If you run any HDFS client operations on your NameNode box or if another service running on the NameNode machine accesses HDFS, they will register as a Read/Write client traces on the DataNodes. It isn't the NameNode that reads the blocks usually.
On Mon, Oct 8, 2012 at 12:30 PM, Li Shengmei <lisheng...@ict.ac.cn> wrote: > Hi, all > > I read the namenode.log and found there are HDFS_READ/WRITE > operations from namenode to datanode. That is to say, the datanodes read > blocks from namenode. I want to know what kind of blocks that the datanodes > read from namenode? Should the blocks stored in datanodes, shouldn't that? > > > > Thanks > > May > > > > > -- Harsh J
