Thanks that clears up a lot about what is going on. I am not familiar with
xattr. I tried getfattr -d <somefile> on both the brick, and glusterfs
client, and nothing showed up.
Does this information also exist in for directories?
Also, I see the algorithm checks for latest createtime. I think something is
missing. I would think that lastmodified time needs to also be kept track
of to know which brick has the latest version. For Example, if I have Brick1
and Brick2, and they both exist when a file is created, then B2 goes down.
Let's say that <somefile> got modified in the interim while B2 was down.
When B2 comes back up, both files will have the same file create time, but
B1 will have a newer file modified time. I assume under the current
algorithm, both files on B1 and B2 would be considered as the same file by
glusterfs. Oh. my bad, I see now that you are using the trusted.afr.version
to keep track of which is modified later. I see some of the tradeoffs
between lastmodified time vs version. Are these times relative to the server
clock or client clock?
I recall with DFS, that the clock or time management was a huge part of the
design. I'm using a bunch of test boxes right now (in a production
environment, this might be less of a problem with well managed boxes), but
sometimes the boxes are off a little on the clocks as until I remember to
run NTP. Is there a big impact to glusterfs re-syncing if the clocks are
off?
From: "Krishna Srinivas" <krishna@xxxxxxxxxxxxx>
To: "DeeDee Park" <deedee6905@xxxxxxxxxxx>
CC: gluster-devel@xxxxxxxxxx
Subject: Re: AFR bricks - how does it resync question
Date: Tue, 31 Jul 2007 21:02:05 +0530
DeeDee,
http://lists.gnu.org/archive/html/gluster-devel/2007-07/msg00008.html
See if that helps.
Regards
Krishna
On 7/31/07, DeeDee Park <deedee6905@xxxxxxxxxxx> wrote:
> If I have two bricks B1, and B2, and they are replicas using AFR.
> If one of the bricks goes down and has an older copy of a file, and then
> comes backup,
> if a file is being appended, how does the AFR know which copy to update?
>
> _________________________________________________________________
> http://newlivehotmail.com
>
>
>
> _______________________________________________
> Gluster-devel mailing list
> Gluster-devel@xxxxxxxxxx
> http://lists.nongnu.org/mailman/listinfo/gluster-devel
>
_________________________________________________________________
Don't get caught with egg on your face. Play Chicktionary!
http://club.live.com/chicktionary.aspx?icid=chick_hotmailtextlink2
