[Gluster-users] Fwd: Glusterfs over wan?

[shayn at shayn.ch]

Thanks for explain..

So, you think, that with glusterfs, we can't have a replication between
two (or more) different site over the wan, when both site are active
(read and write functions) ?

On 27 mai 10 20:07 "Tejas N. Bhise" <tejas at gluster.com> wrote:

> Patricio,
> 
> All networked filesystems like nfs, cifs/samba and even GlusterFS can
> be used over WAN. The problem arises for the more complex
> functionality, like replication across a WAN.
> 
> Replication over WAN has different meanings for different users - some
> just want a good way to have a remote backup, others want a hot-cold
> kind of a backup so namespace issue come into the picture, but its
> relatively easier to solve as there is only one side active at a time.
> 
> The most difficult one is to keep both sites active ( and R/W ) with
> their own full namespace and security functionality with a designated
> unit of the filesystem replicated. Access from each side looks like it
> just pulled data from its own data cache and the currency of data
> could move around ( potentially ) multiple locations across the globe.
> 
> I don't think anyone does that last kind of replication. AFS and DFS
> from the old days did go upto a certain point by providing R/O
> replication with remote snapshots by providing integrated multisite
> security and namespace, but no R/W replication.
> 
> GlusterFS plan is to start with async WAN replication for remote
> backup and slowly moving into the multisite cluster architecture and
> active active replicated data copies with integrated namespace, which
> we hope to bring in with a new unified ( write ) caching.
> 
> Async WAN replication for remote backup might come in as early as end
> of the year with the other functionality following sometime after
> that.
> 
> I would like to hear more about how community users will put these
> different levels of WAN replication to use, how much data would change
> on a daily basis and hence get moved around, what kind of latency
> would be acceptable to your applications ? I would also like to hear
> if anyone is using other solutions/edge caching appliances etc to do
> this in other ways.
> 
> Regards,
> Tejas.
> 
> ----- Original Message -----
> From: "Patricio A. Bruna" <pbruna at it-linux.cl>
> To: <gluster-users at gluster.org>
> Sent: Thursday, May 27, 2010 10:00:12 PM
> Subject: Re: [Gluster-users] Fwd: Glusterfs over wan?
> 
> Hi,
> just for information, what file system are available to use over WAN?
> 
> 
> ------------------------------------ 
> Patricio Bruna V.
> IT Linux Ltda.
> <http://www.it-linux.cl>
> Fono : (+56-2) 333 0578
> Móvil: (+56-9) 7776 2899
> 
> 
> 
> 
> 
> 
> 
> 
> Hi Shayn,
> 
> The problem is not replication speed. Actually that part is just fine,
> and it's quite fast.
> 
> The problem with WAN is that when the gluster client receives a
> request to read the file, it first checks with all the nodes in the
> cluster, to make sure there are no discrepancies. Only after all nodes
> have answered, it will read the local file (if it's replicated
> locally).
> 
> Also take into account that international links are not as reliable as
> local LAN based links. If a node is suddenly inaccessible, it can slow
> down everything (again because READ operations are dependent on all
> nodes in the cluster answering, synchronously).
> 
> I know that the gluster team are working on an async solution, down
> the road, which would make glusterfs more suitable for WAN scenarios.
> 
> My suggestion is NOT to try it, until the gluster team officially
> announce WAN support.
> 
> 
> 
> On May 27, 2010, at 4:31 PM, <shayn at shayn.ch> wrote:
> 
> > 
> > Hello !
> > 
> > sorry for english, but, just don't understand why glusterfs is not
> > destinated to be used over the wan ?
> > I think that if the files are tiny, there's no problem to use this
> > solution over wan.. ?
> > 
> > But okay, if file are large.. (don't know .. 100MB - 200MB and
> > more.) i
> > understand that it depend of the internet connection and that's the
> > replication can be so soo soo slow..
> > 
> > Please, give me some renseignments about this solution over wan
> > 
> > Shayn_______________________________________________
> > Gluster-users mailing list
> > <Gluster-users at gluster.org>
> > <http://gluster.org/cgi-bin/mailman/listinfo/gluster-users>
> 
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