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From aaron morton <aa...@thelastpickle.com>
Subject Re: SSTable Num
Date Fri, 22 Feb 2013 16:40:07 GMT
> Ok. So for 10 TB, I could have at least 4 SStables files each of 2.5 TB ?
You will have many sstables, in your case 32. 
Each bucket of files (files that are within 50% of the average size of files in a bucket)
will contain 3 or less files. 

This article provides com back ground, but it's working correctly as you have described it

http://www.datastax.com/dev/blog/when-to-use-leveled-compaction

Cheers

-----------------
Aaron Morton
Freelance Cassandra Developer
New Zealand

@aaronmorton
http://www.thelastpickle.com

On 22/02/2013, at 6:39 AM, Kanwar Sangha <kanwar@mavenir.com> wrote:

> No. 
> The default size tiered strategy compacts files what are roughly the same size, and only
when there are more than 4 (default) of them.
>  
> Ok. So for 10 TB, I could have at least 4 SStables files each of 2.5 TB ?
>  
> From: aaron morton [mailto:aaron@thelastpickle.com] 
> Sent: 21 February 2013 11:01
> To: user@cassandra.apache.org
> Subject: Re: SSTable Num
>  
> Hi – I have around 6TB of data on 1 node
> Unless you have SSD and 10GbE you probably have too much data on there. 
> Remember you need to run repair and that can take a long time with a lot of data. Also
you may need to replace a node one day and moving 6TB will take a while.
>  
>  Or will the sstable compaction continue and eventually we will have 1 file ?
> No. 
> The default size tiered strategy compacts files what are roughly the same size, and only
when there are more than 4 (default) of them.
>  
> Cheers
>   
> -----------------
> Aaron Morton
> Freelance Cassandra Developer
> New Zealand
>  
> @aaronmorton
> http://www.thelastpickle.com
>  
> On 21/02/2013, at 3:47 AM, Kanwar Sangha <kanwar@mavenir.com> wrote:
> 
> 
> Hi – I have around 6TB of data on 1 node and the cfstats show 32 sstables. There is
no compaction job running in the background. Is there a limit on the size per sstable ? Or
will the sstable compaction continue and eventually we will have 1 file ?
>  
> Thanks,
> Kanwar
>  


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