/**
* 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 org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.ipc.VersionedProtocol;
/** An client-datanode protocol for block recovery
*/
public interface ClientDatanodeProtocol extends VersionedProtocol {
public static final Log LOG = LogFactory.getLog(ClientDatanodeProtocol.class);
public static final long GET_BLOCKINFO_VERSION = 4L;
public static final long COPY_BLOCK_VERSION = 5L;
/**
* 3: add keepLength parameter.
* 4: added getBlockInfo
* 5: add copyBlock parameter.
*/
public static final long versionID = 5L;
/** Start generation-stamp recovery for specified block
* @param block the specified block
* @param keepLength keep the block length
* @param targets the list of possible locations of specified block
* @return the new blockid if recovery successful and the generation stamp
* got updated as part of the recovery, else returns null if the block id
* not have any data and the block was deleted.
* @throws IOException
*/
LocatedBlock recoverBlock(Block block, boolean keepLength,
DatanodeInfo[] targets) throws IOException;
/** Start generation-stamp recovery for specified block
* @param namespaceid the block belongs to
* @param block the specified block
* @param keepLength keep the block length
* @param targets the list of possible locations of specified block
* @return the new blockid if recovery successful and the generation stamp
* got updated as part of the recovery, else returns null if the block id
* not have any data and the block was deleted.
* @throws IOException
*/
LocatedBlock recoverBlock(int namespaceId, Block block, boolean keepLength,
DatanodeInfo[] targets) throws IOException;
/** Start generation-stamp recovery for specified block
* @param namespaceid the block belongs to
* @param block the specified block
* @param keepLength keep the block length
* @param targets the list of possible locations of specified block
* @param deadline after it, RPC should terminate
* @return the new blockid if recovery successful and the generation stamp
* got updated as part of the recovery, else returns null if the block id
* not have any data and the block was deleted.
* @throws IOException
*/
LocatedBlock recoverBlock(int namespaceId, Block block, boolean keepLength,
DatanodeInfo[] targets, long deadline) throws IOException;
/** Returns a block object that contains the specified block object
* from the specified Datanode.
* @param block the specified block
* @return the Block object from the specified Datanode
* @throws IOException if the block does not exist
*/
public Block getBlockInfo(Block block) throws IOException;
/** Returns a block object that contains the specified block object
* from the specified Datanode.
* @param namespaceid the block belongs to
* @param block the specified block
* @return the Block object from the specified Datanode
* @throws IOException if the block does not exist
*/
public Block getBlockInfo(int namespaceid, Block block) throws IOException;
/** Instruct the datanode to copy a block to specified target.
* @param srcBlock the specified block on this datanode
* @param destinationBlock the block identifier on the destination datanode
* @param target the locations where this block needs to be copied
* @throws IOException
*/
public void copyBlock(Block srcblock, Block destBlock,
DatanodeInfo target) throws IOException;
/** Instruct the datanode to copy a block to specified target.
* @param srcNamespaceId the namespaceId of srcBlock
* @param srcBlock the specified block on this datanode
* @param dstNamespaceId the namespace id of dstBlock
* @param destinationBlock the block identifier on the destination datanode
* @param target the locations where this block needs to be copied
* @throws IOException
*/
public void copyBlock(int srcNamespaceId, Block srcblock,
int dstNamespaceId, Block destBlock,
DatanodeInfo target) throws IOException;
/** Instruct the datanode to copy a block to specified target.
* @param srcBlock the specified block on this datanode
* @param destinationBlock the block identifier on the destination datanode
* @param target the locations where this block needs to be copied
* @param async whether or not the call should block till the block is completely copied.
* @throws IOException
*/
public void copyBlock(Block srcblock, Block destBlock,
DatanodeInfo target, boolean async) throws IOException;
/** Instruct the datanode to copy a block to specified target.
* @param srcNamespaceId the namespace source block belongs to
* @param srcBlock the specified block on this datanode
* @param dstNamespaceId the namespace destination block belongs to
* @param destinationBlock the block identifier on the destination datanode
* @param target the locations where this block needs to be copied
* @param async if wait for block copy done or not
* @throws IOException
*/
public void copyBlock(int srcNamespaceId, Block srcblock,
int dstNamespaceId, Block destBlock,
DatanodeInfo target, boolean async) throws IOException;
/** Retrives the filename of the blockfile and the metafile from the datanode
* @param namespaceid the block belongs to
* @param block the specified block on this datanode
* @return the BlockPathInfo of a block
*/
BlockPathInfo getBlockPathInfo(Block block) throws IOException;
/** Retrives the filename of the blockfile and the metafile from the datanode
* @param block the specified block on this datanode
* @return the BlockPathInfo of a block
*/
BlockPathInfo getBlockPathInfo(int namespaceId, Block block) throws IOException;
/** Refresh name nodes served by the datanode
* datanode reloads the configuration file and stops serving removed namenodes and
* starts serving newly-added namenodes
* @throws IOException
*/
public void refreshNamenodes() throws IOException;
/**
* @param serviceName service's name to refresh.
*/
public void refreshOfferService(String serviceName) throws IOException;
/**
* Informs the datanode it should stop serving the given namespace.
* @param nameserviceId the id of the namespace the datanode should stop
* serving
* @throws IOEXception
*/
public void removeNamespace(String nameserviceId) throws IOException;
/** Reads in data dirs from a textfile containing these directories
* datanode will refresh the configuration file with the new list
* of directories
* @throws IOException
*/
public void refreshDataDirs(String confVolumes) throws IOException;
}