|
Training, Open Source Programming Languages |
| Home | Accessibility | Courses | The Mouth | Resources | Site Map | About Us | Contact |
| For 2023 (and 2024 ...) - we are now fully retired from IT training. We have made many, many friends over 25 years of teaching about Python, Tcl, Perl, PHP, Lua, Java, C and C++ - and MySQL, Linux and Solaris/SunOS too. Our training notes are now very much out of date, but due to upward compatability most of our examples remain operational and even relevant ad you are welcome to make us if them "as seen" and at your own risk. Lisa and I (Graham) now live in what was our training centre in Melksham - happy to meet with former delegates here - but do check ahead before coming round. We are far from inactive - rather, enjoying the times that we are retired but still healthy enough in mind and body to be active! I am also active in many other area and still look after a lot of web sites - you can find an index ((here)) |
Redirecting failed proxy request to valid page
Web2 and caching example from a Well House Consultants training course
More on Web2 and caching [link]
More on Web2 and caching [link]
|
This example is described in the following article(s): • Handling failures / absences of your backend server nicely - [link] |
Source code: proxydown.php Module: H307
<?php
# Redirecting failed proxy request to valid page
/* If you have a proxy server that's occasionally unavailiable, you
might like to use a script like this rather than a regula error page
and you can then send out a cached page ... being in PHP, you can log
and count failures, and decide to start echoing hard errors if the
problem persists ... */
/* add a line such as:
ErrorDocument 503 "/proxydown.php"
into your httpd.conf or your .htaccess file ... and this script
is a sample proxydown.php */
# Send out code 200, even though this is the error 503 handler!
header("HTTP/1.1 200 OK");
$requested = $_SERVER["REQUEST_URI"];
$gotinstead = $_SERVER["PHP_SELF"];
# Sample log file record:
/* 192.168.200.199 - - [08/Feb/2013:17:42:17 +0000] "GET /dryfeet
HTTP/1.1" 20 0 189 "-" "Mozilla/5.0 (Macintosh; U; Intel Mac
OS X 10_6_4; en-us) AppleWe bKit/533.16 (KHTML, like Gecko)
Version/5.0 Safari/533.16" */
?>
<html>
<head>
<title>Unable to contact requested onward service</title>
</head>
<body>
<h1>Onward Service not available</h1>
You called for <?php print($requested); ?> but it is not available<br />
You got instead <?php print($gotinstead); ?><br />
</body>
</html>
# Redirecting failed proxy request to valid page
/* If you have a proxy server that's occasionally unavailiable, you
might like to use a script like this rather than a regula error page
and you can then send out a cached page ... being in PHP, you can log
and count failures, and decide to start echoing hard errors if the
problem persists ... */
/* add a line such as:
ErrorDocument 503 "/proxydown.php"
into your httpd.conf or your .htaccess file ... and this script
is a sample proxydown.php */
# Send out code 200, even though this is the error 503 handler!
header("HTTP/1.1 200 OK");
$requested = $_SERVER["REQUEST_URI"];
$gotinstead = $_SERVER["PHP_SELF"];
# Sample log file record:
/* 192.168.200.199 - - [08/Feb/2013:17:42:17 +0000] "GET /dryfeet
HTTP/1.1" 20 0 189 "-" "Mozilla/5.0 (Macintosh; U; Intel Mac
OS X 10_6_4; en-us) AppleWe bKit/533.16 (KHTML, like Gecko)
Version/5.0 Safari/533.16" */
?>
<html>
<head>
<title>Unable to contact requested onward service</title>
</head>
<body>
<h1>Onward Service not available</h1>
You called for <?php print($requested); ?> but it is not available<br />
You got instead <?php print($gotinstead); ?><br />
</body>
</html>
Learn about this subject
This module and example are covered on our public PHP Techniques course. If you have a group of
three or more trainees who need to learn the subject, we can also arrange a
private or on site course for you.
Books covering this topic
Yes. We have over 700 books in our library. Books
covering PHP are listed here and when you've selected a
relevant book we'll link you on to Amazon to order.
Other Examples
This example comes from our "Web2 and caching" training module. You'll find a description of the topic and some
other closely related examples on the "Web2 and caching" module index page.
Full description of the source code
You can learn more about this example on the training courses listed on this page,
on which you'll be given a full set of training notes.
Many other training modules are available for download (for limited use) from our download centre under an Open Training Notes License.
Many other training modules are available for download (for limited use) from our download centre under an Open Training Notes License.
Other resources
• Our Solutions centre provides a number of longer technical articles.
• Our Opentalk forum archive provides a question and answer centre.
• The Horse's mouth provides a daily tip or thought.
• Further resources are available via the resources centre.
• All of these resources can be searched through through our search engine
• And there's a global index here.
• Our Opentalk forum archive provides a question and answer centre.
• The Horse's mouth provides a daily tip or thought.
• Further resources are available via the resources centre.
• All of these resources can be searched through through our search engine
• And there's a global index here.
Web site author
Purpose of this website
This is a sample program, class demonstration or answer from a
training course. It's main purpose
is to provide an after-course service to customers who have attended our
public private or
on site courses, but the examples are made
generally available under conditions described below.
Conditions of use
Past attendees on our training courses are welcome to use individual
examples in the course of their programming, but must check
the examples they use to ensure that they are suitable for their
job. Remember that some of our examples show you how not to do
things - check in your notes. Well House Consultants take no responsibility
for the suitability of these example programs to customer's needs.
This program is copyright Well House Consultants Ltd. You are forbidden from using it for running your own training courses without our prior written permission. See our page on courseware provision for more details.
Any of our images within this code may NOT be reused on a public URL without our prior permission. For Bona Fide personal use, we will often grant you permission provided that you provide a link back. Commercial use on a website will incur a license fee for each image used - details on request.
This program is copyright Well House Consultants Ltd. You are forbidden from using it for running your own training courses without our prior written permission. See our page on courseware provision for more details.
Any of our images within this code may NOT be reused on a public URL without our prior permission. For Bona Fide personal use, we will often grant you permission provided that you provide a link back. Commercial use on a website will incur a license fee for each image used - details on request.
PH: 01144 1225 708225 • EMAIL: info@wellho.net • WEB: http://www.wellho.net • SKYPE: wellho
PAGE: http://www.wellho.info/resources/ex.php • PAGE BUILT: Sun Oct 11 14:50:09 2020 • BUILD SYSTEM: JelliaJamb