Mozilla - HTTPLiveHeaders - Revision history

PeterHarding at 22:26, 4 March 2008

2008-03-04T22:26:42Z

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	Web development community.		Web development community.

	[[Category:Internet]][[Category:Development]]		[[Category:Mozilla]][[Category:Internet]][[Category:Development]]

PeterHarding at 01:28, 25 January 2008

2008-01-25T01:28:03Z

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	use the LiveHTTPHeaders tool? Share your experience and opinions with the		use the LiveHTTPHeaders tool? Share your experience and opinions with the
	Web development community.		Web development community.

			[[Category:Internet]][[Category:Development]]

PeterHarding at 03:17, 12 December 2007

2007-12-12T03:17:00Z

← Older revision		Revision as of 13:17, 12 December 2007
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	= Monitor Web site requests with ~~Mozillaâ€™s~~ LiveHTTPHeaders extension =		= Monitor Web site requests with Mozilla™s LiveHTTPHeaders extension =
	== Tony Patton, TechRepublic ==		== Tony Patton, TechRepublic ==

PeterHarding at 02:53, 12 December 2007

2007-12-12T02:53:48Z

← Older revision		Revision as of 12:53, 12 December 2007
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	The tool's interface has these four areas:		The tool's interface has these four areas:

	* Headers: Provides the details of the HTTP request and response		* Headers: Provides the details of the HTTP request and response headers. A Clear button lets you quickly clear the window for a new
	headers. A Clear button lets you quickly clear the window for a new		request. A Replay button allows you to perform the request again. A great feature is the ability to save HTTP header logs for later analysis or replay via the Save button. Headers is the main part of the tool.
	request. A Replay button allows you to perform the request again. A great		* Generator: Provides a list of the requests made like post and get. You can filter the results to include or exclude images, redirects, CSS, invalid, and skipped requests. A Help button provides plenty of information on its proper usage. A Save button allows you to save the data. The data from the Generator may be used to feed load test tools. The Generator tool is an extension of LiveHTTPHeaders.
	feature is the ability to save HTTP header logs for later analysis or		* Config: Allows you to set various configuration options, which includes specifying whether it is opened in a new tab or window. You may filter or exclude URLs from the data and use a style sheet for displaying the results.
	replay via the Save button. Headers is the main part of the tool.		* About: Provides product information including version and contributor details. Also, buttons link you to the product home page and allow you to easily check for updates.
	* Generator: Provides a list of the requests made like post and get. You
	can filter the results to include or exclude images, redirects, CSS,
	invalid, and skipped requests. A Help button provides plenty of
	information on its proper usage. A Save button allows you to save the
	data. The data from the Generator may be used to feed load test tools. The
	Generator tool is an extension of LiveHTTPHeaders.
	* Config: Allows you to set various configuration options, which
	includes specifying whether it is opened in a new tab or window. You may
	filter or exclude URLs from the data and use a style sheet for displaying
	the results.
	* About: Provides product information including version and contributor
	details. Also, buttons link you to the product home page and allow you to
	easily check for updates.

	A great feature of LiveHTTPHeaders is the ability to save HTTP header logs		A great feature of LiveHTTPHeaders is the ability to save HTTP header logs

PeterHarding: New page: = Monitor Web site requests with Mozillaâ€™s LiveHTTPHeaders extension = == Tony Patton, TechRepublic == A client recently rang me up to find out why their Web site suddenly disappea...

2007-12-12T02:52:39Z

New page: = Monitor Web site requests with Mozillaâ€™s LiveHTTPHeaders extension = == Tony Patton, TechRepublic == A client recently rang me up to find out why their Web site suddenly disappea...

New page

= Monitor Web site requests with Mozillaâ€™s LiveHTTPHeaders extension =
== Tony Patton, TechRepublic ==

A client recently rang me up to find out why their Web site suddenly
disappeared and another company's Web site appeared in its place.
Mozilla's LiveHTTPHeaders extension was invaluable as I traced the Web
site requests, ultimately providing the information I needed to solve the
problem. Learn more about the LiveHTTPHeaders extension, and get a quick
HTTP primer.

