));
+  }
+
+  @Before
+  public void setupPaths() throws IOException {
+    if (!new File(path).exists()) {
+      new File(path).mkdirs();
+    }
+    pathLists.clear();
+    containerManager.getContainerMap().clear();
+    pathLists.add(Paths.get(path));
+    containerManager.init(conf, pathLists, fsDataSet);
+  }
+
+  @After
+  public void cleanupDir() throws IOException {
+    FileUtils.deleteDirectory(new File(path));
+  }
+
+  @Test
+  public void testCreateContainer() throws Exception {
+
+    String containerName = OzoneUtils.getRequestID();
+    ContainerData data = new ContainerData(containerName);
+    data.addMetadata("VOLUME", "shire");
+    data.addMetadata("owner)", "bilbo");
+    containerManager.createContainer(createSingleNodePipeline(), data);
+    Assert.assertTrue(containerManager.getContainerMap()
+        .containsKey(containerName));
+    ContainerManagerImpl.ContainerStatus status = containerManager
+        .getContainerMap().get(containerName);
+
+    Assert.assertTrue(status.isActive());
+    Assert.assertNotNull(status.getContainer().getContainerPath());
+    Assert.assertNotNull(status.getContainer().getDBPath());
+
+
+    Assert.assertTrue(new File(status.getContainer().getContainerPath())
+        .exists());
+
+    String containerPathString = ContainerUtils.getContainerNameFromFile(new
+        File(status.getContainer().getContainerPath()));
+
+    Path meta = Paths.get(containerPathString);
+
+    String metadataFile = meta.toString() + OzoneConsts.CONTAINER_META;
+    Assert.assertTrue(new File(metadataFile).exists());
+
+
+    String dbPath = status.getContainer().getDBPath();
+
+    LevelDBStore store = null;
+    try {
+      store = new LevelDBStore(new File(dbPath), false);
+      Assert.assertNotNull(store.getDB());
+    } finally {
+      if (store != null) {
+        store.close();
+      }
+    }
+  }
+
+  @Test
+  public void testCreateDuplicateContainer() throws Exception {
+    String containerName = OzoneUtils.getRequestID();
+
+    ContainerData data = new ContainerData(containerName);
+    data.addMetadata("VOLUME", "shire");
+    data.addMetadata("owner)", "bilbo");
+    containerManager.createContainer(createSingleNodePipeline(), data);
+    try {
+      containerManager.createContainer(createSingleNodePipeline(), data);
+      fail("Expected Exception not thrown.");
+    } catch (IOException ex) {
+      Assert.assertNotNull(ex);
+    }
+  }
+
+  @Test
+  public void testDeleteContainer() throws Exception {
+    String containerName1 = OzoneUtils.getRequestID();
+    String containerName2 = OzoneUtils.getRequestID();
+
+
+    ContainerData data = new ContainerData(containerName1);
+    data.addMetadata("VOLUME", "shire");
+    data.addMetadata("owner)", "bilbo");
+    containerManager.createContainer(createSingleNodePipeline(), data);
+
+    data = new ContainerData(containerName2);
+    data.addMetadata("VOLUME", "shire");
+    data.addMetadata("owner)", "bilbo");
+    containerManager.createContainer(createSingleNodePipeline(), data);
+
+
+    Assert.assertTrue(containerManager.getContainerMap()
+        .containsKey(containerName1));
+    Assert.assertTrue(containerManager.getContainerMap()
+        .containsKey(containerName2));
+
+    containerManager.deleteContainer(createSingleNodePipeline(),
+        containerName1);
+    Assert.assertFalse(containerManager.getContainerMap()
+        .containsKey(containerName1));
+
+    // Let us make sure that we are able to re-use a container name after
+    // delete.
+
+    data = new ContainerData(containerName1);
+    data.addMetadata("VOLUME", "shire");
+    data.addMetadata("owner)", "bilbo");
+    containerManager.createContainer(createSingleNodePipeline(), data);
+
+    // Assert we still have both containers.
+    Assert.assertTrue(containerManager.getContainerMap()
+        .containsKey(containerName1));
+    Assert.assertTrue(containerManager.getContainerMap()
+        .containsKey(containerName2));
+
+  }
+
+  /**
+   * This test creates 1000 containers and reads them back 5 containers at a
+   * time and verifies that we did get back all containers.
+   *
+   * @throws IOException
+   */
+  @Test
+  public void testListContainer() throws IOException {
+    final int count = 1000;
+    final int step = 5;
+
+    Map<String, ContainerData> testMap = new HashMap<>();
+    for (int x = 0; x < count; x++) {
+      String containerName = OzoneUtils.getRequestID();
+
+      ContainerData data = new ContainerData(containerName);
+      data.addMetadata("VOLUME", "shire");
+      data.addMetadata("owner)", "bilbo");
+      containerManager.createContainer(createSingleNodePipeline(), data);
+      testMap.put(containerName, data);
+    }
+
+    int counter = 0;
+    String prevKey = "";
+    List<ContainerData> results = new LinkedList<>();
+    while (counter < count) {
+      containerManager.listContainer(prevKey, step, results);
+      for (int y = 0; y < results.size(); y++) {
+        testMap.remove(results.get(y).getContainerName());
+      }
+      counter += step;
+      String nextKey = results.get(results.size() - 1).getContainerName();
+
+      //Assert that container is returning results in a sorted fashion.
+      Assert.assertTrue(prevKey.compareTo(nextKey) < 0);
+      prevKey = nextKey;
+      results.clear();
+    }
+    // Assert that we listed all the keys that we had put into
+    // container.
+    Assert.assertTrue(testMap.isEmpty());
+
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/ozone/container/ozoneimpl/TestOzoneContainer.java

