Hi Lukas, HDFS read-ahead/write caching is provided by DFSInputStream and DFSOutputStream respectively (see CachingStrategy).
Other file system providers need to implement their own caching strategy. FileSystem#open and FileContext#open just return a seekable input stream with no read-ahead assumptions. -Arpit On Tue, Aug 27, 2013 at 7:58 AM, Lukas Kairies < [email protected]> wrote: > Hello, > > I know that the client caches write requests before they send to a > datanode and that the client uses read-ahead, but where exactly is this > implemented, Hadoop or HDFS? Or better question, will write cache and > read-ahead also available when Hadoop uses another filesysten than HDFS? > > Thanks, > Lukas K. > > > -- CONFIDENTIALITY NOTICE NOTICE: This message is intended for the use of the individual or entity to which it is addressed and may contain information that is confidential, privileged and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, you are hereby notified that any printing, copying, dissemination, distribution, disclosure or forwarding of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and delete it from your system. Thank You.
