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From "R. Verlangen" <ro...@us2.nl>
Subject Re: keycache persisted to disk ?
Date Mon, 13 Feb 2012 08:04:40 GMT
This is because of the "warm up" of Cassandra as it starts. On a start it
will start fetching the rows that were cached: this will have to be loaded
from the disk, as there is nothing in the cache yet. You can read more
about this at  http://wiki.apache.org/cassandra/LargeDataSetConsiderations

2012/2/13 Franc Carter <franc.carter@sirca.org.au>

> On Mon, Feb 13, 2012 at 5:03 PM, zhangcheng <zhangcheng@jike.com> wrote:
>
>> **
>>
>> I think the keycaches and rowcahches are bothe persisted to disk when
>> shutdown, and restored from disk when restart, then improve the performance.
>>
>
> Thanks - that would explain at least some of what I am seeing
>
> cheers
>
>
>>
>> 2012-02-13
>> ------------------------------
>>  zhangcheng
>> ------------------------------
>> *发件人:* Franc Carter
>> *发送时间:* 2012-02-13  13:53:56
>> *收件人:* user
>> *抄送:*
>> *主题:* keycache persisted to disk ?
>>
>> Hi,
>>
>> I am testing Cassandra on Amazon and finding performance can vary fairly
>> wildly. I'm leaning towards it being an artifact of the AWS I/O system but
>> have one other possibility.
>>
>> Are keycaches persisted to disk and restored on a clean shutdown and
>> restart ?
>>
>> cheers
>>
>> --
>>
>> *Franc Carter* | Systems architect | Sirca Ltd
>> <marc.zianideferranti@sirca.org.au>
>>
>> franc.carter@sirca.org.au | www.sirca.org.au
>>
>> Tel: +61 2 9236 9118
>>
>> Level 9, 80 Clarence St, Sydney NSW 2000
>>
>> PO Box H58, Australia Square, Sydney NSW 1215
>>
>>
>
>
> --
>
> *Franc Carter* | Systems architect | Sirca Ltd
>  <marc.zianideferranti@sirca.org.au>
>
> franc.carter@sirca.org.au | www.sirca.org.au
>
> Tel: +61 2 9236 9118
>
> Level 9, 80 Clarence St, Sydney NSW 2000
>
> PO Box H58, Australia Square, Sydney NSW 1215
>
>

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