Package org.apache.hadoop.hdfs.server.namenode

Class ImageServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

org.apache.hadoop.hdfs.server.namenode.ImageServlet

All Implemented Interfaces:

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

@Private
public class ImageServlet
extends javax.servlet.http.HttpServlet

This class is used in Namesystem's jetty to retrieve/upload a file Typically used by the Secondary NameNode to retrieve image and edit file for periodic checkpointing in Non-HA deployments. Standby NameNode uses to upload checkpoints in HA deployments.

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static final String	CONTENT_DISPOSITION
static final String	HADOOP_IMAGE_EDITS_HEADER
static final String	PATH_SPEC
static final String	RECENT_IMAGE_CHECK_ENABLED
static final boolean	RECENT_IMAGE_CHECK_ENABLED_DEFAULT

Constructor Summary

Constructors

Constructor	Description
ImageServlet()

Method Summary

Modifier and Type	Method	Description
void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
protected void	doPut(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
static DataTransferThrottler	getThrottler(org.apache.hadoop.conf.Configuration conf)	Construct a throttler from conf
static DataTransferThrottler	getThrottlerForBootstrapStandby(org.apache.hadoop.conf.Configuration conf)
static void	setFileNameHeaders(javax.servlet.http.HttpServletResponse response, File file)
static void	setVerificationHeadersForGet(javax.servlet.http.HttpServletResponse response, File file)	Set headers for content length, and, if available, md5.

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPost, 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

Field Details

PATH_SPEC

public static final String PATH_SPEC

See Also:

• Constant Field Values

CONTENT_DISPOSITION

public static final String CONTENT_DISPOSITION

See Also:

• Constant Field Values

HADOOP_IMAGE_EDITS_HEADER

public static final String HADOOP_IMAGE_EDITS_HEADER

See Also:

• Constant Field Values

RECENT_IMAGE_CHECK_ENABLED

public static final String RECENT_IMAGE_CHECK_ENABLED

See Also:

• Constant Field Values

RECENT_IMAGE_CHECK_ENABLED_DEFAULT

public static final boolean RECENT_IMAGE_CHECK_ENABLED_DEFAULT

See Also:

• Constant Field Values

Constructor Details

ImageServlet

public ImageServlet()

Method Details

doGet

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

Overrides:

doGet in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

IOException

setFileNameHeaders

public static void setFileNameHeaders(javax.servlet.http.HttpServletResponse response,
 File file)

getThrottler

public static DataTransferThrottler getThrottler(org.apache.hadoop.conf.Configuration conf)

Construct a throttler from conf

Parameters:

conf - configuration

Returns:

a data transfer throttler

getThrottlerForBootstrapStandby

public static DataTransferThrottler getThrottlerForBootstrapStandby(org.apache.hadoop.conf.Configuration conf)

setVerificationHeadersForGet

public static void setVerificationHeadersForGet(javax.servlet.http.HttpServletResponse response,
 File file)
                                         throws IOException

Set headers for content length, and, if available, md5.

Throws:

IOException

doPut

protected void doPut(javax.servlet.http.HttpServletRequest request,
 javax.servlet.http.HttpServletResponse response)
              throws javax.servlet.ServletException,
IOException

Overrides:

doPut in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

IOException