instanceof is slow as hell, but if you have no other solution then this is
okay.

2) What is like the standard way to load matrices in different nodes with a
> custom partitioning scheme


It is depending on your algorithm needs, but I think you will need to
implement your own partitioner, since HashPartitioning may not apply to
this ICF.
Generally you need to use the input system to read a part of a matrix into
each peer.

We also script a mapreduce job that will create random input for x GB to
check scalability.
Here is that for graphs: https://issues.apache.org/jira/browse/HAMA-558
But I think this is easily extendable to matrices. There is an issue for
that as well, I don't know how far Mikalai came with that.

BTW your code looks good ;)

Can we use this for https://issues.apache.org/jira/browse/HAMA-94 or
https://issues.apache.org/jira/browse/HAMA-553 ? Would be a great addition
if it works!

Greetings from Germany,
Thomas

2012/5/17 Aditya Sarawgi <[email protected]>

> Thanks Thomas.
> I am actually using tags for something else. So for now using instanceof is
> just fine with me.
>
> I had a couple of more questions, regarding benchmarking stuff on hama. I
> have a working implementation  of
> Parallel row based icf that given a n x n matrix returns a decomposed n x p
> matrix.
>
>
> https://github.com/truncs/hello-world/blob/master/shttps://issues.apache.org/jira/browse/HAMA-558rc/main/java/edu/sunysb/cs/Icf.java<https://github.com/truncs/hello-world/blob/master/src/main/java/edu/sunysb/cs/Icf.java>
>
> Now I would like to test this on a big input and possibly in full
> distributed mode, so I was wondering how do
> people usually do these sort of benchmarking.
>
> Specifically,
> 1) Do they setup a cluster on AWS ?
> 2) What is like the standard way to load matrices in different nodes with a
> custom partitioning scheme
> 3) Is there anything else that I should know
>
> On Thu, May 17, 2012 at 3:20 AM, Thomas Jungblut <
> [email protected]> wrote:
>
> > Hi Aditya,
> >
> > that's where the concept of Message Tagging comes into play. You have
> tags
> > in each message which are hardcoded as Strings.
> > But as Edward told you can use GenericWritable or ObjectWritable instead,
> > so they will tag your messages with the classnames and give you the
> correct
> > class.
> >
> > Is there any way by which I can pop from the receive queue ?
> >
> >
> > peer.getCurrentMessage() is popping from the received queue.
> >
> > 2012/5/17 Aditya Sarawgi <[email protected]>
> >
> > > Hi,
> > >
> > > But thats not the only problem, consider this case
> > > that there are variable number of messages being sent, so I would have
> to
> > > maintain
> > > counts for each peer pointing to the last unread message.
> > >
> > > Is there any way by which I can pop from the receive queue ?
> > >
> > >
> > > On Wed, May 16, 2012 at 10:23 PM, Suraj Menon <[email protected]
> > > >wrote:
> > >
> > > > Hi,
> > > >
> > > > Please take a look at this snippet of code copied and modified from
> > > > Mapper class to implement your scenario. -
> > > >
> > > >
> > >
> >
> https://github.com/ssmenon/hama/edit/master/hama-mapreduce/src/org/apache/hama/computemodel/mapreduce/Trials.java
> > > > Between lines 233 to 245 I am able to send different type of
> messages.
> > > > With type checks and generics you shouldn't be encountering Classcast
> > > > exception at receiving end too. I am yet to test the next superstep,
> > > > shall update you with sample code for the next superstep mimicking
> > > > your scenario for receiving.
> > > >
> > > > For elegance, we have an experimental Superstep#compute
> > > > API(org.apache.hama.bsp.Superstep). I have encountered an issue in
> job
> > > > submission framework with this method in distributed mode; fix for
> > > > this would be pushed to trunk in next few hours. You can still run it
> > > > using  LocalBSPRunner for now.
> > > >
> > > > -Suraj
> > > >
> > > > On Wed, May 16, 2012 at 9:18 PM, Aditya Sarawgi
> > > > <[email protected]> wrote:
> > > > > Hi Edward,
> > > > >
> > > > > Yes that is what I did
> > > > > I wrote an ArrayMessage class (doesn't use generics for now but can
> > be
> > > > > converted easily)
> > > > >
> > > >
> > >
> >
> https://github.com/truncs/hello-world/blob/master/src/main/java/edu/sunysb/cs/ArrayMessage.java
> > > > >
> > > > > But the problem is that I am sending a IntegerMessage before and
> > after
> > > > > reading the IntegerMessage I am sending
> > > > > an ArrayMessage but the previous IntegerMessage is still there.
> > > > >
> > > > > On Wed, May 16, 2012 at 8:34 PM, Edward J. Yoon <
> > [email protected]
> > > > >wrote:
> > > > >
> > > > >> Hi,
> > > > >>
> > > > >> To send or receive multiple Message types, I think you can use
> > > > >> GenericWritable. You can also implement your own GenericMessage
> and
> > > > >> contribute it to our project!
> > > > >>
> > > > >> Hope this helps you.
> > > > >>
> > > > >> On Thu, May 17, 2012 at 7:48 AM, Aditya Sarawgi
> > > > >> <[email protected]> wrote:
> > > > >> > Hi Guys,
> > > > >> >
> > > > >> > I am wondering how do the receive queues in hama work. Consider
> > this
> > > > case
> > > > >> > that I want to sent a different type of BSPMessage in 2
> > consecutive
> > > > >> > superstep.
> > > > >> > In this first superstep I am sending IntMessage and in the next
> > one
> > > I
> > > > am
> > > > >> > sending a ArrayMessage ( custom message class).
> > > > >> >
> > > > >> > Now in the second super step when I do a
> > > > >> >  while ((arrayMessage = (ArrayMessage) peer.getCurrentMessage())
> > !=
> > > > >> null) {
> > > > >> >
> > > > >> > it is throwing a java.lang.ClassCastException, which is obvious
> > > since
> > > > its
> > > > >> > trying to cast IntMessage to ArrayMessage.
> > > > >> > I thought the message is dropped from the queue after it is
> read,
> > is
> > > > this
> > > > >> > not the case ?
> > > > >> > And if it is not, how can this be handled elegantly ?
> > > > >> >
> > > > >> > --
> > > > >> > Cheers,
> > > > >> > Aditya Sarawgi
> > > > >>
> > > > >>
> > > > >>
> > > > >> --
> > > > >> Best Regards, Edward J. Yoon
> > > > >> @eddieyoon
> > > > >>
> > > > >
> > > > >
> > > > >
> > > > > --
> > > > > Cheers,
> > > > > Aditya Sarawgi
> > > >
> > >
> > >
> > >
> > > --
> > > Cheers,
> > > Aditya Sarawgi
> > >
> >
> >
> >
> > --
> > Thomas Jungblut
> > Berlin <[email protected]>
> >
>
>
>
> --
> Cheers,
> Aditya Sarawgi
>



-- 
Thomas Jungblut
Berlin <[email protected]>

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