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HBase >> mail # user >> Hbase scans taking a lot of time


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Vibhav Mundra 2013-01-25, 09:10
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Luke Lu 2013-01-25, 17:31
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Vibhav Mundra 2013-01-25, 17:59
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Re: Hbase scans taking a lot of time
Definitely not, you should keep it under 3 maximum. Keep in mind that 1 CF
== 1 Store == at least that many big files to read.
On Fri, Jan 25, 2013 at 6:59 PM, Vibhav Mundra <[EMAIL PROTECTED]> wrote:

> The number of column families I have is 13, which I guess is okie?
>
> -Vibhav
>
>
> On Fri, Jan 25, 2013 at 11:01 PM, Luke Lu <[EMAIL PROTECTED]> wrote:
>
> > You'll have this problem if you have a large number of column families
> > being scanned/populated at the same time. Make sure the data you
> > scan/populate frequently are in the same column family (you can have many
> > columns in a column family). Unlike BigTable/Hypertable which has the
> > concept of locality/access groups, HBase always stores column families in
> > separate files, essentially making column family not only a logic
> grouping
> > mechanism but also a physical locality group.
> >
> >
> > On Fri, Jan 25, 2013 at 1:10 AM, Vibhav Mundra <[EMAIL PROTECTED]> wrote:
> >
> > > I am facing a very strange problem with HBase.
> > >
> > > This what I did:
> > > a) Create a table, using pre partioned splits.
> > > b) Also the column familes are zipped with lzo compression.
> > > c) Using the above configuration I am able to populate 2 million row
> per
> > > min in the Hbase.
> > > d) I have created a table with 300 million odd rows, which roughy took
> > me 3
> > > hours to populate and the data size is of 25GB.
> > >
> > > e) But when I query for data the performance I am getting is very bad.
> > >    Basically this is what I am seeing: High CPU, no disk I/O and
> network
> > > I/O is happening at the rate of 6~7MB secs.
> > >
> > >
> > > Because of this, if I scan the entries of the table using Hive it is
> > taking
> > > ages.
> > > Basically it is taking around 24 hours to scan the table. Any idea, of
> > how
> > > to debug.
> > >
> > >
> > > -Vibhav
> > >
> >
>

--
Adrien Mogenet
06.59.16.64.22
http://www.mogenet.me
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Jean-Marc Spaggiari 2013-01-25, 18:06
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Vibhav Mundra 2013-01-25, 18:14
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Jean-Marc Spaggiari 2013-01-25, 18:23
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lars hofhansl 2013-01-25, 22:00
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lars hofhansl 2013-01-25, 23:56
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Alok Kumar 2013-01-26, 06:07
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Shashwat Shriparv 2013-01-25, 19:13
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Vibhav Mundra 2013-01-25, 19:25
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Shashwat Shriparv 2013-01-25, 19:31
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Vibhav Mundra 2013-01-25, 19:37