[Gluster-users] Giving up [ was: Re: read-subvolume]

[Jeff Darcy]

On 07/10/2013 09:20 AM, Allan Latham wrote:
> Where do I get a version that will solve my 'read local if we have the
> file here' problem.

I would say 3.4 is already far better than 3.3 not only in terms of features 
but stability/maintainability/etc. as well, even though it's technically not 
out of beta yet.  You can get it here:

http://download.gluster.org/pub/gluster/glusterfs/3.4/3.4.0beta4/

Selection of the local subvolume (if there is one) should happen automatically, 
and multiple users have reported that this is in fact the case.  You can also 
use the read-subvolume-index option to gain explicit control over this decision 
at mount time (via the --xlator-option hook).

> My use case is exactly two servers at a server farm with 100Mbit between
> them. This 100Mbit is also shared with the outside internet. Hence the
> need to minimise use of this very limited resource.

That's very similar to the use case for the person who submitted the 
read-subvolume-index patch.

> We are still in evaluation. Current 'best' is what we are familiar with
> = unison and inotify. I don't like it because it's really only a hack.
> However it works. If inotify misses a change due to race conditions
> unison gets run every five minutes anyway.

If you're running with that level of eventual consistency already, might 
geo-replication be a better fit for your needs?  It's a separate feature from 
normal (synchronous) replication, described in section 8 of the 3.3 admin guide.

http://www.gluster.org/wp-content/uploads/2012/05/Gluster_File_System-3.3.0-Administration_Guide-en-US.pdf

Unfortunately, I can't find the 3.4 admin guide on the Gluster site (another 
pet peeve) or I'd provide a link to that.