This means that a datanode is asked to receive a new block but the block
already exists.
One case where I have seen this happen is when Namenode is trying to
replicate blocks. Say replication increased from 3 to 20, Namenode asks
might ask multiple datanodes to transfer a block to the same datanode.
Smaller the cluster the cluster more probability that this happens.
What context are you seeing this?
Torsten Curdt wrote:
So we now finally upgraded to 0.14 (more bug reports to come) but could
someone please tell me why we are still seeing this
2007-08-28 08:23:59,836 ERROR org.apache.hadoop.dfs.DataNode:
DataXceiver: java.io.IOException: Block blk_-5226553429149640206 is
valid, and cannot be written to.
at org.apache.hadoop.dfs.FSDataset.writeToBlock(FSDataset.java:515)
at
org.apache.hadoop.dfs.DataNode$DataXceiver.writeBlock(DataNode.java:822)
at
org.apache.hadoop.dfs.DataNode$DataXceiver.run(DataNode.java:727)
at java.lang.Thread.run(Thread.java:595)
...and what it actually means?
cheers
--
Torsten
