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From DuyHai Doan <doanduy...@gmail.com>
Subject Re: Cassandra memory consumption
Date Thu, 10 Apr 2014 20:16:36 GMT
"what portion of the above is in the memtable ?"  --> partition key +
clustering key + stored data + memtable data structure size (actually it is
a ConcurrentSkipListMap so I guess there is some overhead with the data
structure)

If the data has been "flushed" to disk (data directory) the memtable is
again empty...


On Thu, Apr 10, 2014 at 10:10 PM, Parag Patel <ppatel@clearpoolgroup.com>wrote:

>  If I'm inserting the following :
>
>
>
> Partition key = 8 byte String
>
> Clustering key = 20 byte String
>
> Stored Data = 150 byte byte[]
>
>
>
> If the insert is still in the memtable, what portion of the above is in
> the memtable?  All of it, or just the keys?  If just the keys, where does
> the stored data live?  (keep in mind in this scenario the data has been
> been purged to the data directory.  It's only been added to the commit log).
>
>
>
> Parag
>
>
>
> *From:* DuyHai Doan [mailto:doanduyhai@gmail.com]
> *Sent:* Thursday, April 10, 2014 3:35 PM
> *To:* user@cassandra.apache.org
> *Subject:* Re: Cassandra memory consumption
>
>
>
> Data structures that are stored off heaps:
>
> 1) Row cache (if JNA enabled, otherwise on heap)
>
> 2) Bloom filter
>
> 3) Compression offset
>
> 4) Key Index sample
>
> On heap:
>
>  1) Memtables
>
>  2) Partition Key cache
>
> Hope that I did not forget anything
>
>  Regards
>
>  Duy Hai DOAN
>
>
>
> On Thu, Apr 10, 2014 at 9:13 PM, Parag Patel <ppatel@clearpoolgroup.com>
> wrote:
>
> We're using Cassandra 1.2.12.  What aspects of the data is stored in off
> heap memory vs heap memory?
>
>
>

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