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From: Michael Segel <michael_segel@hotmail.com>
To: <user@hbase.apache.org>
Subject: RE: Best way to get multiple non-sequential rows
Date: Wed, 25 Aug 2010 05:53:54 -0500
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Jonathan=2C

Ok=2C that makes some sense...
So you would have some method mget(fetchKeyList=2Cnumthreads) returning res=
ultList[].

So what's thread safe these days?=20

-Mike

> From: jgray@facebook.com
> To: user@hbase.apache.org
> Subject: RE: Best way to get multiple non-sequential rows
> Date: Wed=2C 25 Aug 2010 03:52:38 +0000
>=20
> Michael=2C
>=20
> MultiGet is about performing a set of Get operations in parallel from the=
 client.  So it buys you potential performance benefits from the concurrenc=
y/distribution of your operations.
>=20
> Roughly=2C you would bucket the gets according to their region and region=
server.  Then spawn a thread for each RS and fire off the Gets concurrently=
.
>=20
> If I have 100 Gets to perform on a random set of keys=2C assuming each ge=
t takes 10ms=2C doing them sequentially will take 1 second.  Other factors =
and RS concurrency aside=2C with MultiGet on a 10 node cluster=2C the total=
 time would be reduced to 100ms. With 50 nodes=2C 20ms.
>=20
> JG
>=20
>=20
> > -----Original Message-----
> > From: Michael Segel [mailto:michael_segel@hotmail.com]
> > Sent: Tuesday=2C August 24=2C 2010 7:53 PM
> > To: user@hbase.apache.org
> > Subject: RE: Best way to get multiple non-sequential rows
> >=20
> >=20
> > Igor=2C
> >=20
> > What does this really buy you?
> >=20
> > I'm trying to figure out a use case that would show a benefit from just
> > fetching the rows individually. Since the rows are not contiguous=2C th=
e
> > odds of the next row you want being in cache are going to slight to
> > most likely not. =3B-)
> >=20
> > Can you give a use case where having a 'multi-get' will make life
> > easier?
> >=20
> > Thx
> >=20
> > -Mike
> >=20
> >=20
> > > Date: Wed=2C 25 Aug 2010 07:17:13 +0600
> > > Subject: Re: Best way to get multiple non-sequential rows
> > > From: imyousuf@gmail.com
> > > To: user@hbase.apache.org
> > >
> > > Thanks Igor=2C I will have a look at it.
> > >
> > > /Imran
> > >
> > > On Tue=2C Aug 24=2C 2010 at 10:36 PM=2C Igor Ranitovic <iranitov@gmai=
l.com>
> > wrote:
> > > > Take a look at
> > > > https://issues.apache.org/jira/browse/HBASE-1845
> > > >
> > > > As an HBase user=2C multi gets is something that I have been lookin=
g
> > forward
> > > > to for some time now. If there is enough interest it would be great
> > if this
> > > > becomes part of 0.90.
> > > >
> > > > Take care=2C
> > > > i.
> > > >
> > > > Imran M Yousuf wrote:
> > > >>
> > > >> Hi=2C
> > > >>
> > > >> I am using the HBase client API to interact with HBase. I have
> > noticed
> > > >> that HTableInterface has operations such as put(List<Put>)=2C
> > > >> delete(List<Delete>)=2C but there is no similar method for Get.
> > Using
> > > >> scan it is possible to load a range of rows=2C i.e. sequential row=
s.
> > My
> > > >> question is -
> > > >> how would it be most efficient to load N non-sequential rows?
> > > >>
> > > >> Currently I am using get(Get) method N times.
> > > >>
> > > >
> > > >
> > >
> > >
> > >
> > > --
> > > Imran M Yousuf
> > > Blog: http://imyousuf-tech.blogs.smartitengineering.com/
> > > Mobile: +880-1711402557
> >=20
 		 	   		  =

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