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https://issues.apache.org/jira/browse/ACCUMULO-4078?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Matt Peterson updated ACCUMULO-4078:
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    Description: 
A few improvements to the VolumeChooser are desired for a use case that seems 
general enough to warrant an update to Accumulo.  

Use Case:
A new volume is added, with limited capacity, to be dedicated for a specific 
table.  All other tables or files should be excluded from this new volume.

Suggested Improvements:
1. Update the signature for VolumeManager.choose to take a 
VolumeChooserEnvironment instead of Optional<String>.  This will allow future 
parameters for volume selection without repeatedly changing the VolumeManager 
interface.

2. It's not currently possible to specify preferred volumes for the write-ahead 
logs

3. In several places including PreferredVolumeChooser, PerTableVolumeChooser 
and VolumeManagerImpl, the failsafe chooser is the RandomVolumeChooser which 
will include the instance volume that needs to be excluded.  It would be useful 
to have a configurable failsafe in this situation.

4. The volume chooser is called in FileUtils for temp directory creation but it 
could instead use the sticky dir to create the temp directory, not needing the 
volume chooser at all.

The above suggestions could become sub-tickets.  Note that the improvements 
listed have been implemented for my particular instance and I hope to submit 
them as a patch.

  was:
A few improvements to the VolumeChooser are desired for a particular use case 
that seems to be general enough that it warrants an updated to Accumulo.  
Perhaps these ideas should become sub-tickets.  Note that the improvements 
listed below have been implemented for my particular instance and I expect to 
submit them as a patch.

Use Case:
A new volume is added, with limited capacity, to be dedicated for a specific 
table.  All other tables or files should be excluded from this new volume.

Suggested Improvements:
1. Update the signature for VolumeManager.choose to take a 
VolumeChooserEnvironment instead of Optional<String>.  This will allow future 
parameters for volume selection without repeatedly changing the VolumeManager 
interface.

2. It's not currently possible to specify preferred volumes for the write-ahead 
logs

3. In several places including PreferredVolumeChooser, PerTableVolumeChooser 
and VolumeManagerImpl, the failsafe chooser is the RandomVolumeChooser which 
will include the instance volume that needs to be excluded.  It would be useful 
to have a configurable failsafe in this situation.

4. The volume chooser is called in FileUtils for temp directory creation but it 
could instead use the sticky dir to create the temp directory, not needing the 
volume chooser at all.


> Exclude special volumes
> -----------------------
>
>                 Key: ACCUMULO-4078
>                 URL: https://issues.apache.org/jira/browse/ACCUMULO-4078
>             Project: Accumulo
>          Issue Type: Improvement
>          Components: core
>    Affects Versions: 1.7.0
>            Reporter: Matt Peterson
>            Priority: Minor
>              Labels: newbie
>
> A few improvements to the VolumeChooser are desired for a use case that seems 
> general enough to warrant an update to Accumulo.  
> Use Case:
> A new volume is added, with limited capacity, to be dedicated for a specific 
> table.  All other tables or files should be excluded from this new volume.
> Suggested Improvements:
> 1. Update the signature for VolumeManager.choose to take a 
> VolumeChooserEnvironment instead of Optional<String>.  This will allow future 
> parameters for volume selection without repeatedly changing the VolumeManager 
> interface.
> 2. It's not currently possible to specify preferred volumes for the 
> write-ahead logs
> 3. In several places including PreferredVolumeChooser, PerTableVolumeChooser 
> and VolumeManagerImpl, the failsafe chooser is the RandomVolumeChooser which 
> will include the instance volume that needs to be excluded.  It would be 
> useful to have a configurable failsafe in this situation.
> 4. The volume chooser is called in FileUtils for temp directory creation but 
> it could instead use the sticky dir to create the temp directory, not needing 
> the volume chooser at all.
> The above suggestions could become sub-tickets.  Note that the improvements 
> listed have been implemented for my particular instance and I hope to submit 
> them as a patch.



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