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Xiang Li commented on HDFS-8738: -------------------------------- Agree with Arpit. Add the link as a dup of HDFS-9572. > Limit Exceptions thrown by DataNode when a client makes socket connection and > sends an empty message > ---------------------------------------------------------------------------------------------------- > > Key: HDFS-8738 > URL: https://issues.apache.org/jira/browse/HDFS-8738 > Project: Hadoop HDFS > Issue Type: Bug > Components: datanode > Affects Versions: 2.7.1 > Reporter: Rajesh Kartha > Assignee: Rajesh Kartha > Priority: Minor > Attachments: HDFS-8738.001.patch > > > When a client creates a socket connection to the Datanode and sends an empty > message, the datanode logs have exceptions like these: > 2015-07-08 20:00:55,427 ERROR datanode.DataNode (DataXceiver.java:run(278)) - > bidev17.rtp.ibm.com:50010:DataXceiver error processing unknown operation > src: /127.0.0.1:41508 dst: /127.0.0.1:50010 > java.io.EOFException > at java.io.DataInputStream.readShort(DataInputStream.java:315) > at > org.apache.hadoop.hdfs.protocol.datatransfer.Receiver.readOp(Receiver.java:58) > at > org.apache.hadoop.hdfs.server.datanode.DataXceiver.run(DataXceiver.java:227) > at java.lang.Thread.run(Thread.java:745) > 2015-07-08 20:00:56,671 ERROR datanode.DataNode (DataXceiver.java:run(278)) - > bidev17.rtp.ibm.com:50010:DataXceiver error processing unknown operation > src: /127.0.0.1:41509 dst: /127.0.0.1:50010 > java.io.EOFException > at java.io.DataInputStream.readShort(DataInputStream.java:315) > at > org.apache.hadoop.hdfs.protocol.datatransfer.Receiver.readOp(Receiver.java:58) > at > org.apache.hadoop.hdfs.server.datanode.DataXceiver.run(DataXceiver.java:227) > at java.lang.Thread.run(Thread.java:745) > These can fill up the logs and was recently noticed with an Ambari 2.1 based > install which tries to check if the datanode is up. > Can be easily reproduced with a simple Java client creating a Socket > connection: > public static void main(String[] args) { > Socket DNClient; > try { > DNClient = new Socket("127.0.0.1", 50010); > DataOutputStream os= new > DataOutputStream(DNClient.getOutputStream()); > os.writeBytes(""); > os.close(); > } catch (UnknownHostException e) { > // TODO Auto-generated catch block > e.printStackTrace(); > } catch (IOException e) { > // TODO Auto-generated catch block > e.printStackTrace(); > } > } -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org