== HTTP primer ==

A Web browser and Web server communicate via Hypertext Transfer Protocol
(HTTP). The browser sends a request, and the server replies with a
response. I'll show you a simple HTTP conversation so you can get a better
idea of the process. First, I will view the TechRepublic.com site. A
request is made:

GET / HTTP/1.1
Host: www.techrepublic.com
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.4) Gecko/20070515 Firefox/2.0.0.4

This request uses HTTP 1.1 to request the TechRepublic.com host; the
Firefox 2.0 browser is used to make the request. The processing is
transferred to the server, which sends the following response to the
request for the TechRepublic.com site:

HTTP/1.x 301 Moved Permanently
Date: Tue, 04 Sep 2007 14:45:59 GMT
Server: Apache/2
Location: http://techrepublic.com.com/
Content-Length: 236
Keep-Alive: timeout=15, max=867
Connection: Keep-Alive
Content-Type: text/html; charset=iso-8859-1

This response from the Web server provides a lot of information. One of
the more important details is included in the first line of the response
via the status code, which tells you the status of the request. A status
code of 200 is the most common value returned -- it means that
everything is okay. My example returns 301 -- this value means the Web
site has been moved. The World Wide Web Consortium provides a
comprehensive list of valid status codes.

The fourth line of the response gives the new location of the requested
resource. The request includes more information that may be useful
depending on the scenario. Notice that the third line of the response
reveals the Web server being used (Apache). Since the site has moved to a
new location, the request is redirected to the new site
(techrepublic.com.com). The redirection generates a new HTTP request, as
the following snippet demonstrates:

GET / HTTP/1.1
Host: techrepublic.com.com

This request receives the following answer via another HTTP response
header:

HTTP/1.x 200 OK
Server: Apache

I have only included the first two lines of the response, but you can see
that the HTTP status code is 200 for the request, signaling the request
was successfully processed. While watching HTTP traffic, you will see
requests for all resources used on a page. This includes graphic files,
external style sheets, JavaScript libraries, Flash files, and so forth.

Now that you have an idea about the basics of HTTP, I'll explore the
LiveHTTPHeaders tool, which allows you to take a peek at HTTP requests and
responses.

== LiveHTTPHeaders ==

LiveHTTPHeaders (http://livehttpheaders.mozdev.org/) is a free Mozilla
extension that allows you to monitor HTTP traffic for Web requests; that
is, you can easily watch browser requests as they are sent and the
responses from the Web server. You are restricted to Mozilla-based
browsers such as Firefox when using the extension.

After you download LiveHTTPHeaders with your Mozilla browser and it is
installed, LiveHTTPHeaders is an option available in the Tools menu. You
may run it in its own browser tab or via its own window. I prefer running
it in its own window since it is easier to switch between the browser and
another window or line them up side-by-side.

The tool's interface has these four areas:

* Headers: Provides the details of the HTTP request and response
headers. A Clear button lets you quickly clear the window for a new
request. A Replay button allows you to perform the request again. A great
feature is the ability to save HTTP header logs for later analysis or
replay via the Save button. Headers is the main part of the tool.
* Generator: Provides a list of the requests made like post and get. You
can filter the results to include or exclude images, redirects, CSS,
invalid, and skipped requests. A Help button provides plenty of
information on its proper usage. A Save button allows you to save the
data. The data from the Generator may be used to feed load test tools. The
Generator tool is an extension of LiveHTTPHeaders.
* Config: Allows you to set various configuration options, which
includes specifying whether it is opened in a new tab or window. You may
filter or exclude URLs from the data and use a style sheet for displaying
the results.
* About: Provides product information including version and contributor
details. Also, buttons link you to the product home page and allow you to
easily check for updates.

A great feature of LiveHTTPHeaders is the ability to save HTTP header logs
for later analysis or replay. A help window assists in finding out the
correct options. When the tool is open, it generates data for any request
made via the browser. However, you may disable/enable the capture of data
via the Capture check box in both the Headers and Generator tabs.

Another interesting feature is the ability to modify requests. That is,
you can modify the various pieces of information of requests such as the
User-Agent string, language settings, or POST request data. This is a nice
feature when debugging application behavior.

To solve my client's problem of the disappearing Web site, I was able to
use LiveHTTPHeaders to trace an HTTP request for a Web site. The request
was redirected twice, resulting in the wrong site being loaded. The
problem was tracked down to a DNS change made the previous night by a
member of the networking team.

== Installing LiveHTTPHeaders with Firefox 2.0 ==

The latest version of LiveHTTPHeaders is designed to work with pre-2.0
versions of Firefox, so it will not install as-is with Firefox 2.0. You
can find a lot of information about installation workarounds online. I
followed the instructions on the OraTransplant site
(http://www.oratransplant.nl/2006/11/07/using-livehttpheaders-with-firefox-20/),
and the tool worked with my Firefox 2.0 installation.

== A useful tool ==

The LiveHTTPHeaders Mozilla extension is a useful tool for both Web
developers and administrators. It provides an easy way to monitor HTTP
activity and track down potential problems with Web requests. It is
another tool to keep handy when those problems appear that require
extensive analysis to resolve.

What tools do you use when tracking down Web application problems? Do you
use the LiveHTTPHeaders tool? Share your experience and opinions with the
Web development community.