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From John Vines <john.w.vi...@ugov.gov>
Subject Re: tablet distribution
Date Fri, 13 Jul 2012 21:14:53 GMT
Sounds like you want to use the TableLoadBalancer which will try to even
balance all tablets on a table-by-table basis.
John

On Fri, Jul 13, 2012 at 5:09 PM, ameet kini <ameetkini@gmail.com> wrote:

> Thanks, I was looking for something of the equivalent:
> http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HBaseAdmin.html#move(byte[],
> byte[])
>
> The use case is common enough that there may be some other way to do what
> I want. I have a table that doesn't have its tablets distributed evenly. At
> the system (instance?) level, they are evenly distributed, but not at this
> particular table level.
>
> The docs seem to suggest that pre-splitting a table would automatically
> guarantee that the tablets would be distributed evenly across the nodes of
> the cluster. I see that pre-splitting guarantees that you have that many
> tablets, but not necessarily that they are evenly distributed. Maybe if the
> instance had only one table, then it would be forced to distribute its
> tablets.
>
> Thanks,
> Ameet
>
> PRE-SPLITTING TABLES
>
> Accumulo will balance and distribute tables accross servers. Before a
> table gets large, it will be maintained as a single tablet on a single
> server. This limits the speed at which data can be added or queried to the
> speed of a single node. To improve performance when the a table is new, or
> small, you can add split points and generate new tablets.
>
> In the shell:
>
> root@myinstance> createtable newTableroot@myinstance> addsplits -t newTable g n
t
>
> This will create a new table with 4 tablets. The table will be split on
> the letters g'',n'', and ``t'' which will work nicely if the row data
> start with lower-case alphabetic characters. If your row data includes
> binary information or numeric information, or if the distribution of the
> row information is not flat, then you would pick different split points.
> Now ingest and query can proceed on 4 nodes which can improve performance.
>
>
>
>
>
>
> On Fri, Jul 13, 2012 at 3:04 PM, Eric Newton <eric.newton@gmail.com>wrote:
>
>> Yes, you need to write your own tablet balancer.
>>
>> -Eric
>>
>> On Fri, Jul 13, 2012 at 2:48 PM, ameet kini <ameetkini@gmail.com> wrote:
>> >
>> > Hi,
>> >
>> > Is there a way to force a tablet to move to a particular tablet server?
>> >
>> > Thanks,
>> > Ameet
>>
>
>

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