Re: Order preserving partitioning strategy

2010-08-24 Thread Nick Telford
The trade-off is in choosing which property you need: order preservation or
even load distribution.

The only reason a hybrid partitioner doesn't exist is that no one has been
able to create one. If you can create a partitioner that allows ordering
whilst ensuring an even load distribution, by all means contribute it to the
project, we'd all love to have it!

If you do manage such a feat, I'd suggest calling it HolyGrailPartitioner.
:)


Re: [VOTE] 0.6.5 RC3

2010-08-24 Thread Jonathan Ellis
+1

On Tue, Aug 24, 2010 at 9:36 AM, Eric Evans eev...@rackspace.com wrote:

 Some important changes[1] have gone into the 0.6 branch since the
 release, so let's cut this one a little early to get them into the
 hands of users.  I propose the following artifacts for 0.6.5.

 Alright, so in light of CASSANDRA-1377[2] I've re-rolled the artifacts
 as 0.6.5 rc2 (to be released as 0.6.5 if the vote passes).

 As I mentioned previously[3], there was an issue with the fix for the
 fix to CASSANDRA-1377[3], so I propose the follow for 0.6.5.  Third time
 is the charm, right?

 SVN:
 https://svn.apache.org/repos/asf/cassandra/branches/cassandra-...@r988539
 0.6.5-rc3 artifacts: http://people.apache.org/~eevans

 The vote will be open for 72 hours.

 [1]:
 https://svn.apache.org/repos/asf/cassandra/branches/cassandra-0.6/CHANGES.txt
 [2]: https://issues.apache.org/jira/browse/CASSANDRA-1377
 [3]: http://article.gmane.org/gmane.comp.db.cassandra.devel/2105

 --
 Eric Evans
 eev...@rackspace.com





-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com


Re: Order preserving partitioning strategy

2010-08-24 Thread Jonathan Ellis
What are some good papers to read for background?

On Tue, Aug 24, 2010 at 12:26 PM, J. Andrew Rogers
jar.mail...@gmail.com wrote:
 On Mon, Aug 23, 2010 at 8:36 PM, Hien. To Trong hie...@vng.com.vn wrote:
 OrderPreservingPartitioner is efficient range queries but can cause
 unevently distributed data. Does anyone has an idea of a
 HybridPartitioner which takes advantages of both RandomPartitioner
 and OPP, or at least a partitioner trade off between them.


 What you are looking for is skew adaptive partitioning i.e. like a
 B+Tree except distributable.

 A couple different methods for doing something like this exist, but
 you rarely see them and they have their own (different) tradeoffs. To
 the best of my knowledge, implementation requires a fairly deep
 architectural commitment; it is more involved than simply defining a
 partitioning function and the adaptive aspect must be distribution
 friendly. It is an active area of research in the literature with no
 obvious and simple solutions that can be lashed onto a database engine
 as is.

 --
 J. Andrew Rogers




-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com


Re: Having Problems installing Chiton

2010-08-24 Thread Aaron Morton
You need to have the python thrift client and the generated cassandra thrift library in the python path.To get the thrift library I followed this guidehttp://wiki.apache.org/cassandra/InstallThriftThere may be an easier way though.It looks like the Telephus client includes the cassandra package but not the thrift package.AaronOn 24 Aug, 2010,at 05:42 PM, durga devi durgadevi...@gmail.com wrote:Sir/Madam,

I am new to Ubuntu.
I am getting the following Problem when insatlling the chiton in ubuntu
10.4

From this link http://tinyurl.com/24gdgkv
I set the PYHTONPATH as  export
   PYTHONPATH=/home/durga/driftx-
   Telephus-fb32fc7/:/home/durga/driftx-chiton-bd91965/:/usr/bin/python/
   And i run the  /driftx-chiton-bd91965/bin/./chiton-client

   I had the following Problem http://pastebin.com/29T12wef

   I am unble to sort out where this problem is occurring while in
   installation.

Thanks  Regards,
B.Durgadevi