RandomVolumeChooser (Apache Accumulo Core 2.1.1 API)

java.lang.Object
- org.apache.accumulo.core.spi.fs.RandomVolumeChooser

All Implemented Interfaces:

VolumeChooser

Direct Known Subclasses:

PreferredVolumeChooser
```
public class RandomVolumeChooser
extends Object
implements VolumeChooser
```
A VolumeChooser that selects a volume at random from the list of provided volumes.

Since:

2.1.0

Constructor Summary

Constructors
Constructor Description

RandomVolumeChooser()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Set<String>`	`choosable(VolumeChooserEnvironment env, Set<String> options)`	Return the subset of all possible volumes that could be chosen across all invocations of `VolumeChooser.choose(VolumeChooserEnvironment, Set)`. This is currently used to determine if the chosen volumes can support the required filesystem operations for write ahead logs. There may be other use cases in the future.
`String`	`choose(VolumeChooserEnvironment env, Set<String> options)`	Selects a volume at random from the provided set of volumes.

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

- Constructor Detail
  - RandomVolumeChooser
```
public RandomVolumeChooser()
```
- Method Detail
  - choose
```
public String choose(VolumeChooserEnvironment env,
                     Set<String> options)
```
    Selects a volume at random from the provided set of volumes. The environment scope is not utilized.
    
    Specified by:
    
    choose in interface VolumeChooser
    
    Parameters:
    
    env - the server environment provided by the calling framework
    
    options - the list of volumes to choose from
    
    Returns:
    
    a volume from the list of volume options
  - choosable
```
public Set<String> choosable(VolumeChooserEnvironment env,
                             Set<String> options)
```
    Description copied from interface: VolumeChooser
    
    Return the subset of all possible volumes that could be chosen across all invocations of VolumeChooser.choose(VolumeChooserEnvironment, Set).
    This is currently used to determine if the chosen volumes can support the required filesystem operations for write ahead logs.
    There may be other use cases in the future.
    
    Specified by:
    
    choosable in interface VolumeChooser
    
    Returns:
    
    same set of volume options that were originally provided.