No, I had written a huge Map Reduce program which talks with hbase and does a lot of computing using it as a source as well as sink.. One of my colleague saw my code and saw that I had used a lot of static function instead of making use of proper OOP concepts.. He was telling me that it shouldn't be the way I should go about doing it.. But my code works fine.. So, was wondering will I face any problem in the future because of this.. That's all.
Regards, Pavan On Aug 29, 2013 8:11 PM, "Adam Muise" <amu...@hortonworks.com> wrote: > Mappers don't communicate with each other in traditional MapReduce. If you > need something more MPI-ish then look to MPI over YARN or write your own > YARN app. > > If you need multi-threading within the mapper then it is up to you as the > java developer to make it thread safe. Use the concurrent libraries like > anything else and Bob's your uncle. Having overly-complicated mappers can > be difficult to manage however and it kind of misses the mark for MapReduce > problems. > > Maybe if you expand on your use case a bit someone here can provide > specific advice. > > > On Thu, Aug 29, 2013 at 10:33 AM, Pavan Sudheendra <pavan0...@gmail.com>wrote: > >> Hi all, >> >> Is hadoop thread safe? Do mappers make use of threads in any chance? A >> little bit of information on the way they execute in parallel would help me >> out. Thanks. >> >> Regards, >> Pavan >> > > > > -- > * > * > * > * > *Adam Muise* > Solution Engineer > *Hortonworks* > amu...@hortonworks.com > 416-417-4037 > > Hortonworks - Develops, Distributes and Supports Enterprise Apache > Hadoop.<http://hortonworks.com/> > > Hortonworks Virtual Sandbox <http://hortonworks.com/sandbox> > > Hadoop: Disruptive Possibilities by Jeff > Needham<http://hortonworks.com/resources/?did=72&cat=1> > > CONFIDENTIALITY NOTICE > NOTICE: This message is intended for the use of the individual or entity > to which it is addressed and may contain information that is confidential, > privileged and exempt from disclosure under applicable law. If the reader > of this message is not the intended recipient, you are hereby notified that > any printing, copying, dissemination, distribution, disclosure or > forwarding of this communication is strictly prohibited. If you have > received this communication in error, please contact the sender immediately > and delete it from your system. Thank You.
