org.apache.hadoop.dfs
Class FileDataServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          org.apache.hadoop.dfs.FileDataServlet

All Implemented Interfaces:

Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

public class FileDataServlet
extends javax.servlet.http.HttpServlet

Redirect queries about the hosted filesystem to an appropriate datanode.

See Also:

HftpFileSystem, Serialized Form

Constructor Summary

FileDataServlet()

Method Summary

void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Service a GET request as described below.
protected static DatanodeInfo	pickSrcDatanode(org.apache.hadoop.dfs.DFSFileInfo i, NameNode nn) Select a datanode to service this request.

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, init, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FileDataServlet

public FileDataServlet()

Method Detail

pickSrcDatanode

protected static DatanodeInfo pickSrcDatanode(org.apache.hadoop.dfs.DFSFileInfo i,
                                              NameNode nn)
                                       throws IOException

Select a datanode to service this request. Currently, this looks at no more than the first five blocks of a file, selecting a datanode randomly from the most represented.

Throws:

IOException

doGet

public void doGet(javax.servlet.http.HttpServletRequest request,
                  javax.servlet.http.HttpServletResponse response)
           throws javax.servlet.ServletException,
                  IOException

Service a GET request as described below. Request: GET http://<nn>:<port>/data[/<path>] HTTP/1.1

Overrides:

doGet in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

IOException