Right, but do you have a specific 4 nodes in mind when you do the write? If not, you may as well write to HDFS from a non-DN node and the block locations will be chosen randomly (with the default policy). This doesn't _guarantee_ that you get different locations for each block allocation, but does make the placement random.
Otherwise, I suppose HDFS-385 is what you need, and your placement class can probably just do a round robin assignment of blocks every time. Just curious - why do you seek this? On Wed, Jul 4, 2012 at 8:31 PM, Giulio D'Ippolito <giulio.dippol...@gmail.com> wrote: > Thanks for the answer, > > My problem is slightly different, let say that I have 6 storage point and i > have 4 files/blocks to insert in the filesystem, i would like that these > blocks will be placed in 4 different storage points, and of course i would > like to do the same for all the next 4 blocks. I'm not interested to the > replicas for the moment. > Thanks > > > Giulio > > > > 2012/7/4 Harsh J <ha...@cloudera.com> >> >> With the default replication/block placement policy, all replicas are >> anyway kept in separate nodes. Is that what you want? >> >> Or are you looking to specify a list of locations you want your blocks >> to go to? For the latter, there's no easy way but you may be >> interested in https://issues.apache.org/jira/browse/HDFS-385. But you >> can't send meta-info with each write with hints even with HDFS-385, >> and may need an external system. >> >> On Wed, Jul 4, 2012 at 4:07 PM, Giulio D'Ippolito >> <giulio.dippol...@gmail.com> wrote: >> > Hello, >> > >> > I would like to insert in the filesystem some blocks, but each of these >> > blocks must be in a different storage point is there a way to specify >> > this? >> > >> > Thanks >> >> >> >> -- >> Harsh J > > -- Harsh J
