It is cached per input stream - see DFSInputStream.locatedBlocks, prefetchSize, etc.
-Todd On Thu, Jun 10, 2010 at 11:43 PM, Jeff Zhang <zjf...@gmail.com> wrote: > Hi all, > > According the GFS paper claims, GFS will cache meta data in client. > But when I check the source code of hadoop, it seems that hadoop won't > cache it in client side. I just wan to make sure whether I am right ? > And wondering whether there's someone work on it ? One advantage of > caching metadata in client side I can think of is that tasktracker > will fetch job.xml in HDFS. And most of time we will run multiple task > in one node, so if tasktrack cache the metadata, it can reduce the > communication with namenode. > > > > -- > Best Regards > > Jeff Zhang > -- Todd Lipcon Software Engineer, Cloudera
