You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@hbase.apache.org by Misty Stanley-Jones <ms...@cloudera.com> on 2014/12/10 04:03:40 UTC
Re: Replication terminology "master-master"
Can I get some consensus on what we should be saying about different
replication types? It's a bit over my head and I don't feel comfortable
making a unilateral decision.
On Sun, Nov 30, 2014 at 8:40 AM, Michael Segel <mi...@hotmail.com>
wrote:
> 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, too.
>
> 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 another.
>
> Active/Active would be that I could write to either and there would be
> some form of eventual consistency.
>
> 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
> >>
> >>
>
>
Re: Replication terminology "master-master"
Posted by Misty Stanley-Jones <ms...@cloudera.com>.
There is a patch and a RB request here:
https://issues.apache.org/jira/browse/HBASE-12677
On Wed, Dec 10, 2014 at 8:02 PM, Lars George <la...@gmail.com> wrote:
> +1 :)
>
> On Wed, Dec 10, 2014 at 5:36 AM, Nick Dimiduk <nd...@gmail.com> wrote:
>
> > I suggest we drop the lingo and just say what we mean explicitly: "A
> > cluster may act as both a replication source and destination
> > simultaneously."
> >
> > On Tuesday, December 9, 2014, Misty Stanley-Jones <
> > mstanleyjones@cloudera.com> wrote:
> >
> > > Can I get some consensus on what we should be saying about different
> > > replication types? It's a bit over my head and I don't feel comfortable
> > > making a unilateral decision.
> > >
> > > On Sun, Nov 30, 2014 at 8:40 AM, Michael Segel <
> > michael_segel@hotmail.com
> > > <javascript:;>>
> > > wrote:
> > >
> > > > 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, too.
> > > >
> > > > 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 another.
> > > >
> > > > Active/Active would be that I could write to either and there would
> be
> > > > some form of eventual consistency.
> > > >
> > > > On Nov 28, 2014, at 1:15 AM, Misty Stanley-Jones <
> > > > mstanleyjones@cloudera.com <javascript:;>> 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 <javascript:;>>
> > > > > 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 <javascript:;>> 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
> > > > >>
> > > > >>
> > > >
> > > >
> > >
> >
>
Re: Replication terminology "master-master"
Posted by Lars George <la...@gmail.com>.
+1 :)
On Wed, Dec 10, 2014 at 5:36 AM, Nick Dimiduk <nd...@gmail.com> wrote:
> I suggest we drop the lingo and just say what we mean explicitly: "A
> cluster may act as both a replication source and destination
> simultaneously."
>
> On Tuesday, December 9, 2014, Misty Stanley-Jones <
> mstanleyjones@cloudera.com> wrote:
>
> > Can I get some consensus on what we should be saying about different
> > replication types? It's a bit over my head and I don't feel comfortable
> > making a unilateral decision.
> >
> > On Sun, Nov 30, 2014 at 8:40 AM, Michael Segel <
> michael_segel@hotmail.com
> > <javascript:;>>
> > wrote:
> >
> > > 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, too.
> > >
> > > 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 another.
> > >
> > > Active/Active would be that I could write to either and there would be
> > > some form of eventual consistency.
> > >
> > > On Nov 28, 2014, at 1:15 AM, Misty Stanley-Jones <
> > > mstanleyjones@cloudera.com <javascript:;>> 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 <javascript:;>>
> > > > 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 <javascript:;>> 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
> > > >>
> > > >>
> > >
> > >
> >
>
Re: Replication terminology "master-master"
Posted by Nick Dimiduk <nd...@gmail.com>.
I suggest we drop the lingo and just say what we mean explicitly: "A
cluster may act as both a replication source and destination
simultaneously."
On Tuesday, December 9, 2014, Misty Stanley-Jones <
mstanleyjones@cloudera.com> wrote:
> Can I get some consensus on what we should be saying about different
> replication types? It's a bit over my head and I don't feel comfortable
> making a unilateral decision.
>
> On Sun, Nov 30, 2014 at 8:40 AM, Michael Segel <michael_segel@hotmail.com
> <javascript:;>>
> wrote:
>
> > 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, too.
> >
> > 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 another.
> >
> > Active/Active would be that I could write to either and there would be
> > some form of eventual consistency.
> >
> > On Nov 28, 2014, at 1:15 AM, Misty Stanley-Jones <
> > mstanleyjones@cloudera.com <javascript:;>> 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 <javascript:;>>
> > > 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 <javascript:;>> 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
> > >>
> > >>
> >
> >
>