RegionGroupingProvider (Apache HBase 1.2.12 API)

java.lang.Object
- org.apache.hadoop.hbase.wal.RegionGroupingProvider

All Implemented Interfaces:

WALProvider

Direct Known Subclasses:

BoundedRegionGroupingProvider
```
@InterfaceAudience.Private
 class RegionGroupingProvider
extends Object
implements WALProvider
```
A WAL Provider that returns a WAL per group of regions. Region grouping is handled via RegionGroupingProvider.RegionGroupingStrategy and can be configured via the property "hbase.wal.regiongrouping.strategy". Current strategy choices are
- defaultStrategy : Whatever strategy this version of HBase picks. currently "identity".
- identity : each region belongs to its own group.
Optionally, a FQCN to a custom implementation may be given. WAL creation is delegated to another WALProvider, configured via the property "hbase.wal.regiongrouping.delegate". The property takes the same options as "hbase.wal.provider" (ref WALFactory) and defaults to the defaultProvider.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`(package private) static class`	`RegionGroupingProvider.IdentityGroupingStrategy`
`static interface`	`RegionGroupingProvider.RegionGroupingStrategy` Map identifiers to a group number.
`(package private) static class`	`RegionGroupingProvider.Strategies` Maps between configuration names for strategies and implementation classes.

Nested classes/interfaces inherited from interface org.apache.hadoop.hbase.wal.WALProvider
WALProvider.Writer

Field Summary

Fields
Modifier and Type	Field and Description
`protected ConcurrentMap<byte[],WALProvider>`	`cached`
`(package private) static String`	`DEFAULT_DELEGATE_PROVIDER`
`private static String`	`DEFAULT_REGION_GROUPING_STRATEGY`
`(package private) static String`	`DELEGATE_PROVIDER`
`private WALFactory`	`factory`
`private List<WALActionsListener>`	`listeners`
`private static org.apache.commons.logging.Log`	`LOG`
`private String`	`providerId`
`private static String`	`REGION_GROUPING_STRATEGY`
`protected RegionGroupingProvider.RegionGroupingStrategy`	`strategy`

Constructor Summary

Constructors
Constructor and Description

RegionGroupingProvider()

Constructors
Constructor and Description
`RegionGroupingProvider()`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`close()` shutdown utstanding WALs and clean up any persisted state.
`(package private) RegionGroupingProvider.RegionGroupingStrategy`	`getStrategy(org.apache.hadoop.conf.Configuration conf, String key, String defaultValue)` instantiate a strategy from a config property.
`WAL`	`getWAL(byte[] identifier)`
`void`	`init(WALFactory factory, org.apache.hadoop.conf.Configuration conf, List<WALActionsListener> listeners, String providerId)` Set up the provider to create wals.
`(package private) WALProvider`	`populateCache(byte[] group)` Populate the cache for this group.
`void`	`shutdown()` persist outstanding WALs to storage and stop accepting new appends.

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
```
  - REGION_GROUPING_STRATEGY
```
private static final String REGION_GROUPING_STRATEGY
```
    See Also:
    Constant Field Values
  - DEFAULT_REGION_GROUPING_STRATEGY
```
private static final String DEFAULT_REGION_GROUPING_STRATEGY
```
  - DELEGATE_PROVIDER
```
static final String DELEGATE_PROVIDER
```
    See Also:
    Constant Field Values
  - DEFAULT_DELEGATE_PROVIDER
```
static final String DEFAULT_DELEGATE_PROVIDER
```
  - cached
```
protected final ConcurrentMap<byte[],WALProvider> cached
```
  - strategy
```
protected RegionGroupingProvider.RegionGroupingStrategy strategy
```
  - factory
```
private WALFactory factory
```
  - listeners
```
private List<WALActionsListener> listeners
```
  - providerId
```
private String providerId
```
- Constructor Detail
  - RegionGroupingProvider
```
RegionGroupingProvider()
```
- Method Detail
  - getStrategy
```
RegionGroupingProvider.RegionGroupingStrategy getStrategy(org.apache.hadoop.conf.Configuration conf,
                                                        String key,
                                                        String defaultValue)
                                                    throws IOException
```
    instantiate a strategy from a config property. requires conf to have already been set (as well as anything the provider might need to read).
    
    Throws:
    
    IOException
  - init
```
public void init(WALFactory factory,
        org.apache.hadoop.conf.Configuration conf,
        List<WALActionsListener> listeners,
        String providerId)
          throws IOException
```
    Description copied from interface: WALProvider
    
    Set up the provider to create wals. will only be called once per instance.
    
    Specified by:
    
    init in interface WALProvider
    
    Parameters:
    factory - factory that made us may not be null
    conf - may not be null
    listeners - may be null
    providerId - differentiate between providers from one factory. may be null
    
    Throws:
    
    IOException
  - populateCache
```
WALProvider populateCache(byte[] group)
                    throws IOException
```
    Populate the cache for this group.
    
    Throws:
    
    IOException
  - getWAL
```
public WAL getWAL(byte[] identifier)
           throws IOException
```
    Specified by:
    
    getWAL in interface WALProvider
    
    Parameters:
    identifier - may not be null. contents will not be altered.
    
    Returns:
    a WAL for writing entries for the given region.
    
    Throws:
    
    IOException
  - shutdown
```
public void shutdown()
              throws IOException
```
    Description copied from interface: WALProvider
    
    persist outstanding WALs to storage and stop accepting new appends. This method serves as shorthand for sending a sync to every WAL provided by a given implementation. Those WALs will also stop accepting new writes.
    
    Specified by:
    
    shutdown in interface WALProvider
    
    Throws:
    
    IOException
  - close
```
public void close()
           throws IOException
```
    Description copied from interface: WALProvider
    
    shutdown utstanding WALs and clean up any persisted state. Call this method only when you will not need to replay any of the edits to the WALs from this provider. After this call completes, the underlying resources should have been reclaimed.
    
    Specified by:
    
    close in interface WALProvider
    
    Throws:
    
    IOException

Class RegionGroupingProvider

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.hadoop.hbase.wal.WALProvider

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

LOG

REGION_GROUPING_STRATEGY

DEFAULT_REGION_GROUPING_STRATEGY

DELEGATE_PROVIDER

DEFAULT_DELEGATE_PROVIDER

cached

strategy

factory

listeners

providerId

Constructor Detail

RegionGroupingProvider

Method Detail

getStrategy

init

populateCache

getWAL

shutdown

close