org.apache.hadoop.hdfs.server.protocol.InterDatanodeProtocol Maven / Gradle / Ivy
/**
* 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.server.protocol;
import java.io.IOException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
import org.apache.hadoop.hdfs.server.protocol.BlockRecoveryCommand.RecoveringBlock;
import org.apache.hadoop.security.KerberosInfo;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/** An inter-datanode protocol for updating generation stamp
*/
@KerberosInfo(
serverPrincipal = DFSConfigKeys.DFS_DATANODE_KERBEROS_PRINCIPAL_KEY,
clientPrincipal = DFSConfigKeys.DFS_DATANODE_KERBEROS_PRINCIPAL_KEY)
@InterfaceAudience.Private
public interface InterDatanodeProtocol {
Logger LOG = LoggerFactory.getLogger(InterDatanodeProtocol.class.getName());
/**
* Until version 9, this class InterDatanodeProtocol served as both
* the interface to the DN AND the RPC protocol used to communicate with the
* DN.
*
* This class is used by both the DN 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 InterDatanodeProtocol.proto.
*
* For more details on protocol buffer wire protocol, please see
* .../org/apache/hadoop/hdfs/protocolPB/overview.html
*/
public static final long versionID = 6L;
/**
* Initialize a replica recovery.
*
* @return actual state of the replica on this data-node or
* null if data-node does not have the replica.
*/
ReplicaRecoveryInfo initReplicaRecovery(RecoveringBlock rBlock)
throws IOException;
/**
* Update replica with the new generation stamp and length.
*/
String updateReplicaUnderRecovery(ExtendedBlock oldBlock, long recoveryId,
long newBlockId, long newLength)
throws IOException;
}