Data is streamed directly from the data nodes themselves. The name node is only queried for block locations and other meta data.
Alex On Fri, Apr 10, 2009 at 8:33 AM, Stas Oskin <[email protected]> wrote: > Hi. > > I wanted to verify a point about HDFS client operations: > > When asking for file, is the all communication done through the NameNode? > Or > after being pointed to correct DataNode, does the HDFS works directly > against it? > > Also, NameNode provides a URL named "streamFile" which allows any HTTP > client to get the stored files. Any idea how it's operations compare in > terms of speed to client HDFS access? > > Regards. >
