Package org.apache.hadoop.hdfs.server.federation.resolver

Class MountTableResolver

java.lang.Object

org.apache.hadoop.hdfs.server.federation.resolver.MountTableResolver

All Implemented Interfaces:

FileSubclusterResolver, StateStoreCache

Direct Known Subclasses:

MultipleDestinationMountTableResolver

public class MountTableResolver
extends java.lang.Object
implements FileSubclusterResolver, StateStoreCache

Mount table to map between global paths and remote locations. This allows the Router to map the global HDFS view to the remote namespaces. This is similar to ViewFs. This is implemented as a tree.

Constructor Summary

Constructors

Constructor	Description
MountTableResolver(org.apache.hadoop.conf.Configuration conf)
MountTableResolver(org.apache.hadoop.conf.Configuration conf, Router routerService)
MountTableResolver(org.apache.hadoop.conf.Configuration conf, Router routerService, StateStoreService store)
MountTableResolver(org.apache.hadoop.conf.Configuration conf, StateStoreService store)

Method Summary

Modifier and Type	Method	Description
void	addEntry(MountTable entry)	Add a mount entry to the table.
void	clear()	Clears all data.
protected long	getCacheSize()	Get the size of the cache.
java.lang.String	getDefaultNameService()
java.lang.String	getDefaultNamespace()	Get the default namespace for the cluster.
PathLocation	getDestinationForPath(java.lang.String path)	Get the destinations for a global path.
java.util.concurrent.atomic.LongAdder	getLocCacheAccess()
java.util.concurrent.atomic.LongAdder	getLocCacheMiss()
MountTable	getMountPoint(java.lang.String path)	Get the mount table entry for a path.
java.util.List<java.lang.String>	getMountPoints(java.lang.String str)	Get a list of mount points for a path.
java.util.List<MountTable>	getMounts(java.lang.String path)	Get all the mount records at or beneath a given path.
protected MountTableStore	getMountTableStore()	Get the mount table store for this resolver.
protected Router	getRouter()	Get a reference for the Router for this resolver.
static java.lang.String	getTrashRoot()
boolean	isDefaultNSEnable()
static boolean	isTrashPath(java.lang.String path)	Check if path is the trail associated with the Trash.
boolean	loadCache(boolean force)	Replaces the current in-memory cached of the mount table with a new version fetched from the data store.
PathLocation	lookupLocation(java.lang.String str)	Build the path location to insert into the cache atomically.
void	refreshEntries(java.util.Collection<MountTable> entries)	Updates the mount path tree with a new set of mount table entries.
void	removeEntry(java.lang.String srcPath)	Remove a mount table entry.
void	setDefaultNameService(java.lang.String defaultNameService)
void	setDefaultNSEnable(boolean defaultNSRWEnable)
void	setDisabled(boolean disable)
static java.lang.String	subtractTrashCurrentPath(java.lang.String path)	Subtract a TrashCurrent to get a new path.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

MountTableResolver

@VisibleForTesting
public MountTableResolver(org.apache.hadoop.conf.Configuration conf)

MountTableResolver

public MountTableResolver(org.apache.hadoop.conf.Configuration conf,
                          Router routerService)

MountTableResolver

public MountTableResolver(org.apache.hadoop.conf.Configuration conf,
                          StateStoreService store)

MountTableResolver

public MountTableResolver(org.apache.hadoop.conf.Configuration conf,
                          Router routerService,
                          StateStoreService store)

Method Detail

getRouter

protected Router getRouter()

Get a reference for the Router for this resolver.

Returns:

Router for this resolver.

getMountTableStore

protected MountTableStore getMountTableStore()
                                      throws java.io.IOException

Get the mount table store for this resolver.

Returns:

Mount table store.

Throws:

java.io.IOException - If it cannot connect to the State Store.

addEntry

public void addEntry(MountTable entry)

Add a mount entry to the table.

Parameters:

entry - The mount table record to add from the state store.

removeEntry

public void removeEntry(java.lang.String srcPath)

Remove a mount table entry.

Parameters:

srcPath - Source path for the entry to remove.

refreshEntries

@VisibleForTesting
public void refreshEntries(java.util.Collection<MountTable> entries)

Updates the mount path tree with a new set of mount table entries. It also updates the needed caches.

