[openstack-dev] Swift global cluster replication latency...

Clay Gerrard clay.gerrard at gmail.com
Mon Aug 18 18:50:12 UTC 2014


Correct, best-effort.  There is no guarantee or time boxing on cross-region
replication.  The best way to manage cross site replication is by tuning
your replica count to ensure you have primary copies in each region -
eventually.  Possibly evaluate if you need write_affinity at all (you can
always just stream across the WAN on PUT directly into the primary
locations).  Global replication is a great feature, but still ripe for
optimization and turning:

https://review.openstack.org/#/c/99824/

With storage policies you now also have the ability to have a local policy
and global policy giving operators and users even more control about where
they need their objects.  For example you might upload to local policy and
then manage geo-distribution with a COPY request to the global policy.

Do you have a specific use case for geo-distributed objects that you could
share or are you just trying to understand the implementation?

-Clay


On Mon, Aug 18, 2014 at 3:32 AM, Shyam Prasad N <nspmangalore at gmail.com>
wrote:

> Hi,
>
> Went through the following link:
>
> https://swiftstack.com/blog/2012/09/16/globally-distributed-openstack-swift-cluster/
>
> I'm trying to simulate the 2-region 3-replica scenario. The document says
> that the 3rd replica will be asynchronously moved to the remote location
> with a 2-region setup.
>
> What I want to understand is if whether the latency of this asynchronous
> copy can be tweaked/monitored? I couldn't find any configuration parameters
> to tweak this. Do we have such an option? Or is it done on a best-effort
> basis?
>
> Thanks in advance...
>
> --
> -Shyam
>
> _______________________________________________
> OpenStack-dev mailing list
> OpenStack-dev at lists.openstack.org
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20140818/f7342c11/attachment.html>


More information about the OpenStack-dev mailing list