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From Gurjeet Singh <gurj...@gmail.com>
Subject Re: Slow full-table scans
Date Tue, 14 Aug 2012 01:10:37 GMT
I am beginning to think that this is a configuration issue on my
cluster. Do the following configuration files seem sane ?

hbase-env.sh     https://gist.github.com/3345338

hbase-site.xml    https://gist.github.com/3345356

Gurjeet

On Mon, Aug 13, 2012 at 5:30 PM, lars hofhansl <lhofhansl@yahoo.com> wrote:
> Only 4% in the 12 node cluster case? I'd guess you're using not more cores then before
(i.e. the parallelizing on the client is bad), or you're IO bound (which is unlikely).
> Are all your regionserver busy in terms of CPU?
>
>
> -- Lars
>
>
>
> ----- Original Message -----
> From: Gurjeet Singh <gurjeet@gmail.com>
> To: user@hbase.apache.org
> Cc:
> Sent: Monday, August 13, 2012 3:12 PM
> Subject: Re: Slow full-table scans
>
> Okay, I just ran this experiment. It did speed things up, but only by
> 4%. This all still seems awfully slow to me - does someone have
> another suggestion ?
>
> Thanks in advance!
> Gurjeet
>
> On Mon, Aug 13, 2012 at 12:51 AM, Gurjeet Singh <gurjeet@gmail.com> wrote:
>> Thanks a lot!
>>
>> On Mon, Aug 13, 2012 at 12:27 AM, Stack <stack@duboce.net> wrote:
>>> On Mon, Aug 13, 2012 at 6:10 AM, Gurjeet Singh <gurjeet@gmail.com> wrote:
>>>> Thanks Lars!
>>>>
>>>> One final question :  is it advisable to issue multiple threads
>>>> against a single HTable instance, like so:
>>>>
>>>> HTable table = ...
>>>> for (i = 0; i < 10; i++) {
>>>>   new ScanThread(table, startRow, endRow, rowProcessor).start();
>>>> }
>>>>
>>>
>>> Make an HTable per thread.  See the class comment:
>>> http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html
>>>
>>> St.Ack
>

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