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From aaron morton <aa...@thelastpickle.com>
Subject Re: enforcing ordering
Date Thu, 10 May 2012 11:05:53 GMT
Kewl. 

I'd be interested to know what you come up with. 

Cheers

-----------------
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com

On 10/05/2012, at 3:03 PM, Franc Carter wrote:

> 
> 
> On Tue, May 8, 2012 at 8:21 PM, Franc Carter <franc.carter@sirca.org.au> wrote:
> On Tue, May 8, 2012 at 8:09 PM, aaron morton <aaron@thelastpickle.com> wrote:
> Can you store the corrections in a separate CF? 
> 
> We sat down and thought about this harder - it looks like a good solution for us that
may makel other hard problems go away - thanks.
>  
> cheers
> 
> 
> Yes, I thought of that, but that turns on read in to two ;-(
>  
> 
> When the client reads the key, reads from the original the corrects CF at the same time.
Apply the correction only on the client side. 
> 
> When you have confirmed the ingest has completed, run a background jobs to apply the
corrections, store the updated values and delete the correction data.
> 
> I was thinking down this path, but I ended up chasing the rabbit down a deep hole of
race conditions . . . 
> 
> cheers
>  
> 
> Cheers
> 
> -----------------
> Aaron Morton
> Freelance Developer
> @aaronmorton
> http://www.thelastpickle.com
> 
> On 8/05/2012, at 9:35 PM, Franc Carter wrote:
> 
>> 
>> Hi,
>> 
>> I'm wondering if there is a common 'pattern' to address a scenario we will have to
deal with.
>> 
>> We will be storing a set of Column/Value pairs per Key where the Column/Values are
read from a set of files that we download regularly. We need the loading to be resilient and
we can receive corrections for some of the Column/Values that can only be loaded after the
initial data has been inserted.
>> 
>> The challenge we have is that we have a strong preference for active/active loading
of data and can't see how to achieve this without some form of serialisation (which Cassandra
doesn't support - correct ?)
>> 
>> thanks
>> 
>> -- 
>> Franc Carter | Systems architect | Sirca Ltd
>> 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
> 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
> 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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