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From Aaron Morton <aa...@thelastpickle.com>
Subject Re: Storing log structured data in Cassandra without compactions for performance boost.
Date Wed, 14 May 2014 22:30:27 GMT
If you disable compaction you will end up with a *lot* of sstables, this will hurt read performance
and be a pain to manage (including making repairs and bootstrapping taking longer)

STCS is not too onerous, I’d recommend leaving on. If you want it to run less frequently
increase min_threshold. 

Cheers
Aaron

-----------------
Aaron Morton
New Zealand
@aaronmorton

Co-Founder & Principal Consultant
Apache Cassandra Consulting
http://www.thelastpickle.com

On 8/05/2014, at 8:36 am, DuyHai Doan <doanduyhai@gmail.com> wrote:

> Hello Kevin
> 
>  You can disable compaction by configuring the compaction options of your table as follow:
> 
>   compaction={'min_threshold': '0', 'class': 'SizeTieredCompactionStrategy', 'max_threshold':
'0'}
> 
> Regards
> 
>  Duy Hai DOAN
> 
> 
> On Wed, May 7, 2014 at 2:55 AM, Kevin Burton <burton@spinn3r.com> wrote:
> I'm looking at storing log data in Cassandra… 
> 
> Every record is a unique timestamp for the key, and then the log line for the value.
> 
> I think it would be best to just disable compactions.
> 
> - there will never be any deletes.
> 
> - all the data will be accessed in time range (probably partitioned randomly) and sequentially.
> 
> So every time a memtable flushes, we will just keep that SSTable forever.  
> 
> Compacting the data is kind of redundant in this situation.
> 
> I was thinking the best strategy is to use setcompactionthreshold and set the value VERY
high to compactions are never triggered.
> 
> Also, It would be IDEAL to be able to tell cassandra to just drop a full SSTable so that
I can truncate older data without having to do a major compaction and without having to mark
everything with a tombstone.  Is this possible?
> 
> 
> 
> -- 
> 
> Founder/CEO Spinn3r.com
> Location: San Francisco, CA
> Skype: burtonator
> blog: http://burtonator.wordpress.com
> … or check out my Google+ profile
> 
> War is peace. Freedom is slavery. Ignorance is strength. Corporations are people.
> 
> 


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