CatalogJanitor (Apache HBase 1.2.12 API)

java.lang.Object
- org.apache.hadoop.hbase.ScheduledChore
- - org.apache.hadoop.hbase.master.CatalogJanitor

All Implemented Interfaces:

Runnable
```
@InterfaceAudience.Private
public class CatalogJanitor
extends ScheduledChore
```
A janitor for the catalog tables. Scans the hbase:meta catalog table on a period looking for unused regions to garbage collect.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`(package private) static class`	`CatalogJanitor.SplitParentFirstComparator` Compare HRegionInfos in a way that has split parents sort BEFORE their daughters.

Field Summary

Fields
Modifier and Type	Field and Description
`private AtomicBoolean`	`alreadyRunning`
`private Connection`	`connection`
`private AtomicBoolean`	`enabled`
`private static org.apache.commons.logging.Log`	`LOG`
`private Server`	`server`
`private MasterServices`	`services`

Constructor Summary

Constructors
Constructor and Description

CatalogJanitor(Server server, MasterServices services)

Constructors
Constructor and Description
`CatalogJanitor(Server server, MasterServices services)`

Method Summary

Methods
Modifier and Type	Method and Description
`(package private) Pair<Boolean,Boolean>`	`checkDaughterInFs(HRegionInfo parent, HRegionInfo daughter)` Checks if a daughter region -- either splitA or splitB -- still holds references to parent.
`protected void`	`chore()` The task to execute on each scheduled execution of the Chore
`boolean`	`cleanMergeQualifier(HRegionInfo region)` Checks if the specified region has merge qualifiers, if so, try to clean them
`(package private) boolean`	`cleanMergeRegion(HRegionInfo mergedRegion, HRegionInfo regionA, HRegionInfo regionB)` If merged region no longer holds reference to the merge regions, archive merge region on hdfs and perform deleting references in hbase:meta
`(package private) boolean`	`cleanParent(HRegionInfo parent, Result rowContent)` If daughters no longer hold reference to the parents, delete the parent.
`(package private) boolean`	`getEnabled()`
`(package private) Triple<Integer,Map<HRegionInfo,Result>,Map<HRegionInfo,Result>>`	`getMergedRegionsAndSplitParents()` Scans hbase:meta and returns a number of scanned rows, and a map of merged regions, and an ordered map of split parents.
`(package private) Triple<Integer,Map<HRegionInfo,Result>,Map<HRegionInfo,Result>>`	`getMergedRegionsAndSplitParents(TableName tableName)` Scans hbase:meta and returns a number of scanned rows, and a map of merged regions, and an ordered map of split parents.
`private HTableDescriptor`	`getTableDescriptor(TableName tableName)`
`private boolean`	`hasNoReferences(Pair<Boolean,Boolean> p)`
`protected boolean`	`initialChore()` Override to run a task before we start looping.
`(package private) int`	`scan()` Run janitorial scan of catalog `hbase:meta` table looking for garbage to collect.
`boolean`	`setEnabled(boolean enabled)`

Methods inherited from class org.apache.hadoop.hbase.ScheduledChore
cancel, cancel, choreForTesting, cleanup, getInitialDelay, getName, getPeriod, getStopper, getTimeUnit, isInitialChoreComplete, isScheduled, run, toString, triggerNow

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - LOG
```
private static final org.apache.commons.logging.Log LOG
```
  - server
```
private final Server server
```
  - services
```
private final MasterServices services
```
  - enabled
```
private AtomicBoolean enabled
```
  - alreadyRunning
```
private AtomicBoolean alreadyRunning
```
  - connection
```
private final Connection connection
```
- Constructor Detail
  - CatalogJanitor
```
CatalogJanitor(Server server,
              MasterServices services)
```
- Method Detail
  - initialChore
```
protected boolean initialChore()
```
    Description copied from class: ScheduledChore
    
    Override to run a task before we start looping.
    
