[Gluster-users] Is mirroring provides failover protection?

[Sergiy Lozovsky]

Hi Andrew,

thanks for your response. I can use Gluster client. I would expect more straightforward approach for reliability. Gluster client could be configured during "mount" with IP addresses of all mirrors. I thought that I'm missing something, but it looks that it's not in the design at all :-(

The good news is that according to you Gluster client can switch between mirrors. That means it should be relatively easy to ad multiple IP configuration.

Thanks,

Sergiy.

--- On Wed, 1/19/11, Andrew Séguin <aseguo at gmail.com> wrote:

> From: Andrew Séguin <aseguo at gmail.com>
> Subject: Re: [Gluster-users] Is mirroring provides failover protection?
> To: "Sergiy Lozovsky" <serge_lozovsky at yahoo.com>
> Cc: gluster-users at gluster.org
> Date: Wednesday, January 19, 2011, 2:10 AM
> Hi,
> 
> Assuming the replication works fine (you see the files on
> both servers
> A and B) and that you use the Gluster client (mount -t
> glusterfs ...),
> then if server A goes down, your application will continue
> seamlessly
> to use server B although you could encounter problems
> later:
> 
> If the server with your application has to restart, and
> server A is
> down at that moment, then unfortunately the gluster client
> does not
> connect to a gluster server, and does not get to know that
> server B
> exists.
> 
> To avoid that problem, you can prepare your Gluster cluster
> system
> with 3 IP addresses: server A, server B, and a "shared" IP
> for the two
> nodes which will be active only on one of the two servers
> at a time.
> Some system then has to decide which server is currently
> master -- the
> CARP protocol could be of help here. Maybe the following
> blog/howto
> would be of help for this:
> http://www.misdivision.com/blog/setting-up-a-highly-available-storage-cluster-using-glusterfs-and-ucarp
> 
> With NFS & CIFS the clients don't know about the second
> server, in
> case you do not have a shared IP, the connection would be
> broken. NFS
> without the shared IP is the same as having an offline
> backup but with
> the advantage that the backup is up to date.
> 
> While I'm not a gluster expert, I hope this helps!
> Andrew
> 
> 
> On Sat, Jan 15, 2011 at 2:03 AM, Sergiy Lozovsky
> <serge_lozovsky at yahoo.com>
> wrote:
> > Hi,
> >
> > I have two Gluster servers A and B. They are mirrored.
> I mount A. What happens when server A goes down?
> >
> > I would like for my applications to seamlessly use
> data from the Gluster storage B.
> >
> > Thanks,
> >
> > Sergiy.
> >
> >
> >
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> >
>