hints compaction

[Dane Miller <da...@optimalsocial.com>]

Hi,

Several of my nodes have been compacting system.hints for over 24
hours with no progress, causing high load on otherwise idle nodes.
I'm seeing 30-50 Data.db files in system/hints/

What are the proper compaction settings for the hints CF?  Mine are:
compaction={'min_threshold': '0', 'class':
'SizeTieredCompactionStrategy', 'max_threshold': '0'}

Is hints compaction a common problem?  What are steps to remedy?

Thanks!

Dane

Re: hints compaction

[aaron morton <aa...@thelastpickle.com>]

> What are the proper compaction settings for the hints CF?  Mine are:
> compaction={'min_threshold': '0', 'class':
> 'SizeTieredCompactionStrategy', 'max_threshold': '0'}
Compaction is run manually by the code when it finishes delivering hints. 

> Is hints compaction a common problem?  What are steps to remedy?

Any errors in the logs ?
Are there many -tmp- files in the hint's dir ? 
Is your cluster having problems with flapping nodes or dropped messages that result in a lot of hint storage?

You could use nodetool to stop the compaction tasks then run a major compaction on the Hints CF. 

Cheers

-----------------
Aaron Morton
Freelance Cassandra Consultant
New Zealand

@aaronmorton
http://www.thelastpickle.com

On 2/04/2013, at 3:30 AM, Dane Miller <da...@optimalsocial.com> wrote:

> Hi,
> 
> Several of my nodes have been compacting system.hints for over 24
> hours with no progress, causing high load on otherwise idle nodes.
> I'm seeing 30-50 Data.db files in system/hints/
> 
> What are the proper compaction settings for the hints CF?  Mine are:
> compaction={'min_threshold': '0', 'class':
> 'SizeTieredCompactionStrategy', 'max_threshold': '0'}
> 
> Is hints compaction a common problem?  What are steps to remedy?
> 
> Thanks!
> 
> Dane