About the HDFS_READ/WRITE blocks from namenode to datanode

[Li Shengmei <li...@ict.ac.cn>]

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

 

 

Re: About the HDFS_READ/WRITE blocks from namenode to datanode

[Harsh J <ha...@cloudera.com>]

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 <li...@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