threads quota is exceeded question

[rauljin]

HI:
       The hadoop cluster is running balance.

       And one datannode 172.16.80.72 is :

Datanode :Not able to copy block -507744952197054725 to /172.16.80.73:51658 
because threads quota is exceeded. 

ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: 
DatanodeRegistration(172.16.80.72:50010, storageID=DS-1202844662-172.16
.80.72-50010-1330656432004, infoPort=50075, ipcPort=50020):DataXceiver
java.io.IOException: Block blk_8443528692263789109_8159545 is not valid.
        at 
org.apache.hadoop.hdfs.server.datanode.FSDataset.getBlockFile(FSDataset.java:734)
        at 
org.apache.hadoop.hdfs.server.datanode.FSDataset.getLength(FSDataset.java:722)
        at 
org.apache.hadoop.hdfs.server.datanode.BlockSender.<init>(BlockSender.java:92)
        at 
org.apache.hadoop.hdfs.server.datanode.DataXceiver.readBlock(DataXceiver.java:172)
        at 
org.apache.hadoop.hdfs.server.datanode.DataXceiver.run(DataXceiver.java:95)
        at java.lang.Thread.run(Thread.java:636)


       And other datanode:


ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: 
DatanodeRegistration(172.16.80.73:50010, 
storageID=DS-1771394657-172.16.80.73-50010-1362474580654, infoPort=50075, 
ipcPort=50020):DataXceiver
java.io.EOFException
        at java.io.DataInputStream.readByte(DataInputStream.java:267)
        at 
org.apache.hadoop.util.DataChecksum.newDataChecksum(DataChecksum.java:84)
        at 
org.apache.hadoop.hdfs.server.datanode.BlockReceiver.<init>(BlockReceiver.java:92)
        at 
org.apache.hadoop.hdfs.server.datanode.DataXceiver.replaceBlock(DataXceiver.java:580)
        at 
org.apache.hadoop.hdfs.server.datanode.DataXceiver.run(DataXceiver.java:115)
        at java.lang.Thread.run(Thread.java:636)

      At that moment , the hdfs is not  avalible.


I restart  the 172.16.80.72 datanode service ,and the service is ok. 



what causes the problem.

Any ideas?
       Thanks!













rauljin