Hi, the 'createtime' is only used to detect 'recrection' of files. if an existing file is edited, the syncing logic maintains its own cvs-like file versioning in the extended attributes and does not rely upon mtime. we felt that dependency on mtime is risky, a pain to setup (synchronizing system clock etc), and also the granularity of mtime is limited. thanks, avati 2007/8/1, DeeDee Park <deedee6905@xxxxxxxxxxx>: > > 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 > > > > _______________________________________________ > Gluster-devel mailing list > Gluster-devel@xxxxxxxxxx > http://lists.nongnu.org/mailman/listinfo/gluster-devel > -- Anand V. Avati
