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/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
