Package org.apache.hadoop.hdfs.protocol

Class HdfsConstants

java.lang.Object

org.apache.hadoop.hdfs.protocol.HdfsConstants

@Private
public final class HdfsConstants
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	HdfsConstants.DatanodeReportType
static enum	HdfsConstants.ReencryptAction	Re-encrypt encryption zone actions.
static enum	HdfsConstants.RollingUpgradeAction
static enum	HdfsConstants.SafeModeAction
static enum	HdfsConstants.StoragePolicy	This enum wraps above Storage Policy ID and name.
static enum	HdfsConstants.StoragePolicySatisfierMode	Storage policy satisfier service modes.
static enum	HdfsConstants.UpgradeAction	Upgrade actions.

Field Summary

Fields

Modifier and Type	Field	Description
static final byte	ALLNVDIMM_STORAGE_POLICY_ID
static final String	ALLNVDIMM_STORAGE_POLICY_NAME
static final byte	ALLSSD_STORAGE_POLICY_ID
static final String	ALLSSD_STORAGE_POLICY_NAME
static final byte	BLOCK_STORAGE_POLICY_ID_UNSPECIFIED
static final int	BYTES_IN_INTEGER
static final String	CLIENT_NAMENODE_PROTOCOL_NAME	HDFS Protocol Names:
static final byte	COLD_STORAGE_POLICY_ID
static final String	COLD_STORAGE_POLICY_NAME
static final int	DEFAULT_DATA_SOCKET_SIZE
static final String	DOT_INODES_STRING
static final String	DOT_RESERVED_PATH_PREFIX
static final String	DOT_RESERVED_STRING
static final String	DOT_SNAPSHOT_DIR	A special path component contained in the path for a snapshot file/dir
static final String	DOT_SNAPSHOT_DIR_SEPARATOR
static final long	GRANDFATHER_GENERATION_STAMP	Generation stamp of blocks that pre-date the introduction of a generation stamp.
static final long	GRANDFATHER_INODE_ID	The inode id validation of lease check will be skipped when the request uses GRANDFATHER_INODE_ID for backward compatibility.
static final String	HA_DT_SERVICE_PREFIX	A prefix put before the namenode URI inside the "service" field of a delgation token, indicating that the URI is a logical (HA) URI.
static final String	HDFS_URI_SCHEME	URI Scheme for hdfs://namenode/ URIs.
static final byte	HOT_STORAGE_POLICY_ID
static final String	HOT_STORAGE_POLICY_NAME
static final long	LEASE_SOFTLIMIT_PERIOD	For a HDFS client to write to a file, a lease is granted; During the lease period, no other client can write to the file.
static final byte	MEMORY_STORAGE_POLICY_ID
static final String	MEMORY_STORAGE_POLICY_NAME
static final byte	ONESSD_STORAGE_POLICY_ID
static final String	ONESSD_STORAGE_POLICY_NAME
static final byte	PROVIDED_STORAGE_POLICY_ID
static final String	PROVIDED_STORAGE_POLICY_NAME
static final long	QUOTA_DONT_SET
static final long	QUOTA_RESET
static final int	READ_TIMEOUT
static final int	READ_TIMEOUT_EXTENSION
static final String	ROUTER_ADMIN_PROTOCOL_NAME	Router admin Protocol Names.
static final String	SAFEMODE_EXCEPTION_CLASS_NAME
static final String	SEPARATOR_DOT_SNAPSHOT_DIR
static final String	SEPARATOR_DOT_SNAPSHOT_DIR_SEPARATOR
static final byte	WARM_STORAGE_POLICY_ID
static final String	WARM_STORAGE_POLICY_NAME
static final int	WRITE_TIMEOUT
static final int	WRITE_TIMEOUT_EXTENSION

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	HdfsConstants()

Method Summary

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

QUOTA_DONT_SET

public static final long QUOTA_DONT_SET

See Also:

• Constant Field Values

QUOTA_RESET

public static final long QUOTA_RESET

See Also:

• Constant Field Values

BYTES_IN_INTEGER

public static final int BYTES_IN_INTEGER

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• Constant Field Values

HDFS_URI_SCHEME

public static final String HDFS_URI_SCHEME

URI Scheme for hdfs://namenode/ URIs.

