Hi Shrijeet, Helped a lot! Thanks!
Now, the only think I need is to know where's the best place to put my JAR on the server. Should I put it on the hadoop lib directory? Or somewhere on the HBase structure? Thanks, JM 2012/10/29, Shrijeet Paliwal <[email protected]>: > In line. > > On Mon, Oct 29, 2012 at 8:11 AM, Jean-Marc Spaggiari < > [email protected]> wrote: > >> I'm replying to myself ;) >> >> I found "cleanup" and "setup" methods from the TableMapper table. So I >> think those are the methods I was looking for. I will init the >> HTablePool there. Please let me know if I'm wrong. >> >> Now, I still have few other questions. >> >> 1) context.getCurrentValue() can throw a InterrruptedException, but >> when can this occur? Is there a timeout on the Mapper side? Of it's if >> the region is going down while the job is running? >> > > You do not need to call context.getCurrentValue(). The 'value' argument to > map method[1] has the information you are looking for. > > >> 2) How can I pass parameters to the Map method? Can I use >> job.getConfiguration().put to add some properties there, can get them >> back in context.getConfiguration.get? >> > > Yes, thats how it is done. > > >> 3) What's the best way to log results/exceptions/traces from the map >> method? >> > > In most cases, you'll have mapper and reducer classes as nested static > classes within some enclosing class. You can get handle to the Logger from > the enclosing class and do your usual LOG.info, LOG.warn yada yada. > > Hope it helps. > > [1] map(KEYIN key, *VALUEIN value*, Context context) > >> >> I will search on my side, but some help will be welcome because it >> seems there is not much documentation when we start to dig a bit :( >> >> JM >> >> 2012/10/27, Jean-Marc Spaggiari <[email protected]>: >> > Hi, >> > >> > I'm thinking about my firs MapReduce class and I have some questions. >> > >> > The goal of it will be to move some rows from one table to another one >> > based on the timestamp only. >> > >> > Since this is pretty new for me, I'm starting from the RowCounter >> > class to have a baseline. >> > >> > There are few things I will have to update. First, the >> > createSumittableJob method to get timestamp range instead of key >> > range, and "play2 with the parameters. This part is fine. >> > >> > Next, I need to update the map method, and this is where I have some >> > questions. >> > >> > I'm able to find the timestamp of all the cf:c from the >> > context.getCurrentValue() method, that's fine. Now, my concern is on >> > the way to get access to the table to store this field, and the table >> > to delete it. Should I instantiate an HTable for the source table, and >> > execute and delete on it, then do an insert on another HTable >> > instance? Should I use an HTablePool? Also, since I’m already on the >> > row, can’t I just mark it as deleted instead of calling a new HTable? >> > >> > Also, instead of calling the delete and put one by one, I would like >> > to put them on a list and execute it only when it’s over 10 members. >> > How can I make sure that at the end of the job, this is flushed? Else, >> > I will lose some operations. Is there a kind of “dispose” method >> > called on the region when the job is done? >> > >> > Thanks, >> > >> > JM >> > >> >
