On Mon, Jun 21, 2010 at 10:59 PM, Jeff Zhang <zjf...@gmail.com> wrote:
> Hi Hadoop Devs, > > I have one question about the blockReport DataNode send to NameNode. I > think NameNode get the blockReport from DataNode, then it can tell > DataNode which block is invalid and which block should be replicated, > But I look at the source code of method blockReport of NameNode, it > always returns DatanodeCommand.FINALIZE or null. it makes me confused > here. Could anybody help me understand what's the meaning of the code > here ? And how does the NameNode tell DataNode which block should be > delete ? Thanks for your help. > Those commands come in the DatanodeCommand in response to sendHeartbeat. -Todd > > > -- > Best Regards > > Jeff Zhang > -- Todd Lipcon Software Engineer, Cloudera