@@ -0,0 +1,118 @@
+/*
+ * 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.ozone.container.ozoneimpl;
+
+import org.apache.commons.io.FileUtils;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.hdfs.ozone.protocol.proto.ContainerProtos;
+import org.apache.hadoop.ozone.OzoneConfigKeys;
+import org.apache.hadoop.ozone.OzoneConfiguration;
+import org.apache.hadoop.ozone.container.ContainerTestHelper;
+import org.apache.hadoop.ozone.container.common.helpers.Pipeline;
+import org.apache.hadoop.ozone.container.common.impl.ContainerManagerImpl;
+import org.apache.hadoop.ozone.container.common.transport.client.XceiverClient;
+import org.junit.AfterClass;
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+
+
+public class TestOzoneContainer {
+  @Test
+  public void testCreateOzoneContainer() throws Exception {
+
+    Configuration conf = new OzoneConfiguration();
+    URL p = conf.getClass().getResource("");
+    String  path = p.getPath().concat(
+        TestOzoneContainer.class.getSimpleName());
+    path += conf.getTrimmed(OzoneConfigKeys.DFS_STORAGE_LOCAL_ROOT,
+        OzoneConfigKeys.DFS_STORAGE_LOCAL_ROOT_DEFAULT);
+    conf.set(OzoneConfigKeys.DFS_STORAGE_LOCAL_ROOT, path);
+
+    // We don't start Ozone Container via data node, we will do it
+    // independently in our test path.
+    conf.setBoolean(OzoneConfigKeys.DFS_OBJECTSTORE_ENABLED_KEY, false);
+    conf.set(OzoneConfigKeys.DFS_STORAGE_HANDLER_TYPE_KEY, "local");
+
+    MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
+    cluster.waitActive();
+
+
+    Pipeline pipeline = ContainerTestHelper.createSingleNodePipeline();
+    conf.setInt(OzoneConfigKeys.DFS_OZONE_CONTAINER_IPC_PORT,
+        pipeline.getLeader().getContainerPort());
+    OzoneContainer container = new OzoneContainer(conf, cluster.getDataNodes
+        ().get(0).getFSDataset());
+    container.start();
+
+    XceiverClient client = new XceiverClient(pipeline, conf);
+    client.connect();
+    ContainerProtos.ContainerCommandRequestProto request =
+        ContainerTestHelper.getCreateContainerRequest();
+    ContainerProtos.ContainerCommandResponseProto response =
+        client.sendCommand(request);
+    Assert.assertNotNull(response);
+    Assert.assertTrue(request.getTraceID().equals(response.getTraceID()));
+    container.stop();
+    cluster.shutdown();
+
+  }
+
+
+  @Test
+  public void testOzoneContainerViaDataNode() throws Exception {
+
+    Configuration conf = new OzoneConfiguration();
+    URL p = conf.getClass().getResource("");
+    String  path = p.getPath().concat(
+        TestOzoneContainer.class.getSimpleName());
+    path += conf.getTrimmed(OzoneConfigKeys.DFS_STORAGE_LOCAL_ROOT,
+        OzoneConfigKeys.DFS_STORAGE_LOCAL_ROOT_DEFAULT);
+    conf.set(OzoneConfigKeys.DFS_STORAGE_LOCAL_ROOT, path);
+
+    // Start ozone container Via Datanode create.
+    conf.setBoolean(OzoneConfigKeys.DFS_OBJECTSTORE_ENABLED_KEY, true);
+    conf.set(OzoneConfigKeys.DFS_STORAGE_HANDLER_TYPE_KEY, "local");
+
+    Pipeline pipeline = ContainerTestHelper.createSingleNodePipeline();
+    conf.setInt(OzoneConfigKeys.DFS_OZONE_CONTAINER_IPC_PORT,
+        pipeline.getLeader().getContainerPort());
+
+    MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
+    cluster.waitActive();
+
+    // This client talks to ozone container via datanode.
+    XceiverClient client = new XceiverClient(pipeline, conf);
+    client.connect();
+    ContainerProtos.ContainerCommandRequestProto request =
+        ContainerTestHelper.getCreateContainerRequest();
+    ContainerProtos.ContainerCommandResponseProto response =
+        client.sendCommand(request);
+    Assert.assertNotNull(response);
+    Assert.assertTrue(request.getTraceID().equals(response.getTraceID()));
+    cluster.shutdown();
+
+  }
+
+}

