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From Adam Kocoloski <adam.kocolo...@gmail.com>
Subject Re: progress on streaming attachments during replication
Date Fri, 13 Feb 2009 00:32:11 GMT
On Feb 12, 2009, at 7:10 PM, Chris Anderson wrote:

> On Thu, Feb 12, 2009 at 4:01 PM, Adam Kocoloski
> <adam.kocoloski@gmail.com> wrote:
>> Hi devs, I spent a good bit of time over the last two days on  
>> attachment
>> replication.  I started with pull replication since I had a pretty  
>> clear
>> idea of what I wanted to do there:
>
> Sounds like you're on the right track. I'd suggest contacting
> Chandrashekhar directly.
>
> Tonight I hope to be checking in some code that allows chunked
> attachment PUT, for those times when you don't know how big an
> attachment is. Hopefully it won't effect what you are doing, but it
> does modify the pattern matching within doc_flush_binaries

Ok, thanks, I'll keep an eye out for that.  I doubt it'll be a problem.

> The only problem I can see with concurrent attachment streaming is if
> 2 attachments on the same doc are happening at the same time, you
> could have a race condition about the doc._rev.

Hmm, I don't think that'll be an issue with the pull case -- doc._rev  
is only updated once, regardless of the number of attachments.

It could be tricky if I tried to PUT multiple attachments from a  
single doc to a remote target concurrently; that's one of the reasons  
I did pull first.  Hopefully push can wait till multipart requests are  
available, then we can just stuff all the updates for a doc into one  
request.

Adam

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