I have written a mistake : of course SpecificRecord is in the cassandra API but my question is : why i have this problem ? or Is the an another way to write back the result ?
Thanks 2011/5/30 Laurent Hatier <[email protected]> > Hi everybody, > > I have a little problem with cassandra-all jar file : when i want to write > back the result of the MapReduce in DB, he says me that the SpecificRecord > class (Hector API) is not found... I have already check this dependency and > it's ok. Do I have to use the Cassandra API or it's a technical problem ? > > Thanks > > > 2011/5/27 Laurent Hatier <[email protected]> > >> Of couurse !!! It's logical. >> Thank you John. >> >> 2011/5/27 John Armstrong <[email protected]> >> >>> On Fri, 27 May 2011 13:52:04 +0200, Laurent Hatier >>> <[email protected]> wrote: >>> > I'm a newbie with Hadoop/MapReduce. I've a problem with hadoop. I set >>> some >>> > variables in the run function but when Map running, he can't get the >>> value >>> > of theses variables... >>> > If anyone knows the solution :) >>> >>> By the "run function" do you mean the main method that launches the >>> map/reduce job? It's no surprise that the mappers (and reducers) won't >>> know those variables, because they run as completely separate tasks. >>> >>> If you're computing something in the setup method for use in the mappers >>> or reducers you'll have to pass that information along somehow. If it's >>> a >>> String (or something that can easily be made into a String, like an int) >>> you can set it as a property in the job's Configuration. For more >>> complicated data you'll have to serialize it to a file, place the file >>> into >>> the distributed cache, and then deserialize the data within the mapper or >>> reducer's setup method. >>> >>> Of course, if the computation is less complicated/time consuming than the >>> deserialization process, you may as well just recompute the data in each >>> mapper or reducer. >>> >> >> >> >> -- >> Laurent HATIER >> Étudiant en 2e année du Cycle Ingénieur à l'EISTI >> > > > > -- > Laurent HATIER > Étudiant en 2e année du Cycle Ingénieur à l'EISTI > -- Laurent HATIER Étudiant en 2e année du Cycle Ingénieur à l'EISTI
