org.apache.hadoop.hbase.master
Class TableLockManager

java.lang.Object
  org.apache.hadoop.hbase.master.TableLockManager

Direct Known Subclasses:

TableLockManager.NullTableLockManager

@InterfaceAudience.Private
public abstract class TableLockManager
extends Object

A manager for distributed table level locks.

Nested Class Summary

static class	TableLockManager.NullTableLockManager A null implementation
static interface	TableLockManager.TableLock A distributed lock for a table.

Field Summary

static long	DEFAULT_TABLE_LOCK_EXPIRE_TIMEOUT_MS
protected static long	DEFAULT_TABLE_READ_LOCK_TIMEOUT_MS
protected static long	DEFAULT_TABLE_WRITE_LOCK_TIMEOUT_MS
static String	TABLE_LOCK_ENABLE Configuration key for enabling table-level locks for schema changes
static String	TABLE_LOCK_EXPIRE_TIMEOUT
protected static String	TABLE_READ_LOCK_TIMEOUT_MS Configuration key for time out for trying to acquire table locks
protected static String	TABLE_WRITE_LOCK_TIMEOUT_MS Configuration key for time out for trying to acquire table locks

Constructor Summary

TableLockManager()

Method Summary

static TableLockManager	createTableLockManager(org.apache.hadoop.conf.Configuration conf, ZooKeeperWatcher zkWatcher, ServerName serverName) Creates and returns a TableLockManager according to the configuration
static org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.TableLock	fromBytes(byte[] bytes) Public for hbck
abstract TableLockManager.TableLock	readLock(TableName tableName, String purpose) Returns a TableLock for locking the table for shared access among read-lock holders
abstract void	reapAllExpiredLocks() Force releases all table locks(read and write) that have been held longer than "hbase.table.lock.expire.ms".
abstract void	reapWriteLocks() Force releases table write locks and lock attempts even if this thread does not own the lock.
abstract void	tableDeleted(TableName tableName) Called after a table has been deleted, and after the table lock is released.
abstract void	visitAllLocks(InterProcessLock.MetadataHandler handler) Visits all table locks(read and write), and lock attempts with the given callback MetadataHandler.
abstract TableLockManager.TableLock	writeLock(TableName tableName, String purpose) Returns a TableLock for locking the table for exclusive access

Methods inherited from class java.lang.Object

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

Field Detail

TABLE_LOCK_ENABLE

public static final String TABLE_LOCK_ENABLE

Configuration key for enabling table-level locks for schema changes

See Also:

Constant Field Values

TABLE_WRITE_LOCK_TIMEOUT_MS

protected static final String TABLE_WRITE_LOCK_TIMEOUT_MS

Configuration key for time out for trying to acquire table locks

See Also:

Constant Field Values

TABLE_READ_LOCK_TIMEOUT_MS

protected static final String TABLE_READ_LOCK_TIMEOUT_MS

Configuration key for time out for trying to acquire table locks

See Also:

Constant Field Values

DEFAULT_TABLE_WRITE_LOCK_TIMEOUT_MS

protected static final long DEFAULT_TABLE_WRITE_LOCK_TIMEOUT_MS

See Also:

Constant Field Values

DEFAULT_TABLE_READ_LOCK_TIMEOUT_MS

protected static final long DEFAULT_TABLE_READ_LOCK_TIMEOUT_MS

See Also:

Constant Field Values

TABLE_LOCK_EXPIRE_TIMEOUT

public static final String TABLE_LOCK_EXPIRE_TIMEOUT

See Also:

Constant Field Values

DEFAULT_TABLE_LOCK_EXPIRE_TIMEOUT_MS

public static final long DEFAULT_TABLE_LOCK_EXPIRE_TIMEOUT_MS

See Also:

Constant Field Values

Constructor Detail

TableLockManager

public TableLockManager()

Method Detail

writeLock

public abstract TableLockManager.TableLock writeLock(TableName tableName,
                                                     String purpose)

Returns a TableLock for locking the table for exclusive access

Parameters:

tableName - Table to lock

purpose - Human readable reason for locking the table

Returns:

A new TableLock object for acquiring a write lock

readLock

public abstract TableLockManager.TableLock readLock(TableName tableName,
                                                    String purpose)

Returns a TableLock for locking the table for shared access among read-lock holders

Parameters:

tableName - Table to lock

purpose - Human readable reason for locking the table

Returns:

A new TableLock object for acquiring a read lock

visitAllLocks

public abstract void visitAllLocks(InterProcessLock.MetadataHandler handler)
                            throws IOException

Visits all table locks(read and write), and lock attempts with the given callback MetadataHandler.

Parameters:

handler - the metadata handler to call

Throws:

IOException - If there is an unrecoverable error

reapAllExpiredLocks

public abstract void reapAllExpiredLocks()
                                  throws IOException

Force releases all table locks(read and write) that have been held longer than "hbase.table.lock.expire.ms". Assumption is that the clock skew between zookeeper and this servers is negligible. The behavior of the lock holders still thinking that they have the lock is undefined.

Throws:

IOException - If there is an unrecoverable error

reapWriteLocks

public abstract void reapWriteLocks()
                             throws IOException

Force releases table write locks and lock attempts even if this thread does not own the lock. The behavior of the lock holders still thinking that they have the lock is undefined. This should be used carefully and only when we can ensure that all write-lock holders have died. For example if only the master can hold write locks, then we can reap it's locks when the backup master starts.

Throws:

IOException - If there is an unrecoverable error

tableDeleted

public abstract void tableDeleted(TableName tableName)
                           throws IOException

Called after a table has been deleted, and after the table lock is released. TableLockManager should do cleanup for the table state.

Parameters:

tableName - name of the table

Throws:

IOException - If there is an unrecoverable error releasing the lock

createTableLockManager

public static TableLockManager createTableLockManager(org.apache.hadoop.conf.Configuration conf,
                                                      ZooKeeperWatcher zkWatcher,
                                                      ServerName serverName)

Creates and returns a TableLockManager according to the configuration

fromBytes

public static org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.TableLock fromBytes(byte[] bytes)

Public for hbck