See Also:

• Constant Field Values

MEMORY_STORAGE_POLICY_ID

public static final byte MEMORY_STORAGE_POLICY_ID

See Also:

• Constant Field Values

MEMORY_STORAGE_POLICY_NAME

public static final String MEMORY_STORAGE_POLICY_NAME

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ALLNVDIMM_STORAGE_POLICY_ID

public static final byte ALLNVDIMM_STORAGE_POLICY_ID

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ALLNVDIMM_STORAGE_POLICY_NAME

public static final String ALLNVDIMM_STORAGE_POLICY_NAME

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ALLSSD_STORAGE_POLICY_ID

public static final byte ALLSSD_STORAGE_POLICY_ID

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ALLSSD_STORAGE_POLICY_NAME

public static final String ALLSSD_STORAGE_POLICY_NAME

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ONESSD_STORAGE_POLICY_ID

public static final byte ONESSD_STORAGE_POLICY_ID

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ONESSD_STORAGE_POLICY_NAME

public static final String ONESSD_STORAGE_POLICY_NAME

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HOT_STORAGE_POLICY_ID

public static final byte HOT_STORAGE_POLICY_ID

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HOT_STORAGE_POLICY_NAME

public static final String HOT_STORAGE_POLICY_NAME

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WARM_STORAGE_POLICY_ID

public static final byte WARM_STORAGE_POLICY_ID

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• Constant Field Values

WARM_STORAGE_POLICY_NAME

public static final String WARM_STORAGE_POLICY_NAME

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• Constant Field Values

COLD_STORAGE_POLICY_ID

public static final byte COLD_STORAGE_POLICY_ID

See Also:

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COLD_STORAGE_POLICY_NAME

public static final String COLD_STORAGE_POLICY_NAME

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PROVIDED_STORAGE_POLICY_ID

public static final byte PROVIDED_STORAGE_POLICY_ID

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PROVIDED_STORAGE_POLICY_NAME

public static final String PROVIDED_STORAGE_POLICY_NAME

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• Constant Field Values

DEFAULT_DATA_SOCKET_SIZE

public static final int DEFAULT_DATA_SOCKET_SIZE

See Also:

• Constant Field Values

DOT_SNAPSHOT_DIR

public static final String DOT_SNAPSHOT_DIR

A special path component contained in the path for a snapshot file/dir

See Also:

• Constant Field Values

SEPARATOR_DOT_SNAPSHOT_DIR

public static final String SEPARATOR_DOT_SNAPSHOT_DIR

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DOT_SNAPSHOT_DIR_SEPARATOR

public static final String DOT_SNAPSHOT_DIR_SEPARATOR

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SEPARATOR_DOT_SNAPSHOT_DIR_SEPARATOR

public static final String SEPARATOR_DOT_SNAPSHOT_DIR_SEPARATOR

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DOT_RESERVED_STRING

public static final String DOT_RESERVED_STRING

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DOT_RESERVED_PATH_PREFIX

public static final String DOT_RESERVED_PATH_PREFIX

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DOT_INODES_STRING

public static final String DOT_INODES_STRING

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• Constant Field Values

GRANDFATHER_GENERATION_STAMP

public static final long GRANDFATHER_GENERATION_STAMP

Generation stamp of blocks that pre-date the introduction of a generation stamp.

See Also:

• Constant Field Values

GRANDFATHER_INODE_ID

public static final long GRANDFATHER_INODE_ID

The inode id validation of lease check will be skipped when the request uses GRANDFATHER_INODE_ID for backward compatibility.

See Also:

• Constant Field Values

BLOCK_STORAGE_POLICY_ID_UNSPECIFIED

public static final byte BLOCK_STORAGE_POLICY_ID_UNSPECIFIED

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• Constant Field Values

HA_DT_SERVICE_PREFIX

public static final String HA_DT_SERVICE_PREFIX

A prefix put before the namenode URI inside the "service" field of a delgation token, indicating that the URI is a logical (HA) URI.

See Also:

• Constant Field Values

SAFEMODE_EXCEPTION_CLASS_NAME

public static final String SAFEMODE_EXCEPTION_CLASS_NAME

See Also:

• Constant Field Values

CLIENT_NAMENODE_PROTOCOL_NAME

public static final String CLIENT_NAMENODE_PROTOCOL_NAME

HDFS Protocol Names:

See Also:

• Constant Field Values

ROUTER_ADMIN_PROTOCOL_NAME

public static final String ROUTER_ADMIN_PROTOCOL_NAME

Router admin Protocol Names.

See Also:

• Constant Field Values

READ_TIMEOUT

public static final int READ_TIMEOUT

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READ_TIMEOUT_EXTENSION

public static final int READ_TIMEOUT_EXTENSION

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WRITE_TIMEOUT

public static final int WRITE_TIMEOUT

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WRITE_TIMEOUT_EXTENSION

public static final int WRITE_TIMEOUT_EXTENSION

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• Constant Field Values

LEASE_SOFTLIMIT_PERIOD

public static final long LEASE_SOFTLIMIT_PERIOD

For a HDFS client to write to a file, a lease is granted; During the lease period, no other client can write to the file. The writing client can periodically renew the lease. When the file is closed, the lease is revoked. The lease duration is bound by this soft limit and a HdfsClientConfigKeys.DFS_LEASE_HARDLIMIT_KEY. Until the soft limit expires, the writer has sole write access to the file. If the soft limit expires and the client fails to close the file or renew the lease, another client can preempt the lease.

See Also:

• Constant Field Values

Constructor Details

HdfsConstants

protected HdfsConstants()