Hi, I run my hadoop job and when I opened my datanode logs I found many of these messages :
2012-01-17 23:59:32,756 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: java.net.SocketTimeoutException: Call to uvm12dk/172.16.4.147:9000 failed on socket timeout exception: java.net.SocketTimeoutException: 20000 millis timeout while waiting for channel to be ready for connect. ch : java.nio.channels.SocketChannel[connection-pending remote=uvm12dk/ 172.16.4.147:9000] at org.apache.hadoop.ipc.Client.wrapException(Client.java:771) at org.apache.hadoop.ipc.Client.call(Client.java:743) at org.apache.hadoop.ipc.RPC$Invoker.invoke(RPC.java:220) at $Proxy4.sendHeartbeat(Unknown Source) at org.apache.hadoop.hdfs.server.datanode.DataNode.offerService(DataNode.java:702) at org.apache.hadoop.hdfs.server.datanode.DataNode.run(DataNode.java:1186) at java.lang.Thread.run(Thread.java:662) Caused by: java.net.SocketTimeoutException: 20000 millis timeout while waiting for channel to be ready for connect. ch : java.nio.channels.SocketChannel[connection-pending remote=uvm12dk/ 172.16.4.147:9000] at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:213) at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:404) at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:304) at org.apache.hadoop.ipc.Client$Connection.access$1700(Client.java:176) at org.apache.hadoop.ipc.Client.getConnection(Client.java:860) at org.apache.hadoop.ipc.Client.call(Client.java:720) ... 5 more 2012-01-17 23:59:53,774 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: uvm12dk/172.16.4.147:9000. Already tried 0 time(s). Is this message means that my slave nodes didn't do any work? Thanks.