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* 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.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.ReconfigurationTaskStatus;
import org.apache.hadoop.hdfs.client.BlockReportOptions;
import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
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;
import org.apache.hadoop.hdfs.server.datanode.DiskBalancerWorkStatus;
/** An client-datanode protocol for block recovery
*/
@InterfaceAudience.Private
@InterfaceStability.Evolving
@KerberosInfo(
serverPrincipal = HdfsClientConfigKeys.DFS_DATANODE_KERBEROS_PRINCIPAL_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.
*/
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:
*
* -
* The client user must be configured at the datanode to be able to use this
* method.
* -
* When security is enabled, kerberos authentication must be used to connect
* to the datanode.
*
*
* @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 token) throws IOException;
/**
* Shuts down a datanode.
*
* @param forUpgrade If true, data node does extra prep work before shutting
* down. The work includes advising clients to wait and saving
* certain states for quick restart. This should only be used when
* the stored data will remain the same during upgrade/restart.
* @throws IOException
*/
void shutdownDatanode(boolean forUpgrade) throws IOException;
/**
* Evict clients that are writing to a datanode.
*
* @throws IOException
*/
void evictWriters() throws IOException;
/**
* Obtains datanode info
*
* @return software/config version and uptime of the datanode
*/
DatanodeLocalInfo getDatanodeInfo() throws IOException;
/**
* Asynchronously reload configuration on disk and apply changes.
*/
void startReconfiguration() throws IOException;
/**
* Get the status of the previously issued reconfig task.
* @see org.apache.hadoop.conf.ReconfigurationTaskStatus
*/
ReconfigurationTaskStatus getReconfigurationStatus() throws IOException;
/**
* Get a list of allowed properties for reconfiguration.
*/
List listReconfigurableProperties() throws IOException;
/**
* Trigger a new block report.
*/
void triggerBlockReport(BlockReportOptions options)
throws IOException;
/**
* Get current value of the balancer bandwidth in bytes per second.
*
* @return balancer bandwidth
*/
long getBalancerBandwidth() throws IOException;
/**
* Get volume report of datanode.
*/
List getVolumeReport() throws IOException;
/**
* Submit a disk balancer plan for execution.
*/
void submitDiskBalancerPlan(String planID, long planVersion, String planFile,
String planData, boolean skipDateCheck)
throws IOException;
/**
* Cancel an executing plan.
*
* @param planID - A SHA-1 hash of the plan string.
*/
void cancelDiskBalancePlan(String planID) throws IOException;
/**
* Gets the status of an executing diskbalancer Plan.
*/
DiskBalancerWorkStatus queryDiskBalancerPlan() throws IOException;
/**
* Gets a run-time configuration value from running diskbalancer instance.
* For example : Disk Balancer bandwidth of a running instance.
*
* @param key runtime configuration key
* @return value of the key as a string.
* @throws IOException - Throws if there is no such key
*/
String getDiskBalancerSetting(String key) throws IOException;
}