Parameters:

entries - Full set of mount table entries to update.

isTrashPath

@VisibleForTesting
public static boolean isTrashPath(java.lang.String path)
                           throws java.io.IOException

Check if path is the trail associated with the Trash.

Parameters:

path - a path.

Returns:

true if the path matches the trash path pattern, false otherwise.

Throws:

java.io.IOException - if retrieving current user's trash directory fails.

getTrashRoot

@VisibleForTesting
public static java.lang.String getTrashRoot()
                                     throws java.io.IOException

Throws:

java.io.IOException

subtractTrashCurrentPath

@VisibleForTesting
public static java.lang.String subtractTrashCurrentPath(java.lang.String path)
                                                 throws java.io.IOException

Subtract a TrashCurrent to get a new path.

Parameters:

path - a path.

Returns:

new path with subtracted trash current path.

Throws:

java.io.IOException - if retrieving current user's trash directory fails.

loadCache

public boolean loadCache(boolean force)

Replaces the current in-memory cached of the mount table with a new version fetched from the data store.

Specified by:

loadCache in interface StateStoreCache

Parameters:

force - If we force the load.

Returns:

If the cache was loaded successfully.

clear

public void clear()

Clears all data.

getDestinationForPath

public PathLocation getDestinationForPath(java.lang.String path)
                                   throws java.io.IOException

Description copied from interface: FileSubclusterResolver

Get the destinations for a global path. Results are from the mount table cache. If multiple destinations are available, the first result is the highest priority destination.

Specified by:

getDestinationForPath in interface FileSubclusterResolver

Parameters:

path - Global path.

Returns:

Location in a destination namespace or null if it does not exist.

Throws:

java.io.IOException - Throws exception if the data is not available.

lookupLocation

public PathLocation lookupLocation(java.lang.String str)
                            throws java.io.IOException

Build the path location to insert into the cache atomically. It must hold the read lock.

Parameters:

str - Path to check/insert.

Returns:

New remote location.

Throws:

java.io.IOException - If it cannot find the location.

getMountPoint

public MountTable getMountPoint(java.lang.String path)
                         throws java.io.IOException

Get the mount table entry for a path.

Parameters:

path - Path to look for.

Returns:

Mount table entry the path belongs.

Throws:

java.io.IOException - If the State Store could not be reached.

getMountPoints

public java.util.List<java.lang.String> getMountPoints(java.lang.String str)
                                                throws java.io.IOException

Description copied from interface: FileSubclusterResolver

Get a list of mount points for a path. Results are from the mount table cache.

Specified by:

getMountPoints in interface FileSubclusterResolver

Parameters:

str - Path to get the mount points under.

Returns:

List of mount points present at this path. Return zero-length list if the path is a mount point but there are no mount points under the path. Return null if the path is not a mount point and there are no mount points under the path.

Throws:

java.io.IOException - Throws exception if the data is not available.

getMounts

public java.util.List<MountTable> getMounts(java.lang.String path)
                                     throws java.io.IOException

Get all the mount records at or beneath a given path.

Parameters:

path - Path to get the mount points from.

Returns:

List of mount table records under the path or null if the path is not found.

Throws:

java.io.IOException - If it's not connected to the State Store.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getDefaultNamespace

public java.lang.String getDefaultNamespace()

Description copied from interface: FileSubclusterResolver

Get the default namespace for the cluster.

Specified by:

getDefaultNamespace in interface FileSubclusterResolver

Returns:

Default namespace identifier.

getCacheSize

protected long getCacheSize()
                     throws java.io.IOException

Get the size of the cache.

Returns:

Size of the cache.

Throws:

java.io.IOException - If the cache is not initialized.

getDefaultNameService

@VisibleForTesting
public java.lang.String getDefaultNameService()

setDefaultNameService

@VisibleForTesting
public void setDefaultNameService(java.lang.String defaultNameService)

isDefaultNSEnable

@VisibleForTesting
public boolean isDefaultNSEnable()

setDefaultNSEnable

@VisibleForTesting
public void setDefaultNSEnable(boolean defaultNSRWEnable)

setDisabled

@VisibleForTesting
public void setDisabled(boolean disable)

getLocCacheMiss

public java.util.concurrent.atomic.LongAdder getLocCacheMiss()

getLocCacheAccess

public java.util.concurrent.atomic.LongAdder getLocCacheAccess()