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Posted to common-user@hadoop.apache.org by ma qiang <ma...@gmail.com> on 2008/02/01 11:35:52 UTC
why read HBase in map function is so slow?
Hi all:
I have a mapreduce program now, and in my map function I need use
some parameters which read from another table in HBase using HTable
class , as a result I find the this program run so slow. Who can tell
me why and how to solve this problem?
Thank you very much!
Best Wishes!
Re: why read HBase in map function is so slow?
Posted by edward yoon <ed...@udanax.org>.
I have a question.
Increased map number would be bring up more speed?
> On 2/2/08, stack <st...@duboce.net> wrote:
> > Are you making the HTable instance every time you do a get? If so,
> > that'll cost.
> > St.Ack
> >
> >
> > ma qiang wrote:
> > > About more than twice. I guess the time of connect to table is too large .
> > >
> > >
> > >
> > > On Feb 1, 2008 8:15 PM, edward yoon <ed...@udanax.org> wrote:
> > >
> > >> How long does it take to get the row data from table?
> > >>
> > >>
> > >> On 2/1/08, ma qiang <ma...@gmail.com> wrote:
> > >>
> > >>> Hi all:
> > >>> I have a mapreduce program now, and in my map function I need use
> > >>> some parameters which read from another table in HBase using HTable
> > >>> class , as a result I find the this program run so slow. Who can tell
> > >>> me why and how to solve this problem?
> > >>> Thank you very much!
> > >>> Best Wishes!
> > >>>
> > >>>
> > >> --
> > >> B. Regards,
> > >> Edward yoon @ NHN, corp.
> > >>
> > >>
> >
> >
>
>
> --
> B. Regards,
> Edward yoon @ NHN, corp.
>
--
B. Regards,
Edward yoon @ NHN, corp.
Re: why read HBase in map function is so slow?
Posted by edward yoon <ed...@udanax.org>.
I have a one question.
Increased map number would be bring up more speed?
On 2/2/08, stack <st...@duboce.net> wrote:
> Are you making the HTable instance every time you do a get? If so,
> that'll cost.
> St.Ack
>
>
> ma qiang wrote:
> > About more than twice. I guess the time of connect to table is too large .
> >
> >
> >
> > On Feb 1, 2008 8:15 PM, edward yoon <ed...@udanax.org> wrote:
> >
> >> How long does it take to get the row data from table?
> >>
> >>
> >> On 2/1/08, ma qiang <ma...@gmail.com> wrote:
> >>
> >>> Hi all:
> >>> I have a mapreduce program now, and in my map function I need use
> >>> some parameters which read from another table in HBase using HTable
> >>> class , as a result I find the this program run so slow. Who can tell
> >>> me why and how to solve this problem?
> >>> Thank you very much!
> >>> Best Wishes!
> >>>
> >>>
> >> --
> >> B. Regards,
> >> Edward yoon @ NHN, corp.
> >>
> >>
>
>
--
B. Regards,
Edward yoon @ NHN, corp.
Re: why read HBase in map function is so slow?
Posted by stack <st...@duboce.net>.
Are you making the HTable instance every time you do a get? If so,
that'll cost.
St.Ack
ma qiang wrote:
> About more than twice. I guess the time of connect to table is too large .
>
>
>
> On Feb 1, 2008 8:15 PM, edward yoon <ed...@udanax.org> wrote:
>
>> How long does it take to get the row data from table?
>>
>>
>> On 2/1/08, ma qiang <ma...@gmail.com> wrote:
>>
>>> Hi all:
>>> I have a mapreduce program now, and in my map function I need use
>>> some parameters which read from another table in HBase using HTable
>>> class , as a result I find the this program run so slow. Who can tell
>>> me why and how to solve this problem?
>>> Thank you very much!
>>> Best Wishes!
>>>
>>>
>> --
>> B. Regards,
>> Edward yoon @ NHN, corp.
>>
>>
Re: why read HBase in map function is so slow?
Posted by ma qiang <ma...@gmail.com>.
About more than twice. I guess the time of connect to table is too large .
On Feb 1, 2008 8:15 PM, edward yoon <ed...@udanax.org> wrote:
> How long does it take to get the row data from table?
>
>
> On 2/1/08, ma qiang <ma...@gmail.com> wrote:
> > Hi all:
> > I have a mapreduce program now, and in my map function I need use
> > some parameters which read from another table in HBase using HTable
> > class , as a result I find the this program run so slow. Who can tell
> > me why and how to solve this problem?
> > Thank you very much!
> > Best Wishes!
> >
>
>
> --
> B. Regards,
> Edward yoon @ NHN, corp.
>
Re: why read HBase in map function is so slow?
Posted by edward yoon <ed...@udanax.org>.
How long does it take to get the row data from table?
On 2/1/08, ma qiang <ma...@gmail.com> wrote:
> Hi all:
> I have a mapreduce program now, and in my map function I need use
> some parameters which read from another table in HBase using HTable
> class , as a result I find the this program run so slow. Who can tell
> me why and how to solve this problem?
> Thank you very much!
> Best Wishes!
>
--
B. Regards,
Edward yoon @ NHN, corp.