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HBase, mail # dev - Suggestion regarding LB.randomAssignment()


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RE: Suggestion regarding LB.randomAssignment()
Anoop Sam John 2012-03-02, 16:21
Hi Ted,
    Yes the same.
balancer.randomAssignment(servers,state.getRegion() ).

LB interface need a change. Is this ok?

Thanks & Regards
Anoop Sam John

________________________________________
From: Ted Yu [[EMAIL PROTECTED]]
Sent: Friday, March 02, 2012 9:30 PM
To: [EMAIL PROTECTED]
Subject: Re: Suggestion regarding LB.randomAssignment()

Anoop:
Are you suggesting that we pass state.getRegion() into
balancer.randomAssignment() ?
    RegionPlan randomPlan = new RegionPlan(state.getRegion(), null,
      balancer.randomAssignment(servers));

If you have a patch, please upload to JIRA.

Regards

On Fri, Mar 2, 2012 at 6:23 AM, <[EMAIL PROTECTED]> wrote:

> Anoop:
> Can you file a Jira ?
>
> Thanks
>
>
>
> On Mar 2, 2012, at 5:19 AM, Anoop Sam John <[EMAIL PROTECTED]> wrote:
>
> > Hi Devs,
> > In LB there is randomAssignment(List<ServerName> servers) API which will
> be used by AM to assign
> > a region from a down RS. [This will be also used in other cases like
> call to assign() API from client]
> > I feel it would be better to pass the HRegionInfo also into this method.
> When the LB making a choice for a region
> > assignment, when one RS is down, it would be nice that the LB knows for
> which region it is doing this server selection.
> >
> >
> >
> > While one RS down, we wanted the regions to get moved to other RSs but a
> set of regions stay together. We are having custom load balancer but with
> the current way of LB interface this is not possible. Another way is I can
> allow a random assignment of the regions at the RS down time. Later with a
> cluster balance I can balance the regions as I need. But this might make
> regions assign 1st to one RS and then again move to another. Also for some
> time period my business use case can not get satisfied.
> >
> >
> >
> > Also I have seen some issue in JIRA which speaks about making sure that
> Root and META regions always sit in some specific RSs. With the current LB
> API this wont be possible in future.
> >
> >
> >
> >
> >
> > Regards
> > Anoop
>