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From Michael Segel <michael_se...@hotmail.com>
Subject Re: Replication terminology "master-master"
Date Sat, 29 Nov 2014 22:40:55 GMT
Both clusters are alive, but the terms active/passive means who’s serving the data. 

Your ‘master’ is the HBase cluster which is r/w and serving data. 

Your ‘slave’ is the cluster that is passive or only serving read only data. 

To your point that active/passive may be incorrect because you can read from the passive,

Peer to Peer may be incorrect in that while both are peers, you’re actively writing to one,
while the other gets a copy of the data and is passive. 
Understanding that in context a HBase cluster can be active for one data set and passive for

Active/Active would be that I could write to either and there would be some form of eventual

On Nov 28, 2014, at 1:15 AM, Misty Stanley-Jones <mstanleyjones@cloudera.com> wrote:

> I don't think active/passive is what we mean here, since both clusters are
> fully "active" from the perspective of clients, right? The slave cluster is
> not actually read-only, is it?
> On Thu, Nov 27, 2014 at 10:50 PM, Michael Segel <michael_segel@hotmail.com>
> wrote:
>> master - master?
>> Do you mean active - active ?
>> replace master and slave with active and passive.
>> On Nov 25, 2014, at 3:26 AM, Misty Stanley-Jones <
>> mstanleyjones@cloudera.com> wrote:
>>> Hi all,
>>> I think "master-master" is a term that should be re-thought. It is not
>>> really a "type" of replication, but refers to a characteristic of  a
>>> cluster, specifically a cluster which participates in multiple clusters
>>> with different roles -- it is a slave in one cluster and a master in
>>> another cluster. I think with the current terminology, people confuse it
>>> with "cyclical" replication, in which two clusters replicate to each
>> other,
>>> and eventually each has all the data from both.
>>> Since master-master in this sense is really not a type of replication, I
>>> think we should just scrap it. You can have master-slave replication or
>>> cyclical replication, or a combination. With master-slave replication, a
>>> cluster can fulfill both roles at the same time, as long as it is in
>>> different clusters. This is easy to understand as a sort of recursive
>>> cascade.
>>> Am I explaining it right, and what do you guys think about changing our
>>> terminology?
>>> Thanks,
>>> Misty

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