[Gluster-users] AFR caching

[Keith Freedman]

At 05:15 AM 10/22/2008, Vikas Gorur wrote:
>2008/10/22 martin <mpeacock at mater.ie>:
> > I've seen the various FAQs on the website saying there isn't metadata or
> > caching going on but then I can't get my head around how AFR knows what to
> > do when a brick goes offline and subsequently returns.  There must be some
> > record of what changes were made. Is this on disk or in memory?
>
>AFR uses a database like journal to keep track of changes. When a node comes
>back up, there will be a record on other nodes to say *some* changes
>are pending on the node that was down. AFR then simply copies the entire file
>and/or creates files on the node that came back up.

it's important to note that it "copies the entire file"
so if you have VERY large files, then this will create a lot of 
bandwidth and can take some time :)

>Vikas Gorur
>--
>Engineer - Z Research
>http://gluster.org/
>
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