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From Stack <st...@duboce.net>
Subject Re: How to merge regions?
Date Mon, 16 Jul 2012 22:01:35 GMT
On Sat, Jul 14, 2012 at 4:40 PM, Ionut Ignatescu
<ionut.ignatescu@gmail.com> wrote:
> - to merge adjacent empty partitions in a bigger one?
> - to merge empty partitions to non-empty partitions?
> Also, I'm wondering why regions merge is not part of major compactions and
> why it's necessary to stop the
> entire fleet to solve this problem.

Its something that should have been done long time ago but none of us
has taken it on properly.  J-D did an online merge hackup script
attached to the onilne merge issue that worked for our purposes and
helped out some others but beyond that, online merge needs loving.

It should be easier in your case given 40% of the regions are empty.
Are you ok w/ a bit of scripting editing the .META. table?  Are all
40% on the end of the table (given they are aged out)?  Can you just
cut the empty tail off the table by deleting all empty regions from
.META. (and from hdfs) off the end and then just add back a single
region what has a start key of the last non-empty region and an endkey
of the empty row to put back a scan stopper?


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