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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.util.HashMap;
import java.util.Map;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.DFSUtil;
import org.apache.hadoop.hdfs.HdfsConfiguration;
import org.apache.hadoop.hdfs.server.namenode.FSDirectory;
import org.apache.hadoop.hdfs.server.datanode.DataNode;
import org.apache.hadoop.hdfs.server.datanode.DataNodeLayoutVersion;
import org.apache.hadoop.hdfs.server.namenode.NameNode;
import org.apache.hadoop.hdfs.server.namenode.NameNodeLayoutVersion;
import org.apache.hadoop.util.StringUtils;
/************************************
* Some handy constants
*
************************************/
@InterfaceAudience.Private
public class HdfsConstants {
/* Hidden constructor */
protected HdfsConstants() {
}
/**
* HDFS Protocol Names:
*/
public static final String CLIENT_NAMENODE_PROTOCOL_NAME =
"org.apache.hadoop.hdfs.protocol.ClientProtocol";
public static final String CLIENT_DATANODE_PROTOCOL_NAME =
"org.apache.hadoop.hdfs.protocol.ClientDatanodeProtocol";
public static final int MIN_BLOCKS_FOR_WRITE = 1;
// Long that indicates "leave current quota unchanged"
public static final long QUOTA_DONT_SET = Long.MAX_VALUE;
public static final long QUOTA_RESET = -1L;
//
// Timeouts, constants
//
public static final long LEASE_SOFTLIMIT_PERIOD = 60 * 1000;
public static final long LEASE_HARDLIMIT_PERIOD = 60 * LEASE_SOFTLIMIT_PERIOD;
public static final long LEASE_RECOVER_PERIOD = 10 * 1000; // in ms
// We need to limit the length and depth of a path in the filesystem.
// HADOOP-438
// Currently we set the maximum length to 8k characters and the maximum depth
// to 1k.
public static final int MAX_PATH_LENGTH = 8000;
public static final int MAX_PATH_DEPTH = 1000;
// TODO should be conf injected?
public static final int DEFAULT_DATA_SOCKET_SIZE = 128 * 1024;
public static final int IO_FILE_BUFFER_SIZE = new HdfsConfiguration().getInt(
DFSConfigKeys.IO_FILE_BUFFER_SIZE_KEY,
DFSConfigKeys.IO_FILE_BUFFER_SIZE_DEFAULT);
// Used for writing header etc.
public static final int SMALL_BUFFER_SIZE = Math.min(IO_FILE_BUFFER_SIZE / 2,
512);
public static final int BYTES_IN_INTEGER = Integer.SIZE / Byte.SIZE;
// SafeMode actions
public static enum SafeModeAction {
SAFEMODE_LEAVE, SAFEMODE_ENTER, SAFEMODE_GET;
}
public static enum RollingUpgradeAction {
QUERY, PREPARE, FINALIZE;
private static final Map MAP
= new HashMap();
static {
MAP.put("", QUERY);
for(RollingUpgradeAction a : values()) {
MAP.put(a.name(), a);
}
}
/** Covert the given String to a RollingUpgradeAction. */
public static RollingUpgradeAction fromString(String s) {
return MAP.get(StringUtils.toUpperCase(s));
}
}
// type of the datanode report
public static enum DatanodeReportType {
ALL, LIVE, DEAD, DECOMMISSIONING
}
// An invalid transaction ID that will never be seen in a real namesystem.
public static final long INVALID_TXID = -12345;
// Number of generation stamps reserved for legacy blocks.
public static final long RESERVED_GENERATION_STAMPS_V1 =
1024L * 1024 * 1024 * 1024;
/**
* URI Scheme for hdfs://namenode/ URIs.
*/
public static final String HDFS_URI_SCHEME = "hdfs";
/**
* A prefix put before the namenode URI inside the "service" field
* of a delgation token, indicating that the URI is a logical (HA)
* URI.
*/
public static final String HA_DT_SERVICE_PREFIX = "ha-";
/**
* Path components that are reserved in HDFS.
*
* .reserved is only reserved under root ("/").
*/
public static final String[] RESERVED_PATH_COMPONENTS = new String[] {
HdfsConstants.DOT_SNAPSHOT_DIR,
FSDirectory.DOT_RESERVED_STRING
};
/**
* Current layout version for NameNode.
* Please see {@link NameNodeLayoutVersion.Feature} on adding new layout version.
*/
public static final int NAMENODE_LAYOUT_VERSION
= NameNodeLayoutVersion.CURRENT_LAYOUT_VERSION;
/**
* Current layout version for DataNode.
* Please see {@link DataNodeLayoutVersion.Feature} on adding new layout version.
*/
public static final int DATANODE_LAYOUT_VERSION
= DataNodeLayoutVersion.CURRENT_LAYOUT_VERSION;
/**
* A special path component contained in the path for a snapshot file/dir
*/
public static final String DOT_SNAPSHOT_DIR = ".snapshot";
public static final byte[] DOT_SNAPSHOT_DIR_BYTES
= DFSUtil.string2Bytes(DOT_SNAPSHOT_DIR);
public static final String SEPARATOR_DOT_SNAPSHOT_DIR
= Path.SEPARATOR + DOT_SNAPSHOT_DIR;
public static final String SEPARATOR_DOT_SNAPSHOT_DIR_SEPARATOR
= Path.SEPARATOR + DOT_SNAPSHOT_DIR + Path.SEPARATOR;
public static final String MEMORY_STORAGE_POLICY_NAME = "LAZY_PERSIST";
public static final String ALLSSD_STORAGE_POLICY_NAME = "ALL_SSD";
public static final String ONESSD_STORAGE_POLICY_NAME = "ONE_SSD";
public static final String HOT_STORAGE_POLICY_NAME = "HOT";
public static final String WARM_STORAGE_POLICY_NAME = "WARM";
public static final String COLD_STORAGE_POLICY_NAME = "COLD";
public static final byte MEMORY_STORAGE_POLICY_ID = 15;
public static final byte ALLSSD_STORAGE_POLICY_ID = 12;
public static final byte ONESSD_STORAGE_POLICY_ID = 10;
public static final byte HOT_STORAGE_POLICY_ID = 7;
public static final byte WARM_STORAGE_POLICY_ID = 5;
public static final byte COLD_STORAGE_POLICY_ID = 2;
}