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HBase, mail # user - Region hot spotting


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Re: Region hot spotting
Mohammad Tariq 2012-11-22, 08:06
Good point Mike.

Regards,
    Mohammad Tariq

On Thu, Nov 22, 2012 at 2:51 AM, Michael Segel <[EMAIL PROTECTED]>wrote:

> 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 <
> [EMAIL PROTECTED]> 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 <[EMAIL PROTECTED]>
> 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 <
> >> [EMAIL PROTECTED]> 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
> >>> <[EMAIL PROTECTED]>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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