im a newbie but maybe this will also add some value... it is my understanding that mapreduce is like a distributed "group by" statement
when you run a statement like this against your petabyes of dataset it can take a long time.. first and foremost because the first thing you have to do before you apply the group by logic is to read the data off disk. if your disk reads at 100/MBs then you can do the math. The time frame that this query will run take at least this long to complete. If you need this info really fast like in the next hour to support i dunno personalization features on a ecommerce site or month end report that needs to be complete in 2 hours. Then it would be nice to put equal parts of your data on 100s of disks and run the same algorithm in parralel but thats just if your bottleneck is disk. what if your dataset is relatively small but calculations done on each element coming in is large so therefore your bottleneck there is CPU power there are alot of bottlenecks you could run into. number of threads memory latency of remote apis or remote database you hit as you analyze the data Theres a book called programming collective intelligence from oreilly that should help you out too http://shop.oreilly.com/product/9780596529321.do On Tue, May 21, 2013 at 11:02 PM, Sai Sai <saigr...@yahoo.in> wrote: > Excellent Sanjay, really excellent input. Many Thanks for this input. > I have been always thinking about some ideas but never knowing what to > proceed with. > Thanks again. > Sai > > ------------------------------ > *From:* Sanjay Subramanian <sanjay.subraman...@wizecommerce.com> > *To:* "user@hadoop.apache.org" <user@hadoop.apache.org> > *Sent:* Tuesday, 21 May 2013 11:51 PM > *Subject:* Re: Project ideas > > +1 > > My $0.02 is look look around and see problems u can solve…Its better to > get a list of problems and see if u can model a solution using map-reduce > framework > > An example is as follows > > PROBLEM > Build a Cars Pricing Model based on advertisements on Craigs list > > OBJECTIVE > Recommend a price to the Craigslist car seller when the user gives info > about make,model,color,miles > > DATA required > Collect RSS feeds daily from Craigs List (don't pound their website , else > they will lock u down) > > DESIGN COMPONENTS > - Daily RSS Collector - pulls data and puts into HDFS > - Data Loader - Structures the columns u need to analyze and puts into HDFS > - Hive Aggregator and analyzer - studies and queries data and brings out > recommendation models for car pricing > - REST Web service to return query results in XML/JSON > - iPhone App that talks to web service and gets info > > There u go…this should keep a couple of students busy for 3 months > > I find this kind of problem statement and solutions simpler to > understand because its all there in the real world ! > > An example of my way of thinking led to me founding this non profit > called www.medicalsidefx.org that gives users valuable metrics regarding > medical side fx. > It uses Hadoop to aggregate , Lucene to search….This year I am redesigning > the core to use Hive :-) > > Good luck > > Sanjay > > > > > > From: Michael Segel <michael_se...@hotmail.com> > Reply-To: "user@hadoop.apache.org" <user@hadoop.apache.org> > Date: Tuesday, May 21, 2013 6:46 AM > To: "user@hadoop.apache.org" <user@hadoop.apache.org> > Subject: Re: Project ideas > > Drink heavily? > > Sorry. > > Let me rephrase. > > Part of the exercise is for you, the student to come up with the idea. > Not solicit someone else for a suggestion. This is how you learn. > > The exercise is to get you to think about the following: > > 1) What is Hadoop > 2) How does it work > 3) Why would you want to use it > > You need to understand #1 and #2 to be able to #3. > > But at the same time... you need to also incorporate your own view of > the world. > What are your hobbies? What do you like to do? > What scares you the most? What excites you the most? > Why are you here? > And most importantly, what do you think you can do within the time period. > (What data can you easily capture and work with...) > > Have you ever seen 'Eden of the East' ? ;-) > > HTH > > > On May 21, 2013, at 8:35 AM, Anshuman Mathur <ans...@gmail.com> wrote: > > Hello fellow users, > We are a group of students studying in National University of Singapore. > As part of our course curriculum we need to develop an application using > Hadoop and map-reduce. Can you please suggest some innovative ideas for > our project? > Thanks in advance. > Anshuman > > > > CONFIDENTIALITY NOTICE > ====================== > This email message and any attachments are for the exclusive use of the > intended recipient(s) and may contain confidential and privileged > information. Any unauthorized review, use, disclosure or distribution is > prohibited. If you are not the intended recipient, please contact the > sender by reply email and destroy all copies of the original message along > with any attachments, from your computer system. If you are the intended > recipient, please be advised that the content of this message is subject to > access, review and disclosure by the sender's Email System Administrator. > > >
