[Gluster-users] geo-replicated Master Master cluster
Robert Hajime Lanning
lanning at lanning.cc
Sun Nov 25 18:50:21 UTC 2012
On 11/25/12 08:59, Zohair Raza wrote:
> If it could be LAN then, normal replication can this requirement.
> Problem at both side is bandwidth, I need fast read/write access to
> local users and data would later get synchronized with other server.
Unfortunately, Gluster is not going to be a solution for you.
It's design goals have local replicas and an off-site, eventually
consistent, one-way replica as a backup.
The geo-replication is basically a one-way rsync with smart file queuing.
> The all I understand about geo replication is, slave needs to be a third
> machine and if this is the case then I might need 4 machines?
> I have only two machines and I want something like master-master
> concept, I tried that but can not succeed.
Multi-master is Hard(tm) with the same issues as healing a split-brain
How do you merge updates to a file from different sources, without full
understanding of the file format.
Multi-master at the filesystem level usually means synchronous locks and
writes, between all masters.
What you can do with Gluster is create a replicated volume that spans
the sites. Read requests should be satisfied from the local replica
brick, while writes will be synchronous to both sites. With quorum set
correctly, if the link between sites goes down, then only the primary
site will have access to the volume.
King of the Potato People
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