[Gluster-users] glusterfs performance issues

[Whit Blauvelt]

On Tue, Jan 08, 2013 at 01:11:24PM +0100, Stephan von Krawczynski wrote:

> Nobody besides you is talking about timestamps. I would simply choose an
> increasing stamp, increased by every write-touch of the file.
> In a trivial comparison this assures you choose the latest copy of the file.
> There is really no time needed at all, and therefore no time synchronisation
> issues.

So rather than the POSIX attribute of a time stamp, which is I'm pretty sure
what we all thought you were talking about, you're asking for a new
xattribute? And you want that to be simply iterative? Okay, so in a
split-brain, a file gets touched 5 times on one side, and actually written
to just once, not touched at all, on the other. Then the system's brought
back together. Your "trivial comparison" will choose the wrong file version.

That's the thing about complex systems. Trivial solutions are usually both
simple and wrong. Some work most of the time, but there are corner cases. As
we see with Gluster even complex solutions tend to have corner cases; but at
least in complex solutions the corners can be whittled down.

Regards,
Whit