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Posted to user@cassandra.apache.org by Kanwar Sangha <ka...@mavenir.com> on 2013/06/20 21:17:30 UTC
block size
Hi - What is the block size for Cassandra ? is it taken from the OS defaults ?
Re: block size
Posted by aaron morton <aa...@thelastpickle.com>.
> If I have a data in column of size 500KB,
>
Also some information here http://thelastpickle.com/2011/04/28/Forces-of-Write-and-Read/
The data files are memory mapped so it's sort of OS dependant.
A
-----------------
Aaron Morton
Freelance Cassandra Consultant
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 21/06/2013, at 8:29 AM, Shahab Yunus <sh...@gmail.com> wrote:
> Ok. Though the closest that I can find is this (Aaron Morton's great blog):
> http://thelastpickle.com/2011/07/04/Cassandra-Query-Plans/
>
> I would also like to know the answer as, as such, I also haven't came across 'block size' as a core concept (or a concept to be considered while developing with) Cassandra unlike Hadoop.
>
> Regards,
> Shahab
>
>
> On Thu, Jun 20, 2013 at 3:38 PM, Kanwar Sangha <ka...@mavenir.com> wrote:
> Yes. Is that not specific to hadoop with CFS ? I want to know that If I have a data in column of size 500KB, how many IOPS are needed to read that ? (assuming we have key cache enabled)
>
>
>
>
>
> From: Shahab Yunus [mailto:shahab.yunus@gmail.com]
> Sent: 20 June 2013 14:32
> To: user@cassandra.apache.org
> Subject: Re: block size
>
>
>
> Have you seen this?
>
> http://www.datastax.com/dev/blog/cassandra-file-system-design
>
>
>
> Regards,
> Shahab
>
>
>
> On Thu, Jun 20, 2013 at 3:17 PM, Kanwar Sangha <ka...@mavenir.com> wrote:
>
> Hi – What is the block size for Cassandra ? is it taken from the OS defaults ?
>
>
>
>
Re: block size
Posted by Shahab Yunus <sh...@gmail.com>.
Ok. Though the closest that I can find is this (Aaron Morton's great blog):
http://thelastpickle.com/2011/07/04/Cassandra-Query-Plans/
I would also like to know the answer as, as such, I also haven't came
across 'block size' as a core concept (or a concept to be considered while
developing with) Cassandra unlike Hadoop.
Regards,
Shahab
On Thu, Jun 20, 2013 at 3:38 PM, Kanwar Sangha <ka...@mavenir.com> wrote:
> Yes. Is that not specific to hadoop with CFS ? I want to know that If I
> have a data in column of size 500KB, how many IOPS are needed to read that
> ? (assuming we have key cache enabled)****
>
> ** **
>
> ** **
>
> *From:* Shahab Yunus [mailto:shahab.yunus@gmail.com]
> *Sent:* 20 June 2013 14:32
> *To:* user@cassandra.apache.org
> *Subject:* Re: block size****
>
> ** **
>
> Have you seen this?****
>
> http://www.datastax.com/dev/blog/cassandra-file-system-design****
>
> ** **
>
> Regards,
> Shahab****
>
> ** **
>
> On Thu, Jun 20, 2013 at 3:17 PM, Kanwar Sangha <ka...@mavenir.com> wrote:
> ****
>
> Hi – What is the block size for Cassandra ? is it taken from the OS
> defaults ?****
>
> ** **
>
RE: block size
Posted by Kanwar Sangha <ka...@mavenir.com>.
Yes. Is that not specific to hadoop with CFS ? I want to know that If I have a data in column of size 500KB, how many IOPS are needed to read that ? (assuming we have key cache enabled)
From: Shahab Yunus [mailto:shahab.yunus@gmail.com]
Sent: 20 June 2013 14:32
To: user@cassandra.apache.org
Subject: Re: block size
Have you seen this?
http://www.datastax.com/dev/blog/cassandra-file-system-design
Regards,
Shahab
On Thu, Jun 20, 2013 at 3:17 PM, Kanwar Sangha <ka...@mavenir.com>> wrote:
Hi - What is the block size for Cassandra ? is it taken from the OS defaults ?
Re: block size
Posted by Shahab Yunus <sh...@gmail.com>.
Have you seen this?
http://www.datastax.com/dev/blog/cassandra-file-system-design
Regards,
Shahab
On Thu, Jun 20, 2013 at 3:17 PM, Kanwar Sangha <ka...@mavenir.com> wrote:
> Hi – What is the block size for Cassandra ? is it taken from the OS
> defaults ?****
>