On Wed, Feb 2, 2011 at 8:41 PM, Wayne <[email protected]> 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
