Correct. The blocks will be read sequentially.
> On Jun 26, 2019, at 10:51 AM, Daegyu Han <hdg9...@gmail.com> wrote: > > Thank you for your response. > > Assuming HDFS blocks (blk1~blk8) for file input.dat are on the local data > node, > does the map task read these blocks sequentially when trying to read local > blocks? > > > 2019년 6월 27일 (목) 02:45, Arpit Agarwal <aagar...@cloudera.com > <mailto:aagar...@cloudera.com>>님이 작성: > HDFS reads blocks sequentially. We can implement a multi-threaded block > reader in theory. > > > > On Jun 26, 2019, at 5:05 AM, Daegyu Han <hdg9...@gmail.com > > <mailto:hdg9...@gmail.com>> wrote: > > > > Hi all, > > > > Assuming HDFS has a 1GB file input.dat and a block size of 128MB. > > > > Can the user read multithreaded when reading the input.dat file? > > > > In other words, is not the block being read sequentially, but reading > > multiple blocks at the same time? > > > > If not, is it difficult to implement a multi-threaded block read? > > > > Best Regards, > > Daegyu > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: user-unsubscr...@hadoop.apache.org > > <mailto:user-unsubscr...@hadoop.apache.org> > > For additional commands, e-mail: user-h...@hadoop.apache.org > > <mailto:user-h...@hadoop.apache.org> > > >
