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From Antony Blakey <antony.bla...@gmail.com>
Subject Re: couchdb transactions changes
Date Sun, 08 Feb 2009 02:37:42 GMT

On 08/02/2009, at 12:05 PM, Damien Katz wrote:

> But if the replication doesn't complete, like in the middle you lose  
> your connection, then the downstream db is in an inconsistent state  
> and will be until you regain the connection and complete the  
> replication.

Sure, that's OK. In my case there are potentially millions of  
'downstreams'.

> And its not just the downstream dbs that can't be used during active  
> or interrupted replication, it's the central db as well. If you want  
> to update it, you'll have to shut down access while waiting for any  
> in progress replications to complete, then perform the update then  
> reopen replication access.

I can't see why this needs to be the case. The fact that there are  
peers that have an incomplete replication doesn't stop the master  
taking updates - iff the updates to the master are multi-document ACID.

In my case, replication can occur from any peer that isn't itself  
replicating, and has completed a valid replication cycle.

The key thing being, even with multiple writers i.e. symmetric peers,  
that replication occurs between nodes that are themselves consistent  
e.g. conflicts are never replicated, they are only the result of  
replication, and the node is locked until a replication cycle  
completes (or is abandoned, which is a separate issue that I have to  
address).

Am I missing something?

Antony Blakey
--------------------------
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