Re: HDFS - MapReduce coupling

2011-05-02 Thread James Seigel
If you are pressed for time, you could look at the source code. I believe a huge proportion of the people that could answer your question ( and it isn't a small one ) are sleeping right now. :) Source code is probably your best answer. James Sent from my mobile. Please excuse the typos. On 201

Re: HDFS - MapReduce coupling

2011-05-02 Thread Matthew John
someone kindly give some pointers on this!! On Mon, May 2, 2011 at 12:46 PM, Matthew John wrote: > Any documentations on how the different daemons do the write/read on HDFS > and Local File System (direct), I mean the different protocols used in the > interactions. I basically wanted to figure ou

Re: HDFS - MapReduce coupling

2011-05-02 Thread Matthew John
Any documentations on how the different daemons do the write/read on HDFS and Local File System (direct), I mean the different protocols used in the interactions. I basically wanted to figure out how intricate the coupling between the Storage (HDFS + Local) and other processes in the Hadoop infrast

Re: HDFS - MapReduce coupling

2011-05-01 Thread Ted Dunning
Yes. There is quite a bit of need for the local file system in clustered mode. For one think, all of the shuffle intermediate files are on local disk. For another, the distributed cache is actually stored on local disk. HFDS is a frail vessel that cannot cope with all the needs. On Sun, May 1,

HDFS - MapReduce coupling

2011-05-01 Thread Matthew John
Hi all, 1) I wanted to know how strong the coupling between HDFS and MapReduce (programming abstraction) in Hadoop is. Can someone throw some light on the protocols used between HDFS and JobTracker/TaskTracker/Namenode interactions. Any pointer on this would be of great help! 2) Does the Hadoop s