MultiMaster HBase: --backup really needed ?

[Manuel de Ferran <ma...@gmail.com>]

Greetings,

I'm playing without MultiMaster, and I was wondering if --backup is really
needed.

As far as I have observed, masters race to be the active one. Is there any
drawback in not mentioning --backup on additional nodes ?


Regards,

--
Manuel DE FERRAN

Re: MultiMaster HBase: --backup really needed ?

[Jean-Daniel Cryans <jd...@apache.org>]

The problem with having a bunch of master racing is that it's not evident
for the operator who won, so specifying --backup to all but one master
ensures that you always easily know where the master is.

Relevant code from HMaster.java:

    // If we're a backup master, stall until a primary to writes his address
    if (!c.getBoolean(HConstants.MASTER_TYPE_BACKUP,
      HConstants.DEFAULT_MASTER_TYPE_BACKUP)) {
      return;
    }

J-D


On Mon, Dec 9, 2013 at 9:37 AM, Bryan Beaudreault
<bb...@hubspot.com>wrote:

> I've run HBase from version 0.90.2 to our current 0.94.6 (CDH 4.3) and have
> never specified a --backup option on any of my commands with regard to the
> master.  You're correct that they race to be active, and failover is
> completely automatic in the case of one master going down.
>
> TBH I've never even heard of a --backup argument, so I'm wondering if it is
> something extremely old or extremely new :)
>
>
> On Mon, Dec 9, 2013 at 6:24 AM, Manuel de Ferran
> <ma...@gmail.com>wrote:
>
> > Greetings,
> >
> > I'm playing without MultiMaster, and I was wondering if --backup is
> really
> > needed.
> >
> > As far as I have observed, masters race to be the active one. Is there
> any
> > drawback in not mentioning --backup on additional nodes ?
> >
> >
> > Regards,
> >
> > --
> > Manuel DE FERRAN
> >
>

Re: MultiMaster HBase: --backup really needed ?

[Bryan Beaudreault <bb...@hubspot.com>]

I've run HBase from version 0.90.2 to our current 0.94.6 (CDH 4.3) and have
never specified a --backup option on any of my commands with regard to the
master.  You're correct that they race to be active, and failover is
completely automatic in the case of one master going down.

TBH I've never even heard of a --backup argument, so I'm wondering if it is
something extremely old or extremely new :)


On Mon, Dec 9, 2013 at 6:24 AM, Manuel de Ferran
<ma...@gmail.com>wrote:

> Greetings,
>
> I'm playing without MultiMaster, and I was wondering if --backup is really
> needed.
>
> As far as I have observed, masters race to be the active one. Is there any
> drawback in not mentioning --backup on additional nodes ?
>
>
> Regards,
>
> --
> Manuel DE FERRAN
>