org.apache.hadoop.hdfs.server.datanode.ReplicaInfo Maven / Gradle / Ivy
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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.server.datanode;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URI;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.fs.LocalFileSystem;
import org.apache.hadoop.hdfs.protocol.Block;
import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi;
import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi.ScanInfo;
import org.apache.hadoop.hdfs.server.datanode.fsdataset.LengthInputStream;
import org.apache.hadoop.hdfs.server.protocol.ReplicaRecoveryInfo;
import org.apache.hadoop.util.LightWeightResizableGSet;
/**
* This class is used by datanodes to maintain meta data of its replicas.
* It provides a general interface for meta information of a replica.
*/
@InterfaceAudience.Private
abstract public class ReplicaInfo extends Block
implements Replica, LightWeightResizableGSet.LinkedElement {
/** For implementing {@link LightWeightResizableGSet.LinkedElement}. */
private LightWeightResizableGSet.LinkedElement next;
/** volume where the replica belongs. */
private FsVolumeSpi volume;
/** This is used by some tests and FsDatasetUtil#computeChecksum. */
private static final FileIoProvider DEFAULT_FILE_IO_PROVIDER =
new FileIoProvider(null, null);
/**
* Constructor.
* @param block a block
* @param vol volume where replica is located
*/
ReplicaInfo(Block block, FsVolumeSpi vol) {
this(vol, block.getBlockId(), block.getNumBytes(),
block.getGenerationStamp());
}
/**
* Constructor
* @param vol volume where replica is located
* @param blockId block id
* @param len replica length
* @param genStamp replica generation stamp
*/
ReplicaInfo(FsVolumeSpi vol, long blockId, long len, long genStamp) {
super(blockId, len, genStamp);
this.volume = vol;
}
/**
* Copy constructor.
* @param from where to copy from
*/
ReplicaInfo(ReplicaInfo from) {
this(from, from.getVolume());
}
/**
* @return the volume where this replica is located on disk
*/
public FsVolumeSpi getVolume() {
return volume;
}
/**
* Get the {@link FileIoProvider} for disk IO operations.
*/
public FileIoProvider getFileIoProvider() {
// In tests and when invoked via FsDatasetUtil#computeChecksum, the
// target volume for this replica may be unknown and hence null.
// Use the DEFAULT_FILE_IO_PROVIDER with no-op hooks.
return (volume != null) ? volume.getFileIoProvider()
: DEFAULT_FILE_IO_PROVIDER;
}
/**
* Set the volume where this replica is located on disk.
*/
void setVolume(FsVolumeSpi vol) {
this.volume = vol;
}
/**
* Get the storageUuid of the volume that stores this replica.
*/
@Override
public String getStorageUuid() {
return volume.getStorageID();
}
/**
* Number of bytes reserved for this replica on disk.
*/
public long getBytesReserved() {
return 0;
}
/**
* Get the {@code URI} for where the data of this replica is stored.
* @return {@code URI} for the location of replica data.
*/
abstract public URI getBlockURI();
/**
* Returns an {@link InputStream} to the replica's data.
* @param seekOffset the offset at which the read is started from.
* @return the {@link InputStream} to read the replica data.
* @throws IOException if an error occurs in opening a stream to the data.
*/
abstract public InputStream getDataInputStream(long seekOffset)
throws IOException;
/**
* Returns an {@link OutputStream} to the replica's data.
* @param append indicates if the block should be opened for append.
* @return the {@link OutputStream} to write to the replica.
* @throws IOException if an error occurs in creating an {@link OutputStream}.
*/
abstract public OutputStream getDataOutputStream(boolean append)
throws IOException;
/**
* @return true if the replica's data exists.
*/
abstract public boolean blockDataExists();
/**
* Used to deletes the replica's block data.
*
* @return true if the replica's data is successfully deleted.
*/
abstract public boolean deleteBlockData();
/**
* @return the length of the block on storage.
*/
abstract public long getBlockDataLength();
/**
* Get the {@code URI} for where the metadata of this replica is stored.
*
* @return {@code URI} for the location of replica metadata.