    Overrides:
    
    initialChore in class ScheduledChore
    
    Returns:
    true if initial chore was successful
  - setEnabled
```
public boolean setEnabled(boolean enabled)
```
    Parameters:
    enabled -
  - getEnabled
```
boolean getEnabled()
```
  - chore
```
protected void chore()
```
    Description copied from class: ScheduledChore
    
    The task to execute on each scheduled execution of the Chore
    
    Specified by:
    
    chore in class ScheduledChore
  - getMergedRegionsAndSplitParents
```
Triple<Integer,Map<HRegionInfo,Result>,Map<HRegionInfo,Result>> getMergedRegionsAndSplitParents()
                                                                                          throws IOException
```
    Scans hbase:meta and returns a number of scanned rows, and a map of merged regions, and an ordered map of split parents.
    
    Returns:
    triple of scanned rows, map of merged regions and map of split parent regioninfos
    
    Throws:
    
    IOException
  - getMergedRegionsAndSplitParents
```
Triple<Integer,Map<HRegionInfo,Result>,Map<HRegionInfo,Result>> getMergedRegionsAndSplitParents(TableName tableName)
                                                                                          throws IOException
```
    Scans hbase:meta and returns a number of scanned rows, and a map of merged regions, and an ordered map of split parents. if the given table name is null, return merged regions and split parents of all tables, else only the specified table
    
    Parameters:
    tableName - null represents all tables
    
    Returns:
    triple of scanned rows, and map of merged regions, and map of split parent regioninfos
    
    Throws:
    
    IOException
  - cleanMergeRegion
```
boolean cleanMergeRegion(HRegionInfo mergedRegion,
                       HRegionInfo regionA,
                       HRegionInfo regionB)
                   throws IOException
```
    If merged region no longer holds reference to the merge regions, archive merge region on hdfs and perform deleting references in hbase:meta
    
    Parameters:
    mergedRegion -
    regionA -
    regionB -
    
    Returns:
    true if we delete references in merged region on hbase:meta and archive the files on the file system
    
    Throws:
    
    IOException
  - scan
```
int scan()
   throws IOException
```
    Run janitorial scan of catalog hbase:meta table looking for garbage to collect.
    
    Returns:
    number of cleaned regions
    
    Throws:
    
    IOException
  - cleanParent
```
boolean cleanParent(HRegionInfo parent,
                  Result rowContent)
              throws IOException
```
    If daughters no longer hold reference to the parents, delete the parent.
    
    Parameters:
    parent - HRegionInfo of split offlined parent
    rowContent - Content of parent row in metaRegionName
    
    Returns:
    True if we removed parent from meta table and from the filesystem.
    
    Throws:
    
    IOException
  - hasNoReferences
```
private boolean hasNoReferences(Pair<Boolean,Boolean> p)
```
    Parameters:
    p - A pair where the first boolean says whether or not the daughter region directory exists in the filesystem and then the second boolean says whether the daughter has references to the parent.
    
    Returns:
    True the passed p signifies no references.
  - checkDaughterInFs
```
Pair<Boolean,Boolean> checkDaughterInFs(HRegionInfo parent,
                                      HRegionInfo daughter)
                                  throws IOException
```
    Checks if a daughter region -- either splitA or splitB -- still holds references to parent.
    
    Parameters:
    parent - Parent region
    daughter - Daughter region
    
    Returns:
    A pair where the first boolean says whether or not the daughter region directory exists in the filesystem and then the second boolean says whether the daughter has references to the parent.
    
    Throws:
    
    IOException
  - getTableDescriptor
```
private HTableDescriptor getTableDescriptor(TableName tableName)
                                     throws FileNotFoundException,
                                            IOException
```
    Throws:
    
    FileNotFoundException
    
    IOException
  - cleanMergeQualifier
```
public boolean cleanMergeQualifier(HRegionInfo region)
                            throws IOException
```
    Checks if the specified region has merge qualifiers, if so, try to clean them
    
    Parameters:
    region -
    
    Returns:
    true if the specified region doesn't have merge qualifier now
    
    Throws:
    
    IOException

Class CatalogJanitor

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class org.apache.hadoop.hbase.ScheduledChore

Methods inherited from class java.lang.Object

Field Detail

LOG

server

services

enabled

alreadyRunning

connection

Constructor Detail

CatalogJanitor

Method Detail

initialChore

setEnabled

getEnabled

chore

getMergedRegionsAndSplitParents

getMergedRegionsAndSplitParents

cleanMergeRegion

scan

cleanParent

hasNoReferences

checkDaughterInFs

getTableDescriptor

cleanMergeQualifier