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From Michael Segel <michael_se...@hotmail.com>
Subject Re: Region hot spotting
Date Wed, 21 Nov 2012 21:21:34 GMT
Salting is not a good idea and I don't know why people suggest it. 

Case in point.... you want to fetch a single row/record back. Because the salt is arbitrary,
you will need to send N number of get()s one for each salt value. 
Doing a simple one way hash of the data, even appending the data, would be a better idea.
Note that if you are worried about key length, you can do the hash and take the first N bytes
and then append the row to it. It should give you enough of a spread of hash values that you
don't have to worry about hotspots. 

HTH

-Mike

On Nov 21, 2012, at 2:44 AM, ramkrishna vasudevan <ramkrishna.s.vasudevan@gmail.com>
wrote:

> Hi
> This link is pretty much useful.  But still there too it says if you dont
> pre split you need to wait for the salting to help you from hotspotting
> till the region gets splitted.
> 
> Mohammad just pointing this to say the usefulness of presplitting
> definitely your's is a good pointer to Ajay. :)
> 
> Regards
> Ram
> 
> On Wed, Nov 21, 2012 at 1:59 PM, Mohammad Tariq <dontariq@gmail.com> wrote:
> 
>> Hello Ajay,
>> 
>> You can use 'salting' if you don't want to presplit your table. You might
>> this link useful :
>> 
>> http://blog.sematext.com/2012/04/09/hbasewd-avoid-regionserver-hotspotting-despite-writing-records-with-sequential-keys/
>> 
>> HTH
>> 
>> Regards,
>>    Mohammad Tariq
>> 
>> 
>> 
>> On Wed, Nov 21, 2012 at 1:49 PM, ramkrishna vasudevan <
>> ramkrishna.s.vasudevan@gmail.com> wrote:
>> 
>>> Hotspotting is bound to happen until the region starts splitting and gets
>>> assigned to diff region servers.
>>> 
>>> Regards
>>> Ram
>>> 
>>> On Wed, Nov 21, 2012 at 12:49 PM, Ajay Bhosle
>>> <ajay.bhosle@relianceada.com>wrote:
>>> 
>>>> Hi,
>>>> 
>>>> 
>>>> 
>>>> I am inserting some data in hbase which is getting hot spotted in a
>>>> particular server. The format of the row key is (0 or
>>>> 1)|[timestamp]_[sequence].  Basically I want to add log information to
>>>> hbase
>>>> and search the records based on range of dates.
>>>> 
>>>> 
>>>> 
>>>> Can someone suggest any configuration changes or any ideas on how the
>> row
>>>> key should be design. I do not want to specify the splits while
>> creating
>>>> table.
>>>> 
>>>> 
>>>> 
>>>> Thanks
>>>> 
>>>> Ajay
>>>> 
>>>> 
>>>> 
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