NamespaceAuditor (Apache HBase 1.4.11 API)

java.lang.Object
- org.apache.hadoop.hbase.namespace.NamespaceAuditor

```
@InterfaceAudience.Private
public class NamespaceAuditor
extends Object
```
The Class NamespaceAuditor performs checks to ensure operations like table creation and region splitting preserve namespace quota. The namespace quota can be specified while namespace creation.

Constructor Summary

Constructors
Constructor and Description

NamespaceAuditor(MasterServices masterServices)

Constructors
Constructor and Description
`NamespaceAuditor(MasterServices masterServices)`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addNamespace(NamespaceDescriptor ns)`
`void`	`checkQuotaToCreateTable(TableName tName, int regions)` Check quota to create table.
`void`	`checkQuotaToSplitRegion(HRegionInfo hri)`
`void`	`checkQuotaToUpdateRegion(TableName tName, int regions)` Check and update region count quota for an existing table.
`void`	`deleteNamespace(String namespace)`
`int`	`getRegionCountOfTable(TableName tName)` Get region count for table
`org.apache.hadoop.hbase.namespace.NamespaceTableAndRegionInfo`	`getState(String namespace)`
`boolean`	`isInitialized()` Checks if namespace auditor is initialized.
`void`	`removeFromNamespaceUsage(TableName tableName)`
`void`	`removeRegionFromNamespaceUsage(HRegionInfo hri)`
`void`	`start()`
`void`	`updateQuotaForRegionMerge(HRegionInfo hri)`

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

- Constructor Detail
  - NamespaceAuditor
```
public NamespaceAuditor(MasterServices masterServices)
```
- Method Detail
  - start
```
public void start()
           throws IOException
```
    Throws:
    
    IOException
  - checkQuotaToCreateTable
```
public void checkQuotaToCreateTable(TableName tName,
                           int regions)
                             throws IOException
```
    Check quota to create table. We add the table information to namespace state cache, assuming the operation will pass. If the operation fails, then the next time namespace state chore runs namespace state cache will be corrected.
    
    Parameters:
    tName - - The table name to check quota.
    regions - - Number of regions that will be added.
    
    Throws:
    
    IOException - Signals that an I/O exception has occurred.
  - checkQuotaToUpdateRegion
```
public void checkQuotaToUpdateRegion(TableName tName,
                            int regions)
                              throws IOException
```
    Check and update region count quota for an existing table.
    
    Parameters:
    tName - - table name for which region count to be updated.
    regions - - Number of regions that will be added.
    
    Throws:
    
    IOException - Signals that an I/O exception has occurred.
  - getRegionCountOfTable
```
public int getRegionCountOfTable(TableName tName)
                          throws IOException
```
    Get region count for table
    
    Parameters:
    tName - - table name
    
    Returns:
    cached region count, or -1 if table status not found
    
    Throws:
    
    IOException - Signals that the namespace auditor has not been initialized
  - checkQuotaToSplitRegion
```
public void checkQuotaToSplitRegion(HRegionInfo hri)
                             throws IOException
```
    Throws:
    
    IOException
  - updateQuotaForRegionMerge
```
public void updateQuotaForRegionMerge(HRegionInfo hri)
                               throws IOException
```
    Throws:
    
    IOException
  - addNamespace
```
public void addNamespace(NamespaceDescriptor ns)
                  throws IOException
```
    Throws:
    
    IOException
  - deleteNamespace
```
public void deleteNamespace(String namespace)
                     throws IOException
```
    Throws:
    
    IOException
  - removeFromNamespaceUsage
```
public void removeFromNamespaceUsage(TableName tableName)
                              throws IOException
```
    Throws:
    
    IOException
  - removeRegionFromNamespaceUsage
```
public void removeRegionFromNamespaceUsage(HRegionInfo hri)
                                    throws IOException
```
    Throws:
    
    IOException
  - getState
```
public org.apache.hadoop.hbase.namespace.NamespaceTableAndRegionInfo getState(String namespace)
```
    Parameters:
    namespace - The name of the namespace
    
    Returns:
    An instance of NamespaceTableAndRegionInfo
  - isInitialized
```
public boolean isInitialized()
```
    Checks if namespace auditor is initialized. Used only for testing.
    
    Returns:
    true, if is initialized

Class NamespaceAuditor

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

NamespaceAuditor

Method Detail

start

checkQuotaToCreateTable

checkQuotaToUpdateRegion

getRegionCountOfTable

checkQuotaToSplitRegion

updateQuotaForRegionMerge

addNamespace

deleteNamespace

removeFromNamespaceUsage

removeRegionFromNamespaceUsage

getState

isInitialized