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HBase >> mail # user >> MultiMaster HBase: --backup really needed ?


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Manuel de Ferran 2013-12-09, 11:24
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Bryan Beaudreault 2013-12-09, 17:37
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Re: MultiMaster HBase: --backup really needed ?
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
<[EMAIL PROTECTED]>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
> <[EMAIL PROTECTED]>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
> >
>