*/
abstract public URI getMetadataURI();
/**
* Returns an {@link InputStream} to the replica's metadata.
* @param offset the offset at which the read is started from.
* @return the {@link LengthInputStream} to read the replica metadata.
* @throws IOException
*/
abstract public LengthInputStream getMetadataInputStream(long offset)
throws IOException;
/**
* Returns an {@link OutputStream} to the replica's metadata.
* @param append indicates if the block metadata should be opened for append.
* @return the {@link OutputStream} to write to the replica's metadata.
* @throws IOException if an error occurs in creating an {@link OutputStream}.
*/
abstract public OutputStream getMetadataOutputStream(boolean append)
throws IOException;
/**
* @return true if the replica's metadata exists.
*/
abstract public boolean metadataExists();
/**
* Used to deletes the replica's metadata.
*
* @return true if the replica's metadata is successfully deleted.
*/
abstract public boolean deleteMetadata();
/**
* @return the length of the metadata on storage.
*/
abstract public long getMetadataLength();
/**
* Rename the metadata {@link URI} to that referenced by {@code destURI}.
*
* @param destURI the target {@link URI}.
* @return true if the rename is successful.
* @throws IOException if an exception occurs in the rename.
*/
abstract public boolean renameMeta(URI destURI) throws IOException;
/**
* Rename the data {@link URI} to that referenced by {@code destURI}.
*
* @param destURI the target {@link URI}.
* @return true if the rename is successful.
* @throws IOException if an exception occurs in the rename.
*/
abstract public boolean renameData(URI destURI) throws IOException;
/**
* Update this replica with the {@link StorageLocation} found.
* @param replicaLocation the {@link StorageLocation} found for this replica.
*/
abstract public void updateWithReplica(StorageLocation replicaLocation);
/**
* Check whether the block was pinned.
* @param localFS the local filesystem to use.
* @return true if the block is pinned.
* @throws IOException
*/
abstract public boolean getPinning(LocalFileSystem localFS)
throws IOException;
/**
* Set a block to be pinned on this datanode so that it cannot be moved
* by Balancer/Mover.
*
* @param localFS the local filesystem to use.
* @throws IOException if there is an exception in the pinning.
*/
abstract public void setPinning(LocalFileSystem localFS) throws IOException;
/**
* Bump a replica's generation stamp to a new one.
* Its on-disk meta file name is renamed to be the new one too.
*
* @param newGS new generation stamp
* @throws IOException if the change fails
*/
abstract public void bumpReplicaGS(long newGS) throws IOException;
abstract public ReplicaInfo getOriginalReplica();
/**
* Get the recovery id.
* @return the generation stamp that the replica will be bumped to
*/
abstract public long getRecoveryID();
/**
* Set the recovery id.
* @param recoveryId the new recoveryId
*/
abstract public void setRecoveryID(long recoveryId);
abstract public boolean breakHardLinksIfNeeded() throws IOException;
abstract public ReplicaRecoveryInfo createInfo();
abstract public int compareWith(ScanInfo info);
abstract public void truncateBlock(long newLength) throws IOException;
abstract public void copyMetadata(URI destination) throws IOException;
abstract public void copyBlockdata(URI destination) throws IOException;
/**
* Number of bytes originally reserved for this replica. The actual
* reservation is adjusted as data is written to disk.
*
* @return the number of bytes originally reserved for this replica.
*/
public long getOriginalBytesReserved() {
return 0;
}
@Override //Object
public String toString() {
return getClass().getSimpleName()
+ ", " + super.toString()
+ ", " + getState()
+ "\n getNumBytes() = " + getNumBytes()
+ "\n getBytesOnDisk() = " + getBytesOnDisk()
+ "\n getVisibleLength()= " + getVisibleLength()
+ "\n getVolume() = " + getVolume()
+ "\n getBlockURI() = " + getBlockURI();
}
@Override
public boolean isOnTransientStorage() {
return volume.isTransientStorage();
}
@Override
public LightWeightResizableGSet.LinkedElement getNext() {
return next;
}
@Override
public void setNext(LightWeightResizableGSet.LinkedElement next) {
this.next = next;
}
}