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

@@ -22,7 +22,7 @@ package org.apache.hadoop.ozone.web;
 import org.apache.hadoop.fs.StorageType;
 import org.apache.hadoop.ozone.web.request.OzoneAcl;
 import org.apache.hadoop.ozone.web.response.BucketInfo;
-import org.apache.hadoop.ozone.web.utils.OzoneConsts;
+import org.apache.hadoop.ozone.OzoneConsts;
 import org.junit.Test;
 
 import java.io.IOException;

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

@@ -23,7 +23,7 @@ import org.apache.hadoop.ozone.OzoneConfigKeys;
 import org.apache.hadoop.ozone.OzoneConfiguration;
 import org.apache.hadoop.ozone.web.exceptions.ErrorTable;
 import org.apache.hadoop.ozone.web.headers.Header;
-import org.apache.hadoop.ozone.web.utils.OzoneConsts;
+import org.apache.hadoop.ozone.OzoneConsts;
 import org.apache.hadoop.ozone.web.utils.OzoneUtils;
 import org.apache.hadoop.util.Time;
 import org.apache.http.HttpResponse;

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

@@ -29,13 +29,12 @@ import java.util.Date;
 import java.util.Locale;
 import javax.ws.rs.core.HttpHeaders;
 
-import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
 import org.apache.hadoop.hdfs.server.datanode.DataNode;
 import org.apache.hadoop.ozone.OzoneConfigKeys;
 import org.apache.hadoop.ozone.OzoneConfiguration;
 import org.apache.hadoop.ozone.web.headers.Header;
-import org.apache.hadoop.ozone.web.utils.OzoneConsts;
+import org.apache.hadoop.ozone.OzoneConsts;
 import org.apache.hadoop.util.Time;
 
 import org.apache.http.HttpResponse;

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/ozone/web/client/TestVolume.java

@@ -24,12 +24,11 @@ import org.apache.hadoop.ozone.OzoneConfigKeys;
 import org.apache.hadoop.ozone.OzoneConfiguration;
 import org.apache.hadoop.ozone.web.exceptions.OzoneException;
 import org.apache.hadoop.ozone.web.request.OzoneQuota;
-import org.apache.hadoop.ozone.web.utils.OzoneConsts;
+import org.apache.hadoop.ozone.OzoneConsts;
 import org.apache.hadoop.ozone.web.utils.OzoneUtils;
 import org.apache.log4j.Level;
 import org.apache.log4j.Logger;
 import org.junit.AfterClass;
-import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;