TableLockManager (Apache HBase 1.2.12 API)

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

Direct Known Subclasses:

TableLockManager.NullTableLockManager, TableLockManager.ZKTableLockManager
```
@InterfaceAudience.Private
public abstract class TableLockManager
extends Object
```
A manager for distributed table level locks.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`TableLockManager.NullTableLockManager` A null implementation
`static interface`	`TableLockManager.TableLock` A distributed lock for a table.
`private static class`	`TableLockManager.ZKTableLockManager` ZooKeeper based TableLockManager

Field Summary

Fields
Modifier and Type	Field and Description
`private static boolean`	`DEFAULT_TABLE_LOCK_ENABLE` by default we should enable table-level locks for schema changes
`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`
`private static org.apache.commons.logging.Log`	`LOG`
`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

Constructors
Constructor and Description

TableLockManager()

Constructors
Constructor and Description
`TableLockManager()`

Method Summary

Methods
Modifier and Type	Method and Description
`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
  - LOG
```
private static final org.apache.commons.logging.Log LOG
```
  - 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
  - DEFAULT_TABLE_LOCK_ENABLE
```
private static final boolean DEFAULT_TABLE_LOCK_ENABLE
```
    by default we should enable 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

Class TableLockManager

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

LOG

TABLE_LOCK_ENABLE

DEFAULT_TABLE_LOCK_ENABLE

TABLE_WRITE_LOCK_TIMEOUT_MS

TABLE_READ_LOCK_TIMEOUT_MS

DEFAULT_TABLE_WRITE_LOCK_TIMEOUT_MS

DEFAULT_TABLE_READ_LOCK_TIMEOUT_MS

TABLE_LOCK_EXPIRE_TIMEOUT

DEFAULT_TABLE_LOCK_EXPIRE_TIMEOUT_MS

Constructor Detail

TableLockManager

Method Detail

writeLock

readLock

visitAllLocks

reapAllExpiredLocks

reapWriteLocks

tableDeleted

createTableLockManager

fromBytes