Hello Ram, This indicates that a client connected to the DataNode's data transfer port but then immediately disconnected before requesting an operation. Sometimes monitoring tools will do this as a liveness check to make sure the DataNode process is running and the port is reachable. The log message is harmless. Apache Hadoop 2.8.0 will ship fix HDFS-9572 to prevent this message from going into the logs.
<https://issues.apache.org/jira/browse/HDFS-9572><https://issues.apache.org/jira/browse/HDFS-9572>https://issues.apache.org/jira/browse/HDFS-9572 --Chris Nauroth From: rammohan ganapavarapu <[email protected]<mailto:[email protected]>> Date: Monday, June 13, 2016 at 2:02 PM To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: Datanode: DataXceiver error processing unknown operation Hi, I am getting this error in datanode, not sure what it means and how to fix it, any one have any suggestions? 2016-06-13 20:59:40,148 ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: localhost:50010:DataXceiver error processing unknown operation src: /1.2.3.4:57308<http://1.2.3.4:57308> dst: /1.2.3.4:50010<http://1.2.3.4:50010> java.io.EOFException Thanks, Ram
