[Hadoop Wiki] Update of "SocketException" by SteveLoughran

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The "SocketException" page has been changed by SteveLoughran:
https://wiki.apache.org/hadoop/SocketException?action=diff&rev1=1&rev2=2

Comment:
Connection Reset

  = SocketException =
  
- Low level socket exceptions. Some diagnostics may be provided. 
+ Low level socket exceptions. Some diagnostics may be provided.
+ 
+ == Host is Down ==
  
  Example:
  
  {{{
- java.io.IOException: Failed on local exception: java.net.SocketException: Host is down; Host Details : local host is: "client1.example.org/192.168.1.86"; destination host is: "hdfs.example.org":8020; 
+ java.io.IOException: Failed on local exception: java.net.SocketException: Host is down; Host Details : local host is: "client1.example.org/192.168.1.86"; destination host is: "hdfs.example.org":8020;
  	at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:772)
  	at org.apache.hadoop.ipc.Client.call(Client.java:1472)
  	at org.apache.hadoop.ipc.Client.call(Client.java:1399)
@@ -34, +36 @@

   1. the destination host is "hdfs.example.org":8020  . This is the host to look for
   1. The exception is triggered by an HDFS call. (see {{{org.apache.hadoop.hdfs}}} at the bottom of the stack trace).
  
- That information is enough to hint to us that an HDFS operation is failing as the HDFS server "hdfs.example.org" is down. 
+ That information is enough to hint to us that an HDFS operation is failing as the HDFS server "hdfs.example.org" is down.
  
  It's not guaranteed to be the cause, as there could be other reasons, including configuration ones
   1. The URI to HDFS, as set in {{{core-site.xml}}} could be wrong; the client trying to talk to the wrong host —one that is down.
   1. The IP address of the host, as set in DNS or {{{/etc/hosts}}} is wrong. The client is trying to talk to a machine at the wrong IP address, a
  machine that the network stack thinks is down.
  
+ == Connection Reset ==
+ 
+ The connection was reset at the TCP layer
+ 
+ There is good coverage of this issue on [[StackOverflow|http://stackoverflow.com/questions/62929/java-net-socketexception-connection-reset]]
  
  Remember: These are [[YourNetworkYourProblem|your network configuration problems]] . Only you can fix them.