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>
