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From Filipe David Manana <fdman...@gmail.com>
Subject Re: _replicator DB
Date Thu, 20 May 2010 22:29:03 GMT
On Thu, May 20, 2010 at 4:17 PM, Filipe David Manana <fdmanana@gmail.com>wrote:

> One question Adam:
>
> On Wed, May 19, 2010 at 8:35 PM, Adam Kocoloski <kocolosk@apache.org>wrote:
>
>>
>> > 3) Is the checkpoint ID generation algorithm backwards-compatible?  Or
>> will users who upgrade restart all replications from scratch?
>> >
>>
>
> To make it backward compatible, it means that independenly of replication
> document IDs, the _local documents would be the the same as before - that
> md5 of term_to_binary over a term composed of replication properties
> (source, target, continuous, etc).
>
> This way 2 replications document that differ only on their ID, would share
> the same replication log _local docs. If both are updating them, we have
> racing conditions, so one of the replication gen_servers will fail.
>

Forget this comment. The replicator is catching doc update conflict
exceptions therefore replicator gen_servers do not crash upon an update
conflict.
I think for now it can be safely ignored.

If this turns out to be bad, I'll revert to a former solution I had - using
the md5 based replication IDs as the gen_server IDs (however it was causing
some issues and needed a bit more code).

cheers


>
> --
>  Filipe David Manana,
> fdmanana@gmail.com
>
> "Reasonable men adapt themselves to the world.
> Unreasonable men adapt the world to themselves.
> That's why all progress depends on unreasonable men."
>
>


-- 
Filipe David Manana,
fdmanana@gmail.com

"Reasonable men adapt themselves to the world.
Unreasonable men adapt the world to themselves.
That's why all progress depends on unreasonable men."

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