| /** |
| * 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.protocol; |
| |
| import java.io.IOException; |
| import java.util.List; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.hdfs.DFSConfigKeys; |
| import org.apache.hadoop.hdfs.security.token.block.BlockTokenIdentifier; |
| import org.apache.hadoop.hdfs.security.token.block.BlockTokenSelector; |
| import org.apache.hadoop.security.KerberosInfo; |
| import org.apache.hadoop.security.token.Token; |
| import org.apache.hadoop.security.token.TokenInfo; |
| |
| /** An client-datanode protocol for block recovery |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Evolving |
| @KerberosInfo( |
| serverPrincipal = DFSConfigKeys.DFS_DATANODE_USER_NAME_KEY) |
| @TokenInfo(BlockTokenSelector.class) |
| public interface ClientDatanodeProtocol { |
| /** |
| * Until version 9, this class ClientDatanodeProtocol served as both |
| * the client interface to the DN AND the RPC protocol used to |
| * communicate with the NN. |
| * |
| * This class is used by both the DFSClient and the |
| * DN server side to insulate from the protocol serialization. |
| * |
| * If you are adding/changing DN's interface then you need to |
| * change both this class and ALSO related protocol buffer |
| * wire protocol definition in ClientDatanodeProtocol.proto. |
| * |
| * For more details on protocol buffer wire protocol, please see |
| * .../org/apache/hadoop/hdfs/protocolPB/overview.html |
| * |
| * The log of historical changes can be retrieved from the svn). |
| * 9: Added deleteBlockPool method |
| * |
| * 9 is the last version id when this class was used for protocols |
| * serialization. DO not update this version any further. |
| */ |
| public static final long versionID = 9L; |
| |
| /** Return the visible length of a replica. */ |
| long getReplicaVisibleLength(ExtendedBlock b) throws IOException; |
| |
| /** |
| * Refresh the list of federated namenodes from updated configuration |
| * Adds new namenodes and stops the deleted namenodes. |
| * |
| * @throws IOException on error |
| **/ |
| void refreshNamenodes() throws IOException; |
| |
| /** |
| * Delete the block pool directory. If force is false it is deleted only if |
| * it is empty, otherwise it is deleted along with its contents. |
| * |
| * @param bpid Blockpool id to be deleted. |
| * @param force If false blockpool directory is deleted only if it is empty |
| * i.e. if it doesn't contain any block files, otherwise it is |
| * deleted along with its contents. |
| * @throws IOException |
| */ |
| void deleteBlockPool(String bpid, boolean force) throws IOException; |
| |
| /** |
| * Retrieves the path names of the block file and metadata file stored on the |
| * local file system. |
| * |
| * In order for this method to work, one of the following should be satisfied: |
| * <ul> |
| * <li> |
| * The client user must be configured at the datanode to be able to use this |
| * method.</li> |
| * <li> |
| * When security is enabled, kerberos authentication must be used to connect |
| * to the datanode.</li> |
| * </ul> |
| * |
| * @param block |
| * the specified block on the local datanode |
| * @param token |
| * the block access token. |
| * @return the BlockLocalPathInfo of a block |
| * @throws IOException |
| * on error |
| */ |
| BlockLocalPathInfo getBlockLocalPathInfo(ExtendedBlock block, |
| Token<BlockTokenIdentifier> token) throws IOException; |
| |
| /** |
| * Retrieves volume location information about a list of blocks on a datanode. |
| * This is in the form of an opaque {@link VolumeId} for each configured |
| * data directory, which is not guaranteed to be the same across DN restarts. |
| * |
| * @param blocks |
| * list of blocks on the local datanode |
| * @param tokens |
| * block access tokens corresponding to the requested blocks |
| * @return an HdfsBlocksMetadata that associates {@link ExtendedBlock}s with |
| * data directories |
| * @throws IOException |
| * if datanode is unreachable, or replica is not found on datanode |
| */ |
| HdfsBlocksMetadata getHdfsBlocksMetadata(List<ExtendedBlock> blocks, |
| List<Token<BlockTokenIdentifier>> tokens) throws IOException; |
| } |