From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Kampe Subject: Re: geo replication Date: Wed, 09 Jan 2013 13:32:03 -0800 Message-ID: <50EDE1D3.3080803@inktank.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pb0-f49.google.com ([209.85.160.49]:34779 "EHLO mail-pb0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933329Ab3AIVcE (ORCPT ); Wed, 9 Jan 2013 16:32:04 -0500 Received: by mail-pb0-f49.google.com with SMTP id un15so1191800pbc.22 for ; Wed, 09 Jan 2013 13:32:04 -0800 (PST) In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Gandalf Corvotempesta Cc: ceph-devel@vger.kernel.org Right now, your only option is synchronous replication, which happens at the speed of the slowest OSD ... so unless your WAN links are fast and fat, it comes at non-negligible performance penalty. We will soon be sending out a proposal for an asynchronous replication mechanism with eventual consistency for the RADOS Gateway ... but that is a somewhat simpler problem (immutable objects, good change lists, and a WAN friendly protocol). Asynchronous RADOS replication is definitely on our list, but more complex and farther out. On 01/09/2013 01:19 PM, Gandalf Corvotempesta wrote: > probably this was already asked before but i'm unable to find any answer. > Is possible to replicate a cluster geografically? > > GlusterFS does this with rsync (i think called automatically on every > file write), does cheph do something similiar? > > I don't think that using multiple geographically distributed OSD with > 10-15ms of latency will be good