you got 2 nodes. if the setting dfs.replication is set to 2 and one if faster than the other (or the namenode choose it for reads) it is normal that it acts like this. -- Pierre-Alexandre St-Jean
On Thu, Apr 15, 2010 at 2:54 PM, Geoff Hendrey <[email protected]> wrote: > My Hbase is running on top of an HDFS instance with two datanodes. The > datanodes are on different machines. When I scan an HBase table, the > logs of the two datanodes look very different, and I am wondering why. > One of the nodes shows lots of reads, while the other node shows mainly > "Verification succeeded for blk" > > Here is a snippet from the datanode that shows lots of reads > > 2010-04-15 05:33:02,529 INFO > org.apache.hadoop.hdfs.server.datanode.DataNode.clienttrace: src: > /10.241.6.79:50010, dest: /10.241.6.79:49551, bytes: 140113, op: > HDFS_READ, cliID: DFSClient_-290354743, srvID: > DS-1729078499-10.241.6.79-50010-1271178291303, blockid: > blk_2338086647721232803_30645 > > And here a snippet from the the node that doesn't show any read > activity, and in general isn't very active > > 2010-04-15 05:13:48,858 INFO > org.apache.hadoop.hdfs.server.datanode.DataNode.cli > enttrace: src: /10.241.6.79:52332, dest: /10.241.6.80:50010, bytes: > 162299, op: > HDFS_WRITE, cliID: DFSClient_-290354743, srvID: > DS-642079670-10.241.6.80-50010-1 > 271178858027, blockid: blk_-5368905552009678521_30627 > 2010-04-15 05:13:48,858 INFO > org.apache.hadoop.hdfs.server.datanode.DataNode: Pa > cketResponder 0 for block blk_-5368905552009678521_30627 terminating > 2010-04-15 05:16:47,324 INFO > org.apache.hadoop.hdfs.server.datanode.DataBlockSca > nner: Verification succeeded for blk_1891611024781487471_15100 > > > Any ideas why the activity on the datanode doesn't seem symmetric? Is > there any way I can determine the region boundaries for a table? > > > Geoff Hendrey > > Software Architect > deCarta > Four North Second Street, Suite 950 > San Jose, CA 95113 > office 408.625.3522 > www.decarta.com <blocked::http://www.decarta.com> > > > > >
