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
