Andrew Purtell wrote:
..
To be a bit more specific, I have three things in mind:
1) The ability to fix a given key range to a region. This
would both assign a range to a given region, and also
disable splitting over that range. Aside from API changes,
ideally there would be a HBase shell command to support
this.
Do you really want to be able to set the start and end key on a single
region or is it more that you want the japanese info to be kept in
regions that are hosted at the japanese datacenter, the european regions
in the european datacenter, etc?
...
As I am still coming up to speed on Hadoop and HBase and
the code base, I kindly ask for the answers to two
questions.
First: How invasive to the HBase master/region model is the
concept of specifying constraints on data mobility?
Hbase has no notion of constraining data mobility currently. To add it,
I'd imagine you'd want to enhance the master region assignment algorithm
so it takes into consideration geographic location.
Second: How difficult would the modifications may be to
accomplish?
It has been a (secondary) intent that hbase servers can be sub-classed
so alternative or enhanced implementations can be plugged in. This
facility has been little exercised. Let us know if there are any
changes you need made to get you going.
St.Ack
