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From Ian Boston <...@tfd.co.uk>
Subject Re: Behaviour of Move Operations
Date Mon, 04 Mar 2013 10:08:25 GMT
On 4 March 2013 21:00, Thomas Mueller <mueller@adobe.com> wrote:
> Hi,
>
>>Are there any plans (or has someone already done) a CassandraMK
>
> I'm not aware of plans to write a CassandraMK. Currently we concentrate on
> MongoDB. Possibly Cassandra could be supported quite easily by
> implementing the org.apache.jackrabbit.mongomk.prototype.DocumentStore
> interface, but I didn't look into that.

thanks for the pointer.

>
>>is
>>there something in the Oak design that would prevent that level of
>>eventual consistency ? (I guess that might trading consistency for
>>scalability)
>
> ... or consistency for performance.

true.

>
> I didn't test it, but I guess eventual consistency would work within Oak.
> I would actually be more worried about how *users* (and developers) can
> deal with inconsistencies. It might be confusing for a user if he can
> successfully save changes, but then his changes are lost or garbled
> because somebody else changed the same item at the same time. If we do
> allow inconsistencies within the MicroKernel, I guess it would help if
> this could be configured on a path level (/libs is always consistent,
> /comments is eventually consistent or so).

I think (but dont know for certain) that that would require the paths
being store in different column families. Is it possible to
differentiate between subtrees at the DocumentStore interface level or
are the objects too abstract by then ?

I can bet the order in which values become eventually consistent is
non-deterministic.

Ian

>
> Regards,
> Thomas
>

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