hbase.master.startup.retainassign=false works like a charm. After a restart
all tables are scattered across all region servers.
Thanks!
On Wed, Feb 2, 2011 at 4:06 PM, Stack <st...@duboce.net> wrote:
> On Wed, Feb 2, 2011 at 8:41 PM, Wayne <wav...@gmail.com> wrote:
> > The regions counts are the same per region server which is good. My
> problem
> > is that I have 5 tables and several region servers only serve 1 table's
> > regions.
>
> I wonder if this an effect of our deploying splits to same server as
> split parent? Once the phenomeon goes into effect, we'll not break it
> that I can see (on restart, we try our best in 0.90.0 to redeploy
> regions to where they were running pre-shutdown so we don't lose
> locality).
>
> > I would like to round robin and scatter all tables across all
> > region servers. Basically the distribution is not round-robin enough.
> > Manually moving it is not going to help me. Frankly this goes against the
> > concept of bigger/less regions. Given what I am seeing without an
> > alternative I will reduce the max size of the regions and once I get into
> > the 100s of regions per region server this problem will be resolved. Less
> > regions is dangerous in terms of avoiding hot spots.
> >
> > Is there a way to turn off the memory across restarts of where a region
> > lives? This might help re-balance from scratch.
> >
>
> From AssignmentManager:
>
> 1226 // Determine what type of assignment to do on startup
> 1227 boolean retainAssignment = master.getConfiguration().
> 1228 getBoolean("hbase.master.startup.retainassign", true);
>
> It looks like you could set the above flag in your hbase-site.xml to
> false and that should do it (its on by default).
>
> You could knock a few of your regionservers out of the cluster. Wait
> till regions assigned elsewhere, then bring them back up again. Force
> running of assignment. That might mess stuff up enough?
>
> St.Ack
>
