APXS is a Perl script that is created when you build the Apache web server from source. Chances are that if you are getting these errors and you obtained Apache as a binary distribution, that APXS is not configured correctly for your system. Your best bet is to get the Apache source from http://httpd.apache.org and build it yourself. Use the following for a basic build (read the Apache docs for other options):

Note: The above steps assume that you downloaded the Apache source and placed it in your /usr/local/src directory.

Integrating Apache with Application Servers

S.Prasanna,
sprasanna199@gmail.com

To make the extending httpd with shared DLL modules easier, you can use apxs.

Make sure you have configured $CFG_LDFLAGS_SHLIB within apxs to include the --shared directive and the path to the shared code DLL cyghttpd.dll.

After performing make install you will probably have the following lines within your apxs:

  # apxs
  [...]
  my $CFG_LD_SHLIB      = q(dllwrap --export-all --output-def libhttpd.def --implib libhttpd.a --driver-name gcc);          # substituted via Makefile.tmpl
  my $CFG_LDFLAGS_SHLIB = q(-g); # substituted via Makefile.tmpl 
  my $CFG_LIBS_SHLIB    = q();        # substituted via Makefile.tmpl 
  [...]

  # apxs
  [...]
  my $CFG_LD_SHLIB      = q(gcc);          # substituted via Makefile.tmpl
  my $CFG_LDFLAGS_SHLIB = q(-g --shared); # substituted via Makefile.tmpl 
  my $CFG_LIBS_SHLIB    = q(/path/to/cyghttpd.dll);        # substituted via Makefile.tmpl 
  [...]

Now you should be able to create a shared DLL module from a mod_foo.c source file with:

  $ apxs -c mod_foo.c -o mod_foo.dll

Apache is controlled by a series of configuration files: httpd.conf, access.conf. and srm.conf (there's actually also a mime.types file, but you have to deal with that only when you're adding or removing MIME types from your server, which shouldn't be too often). The files contain instructions, called directives, that tell Apache how to run. Several companies offer GUI-based Apache front-ends, but it's easier to edit the configuration files by hand.

Remember to make back-up copies of all your Apache configuration files, in case one of the changes you make while experimenting renders the Web server inoperable.

Also, remember that configuration changes you make don't take effect until you restart Apache. If you've configured Apache to run as an inetd server, then you don't need to worry about restarting, since inetd will do that for you.

Download the reference card

As with other open-source projects, Apache users share a wealth of information on the Web. Possibly the single most useful piece of Apache-related information--apart from the code itself, of course--is a two-page guide created by Andrew Ford.

Called the Apache Quick Reference Card, it's a PDF file (also available in PostScript) generated from a database of Apache directives. There are a lot of directives, and Ford's card gives you a handy reference to them.

While this may not seem like a tip on how to run Apache, it will make your Apache configuration go much smoother because you will have the directives in an easy-to-access format.

One quick note--we found that the PDF page was a bit larger than the printable area of our printer (an HP LaserJet 8000 N). So we set the Acrobat reader to scale-to-fit and the pages printed just fine.

http://articles.techrepublic.com.com/5100-22-5076696.html

If you want to build quickly and creatively, you need to set up an environment that encourages and facilitates that process. If you don’t have the following basics down, your team will be constantly battling annoying issues instead of getting on with building. You’ll need:

1. Good version control. I suggest Git.
2. An easy-to-use source and changeset browser. We use Codebase.
3. Solid server infrastructure. Why not build on Flexiscale, Grid-Service, Mosso or EC2 and let the big boys worry about uptime and server load?
4. A ‘one-click’ deployment system. This means that deploying the code from your repository should take just one click. If it’s any more complex than that, there is potential for complications and downtime. Capistrano is brilliant if you’re using Rails.
5. Printers, chalk boards and meeting space. People need the physical space to throw around ideas. We’ve painted an entire wall with blackboard paint so the team has room to sketch ideas.
6. Coffee, water, music and healthy snacks.

A HelloWorld Module

Apache:

1)build

gcc -fpic -DSHARED_MODULE -I/usr/include/apr-0 -I/usr/include/httpd -c  ./mod_helloworld.c

ld -Bshareable -o mod_helloworld.so mod_helloworld.o

2) install

cp ./mod_helloworld.so /usr/lib/httpd/modules/

chmod 755 /usr/lib/httpd/modules/mod_helloworld.so

vi  /etc/httpd/conf/httpd.conf

LoadModule helloworld_module modules/mod_helloworld.so
<Location /helloworld>
        SetHandler helloworld
</Location>

then 
apachectl restart

3) testing 
http://localhost/helloworld
you will see :
this is a sample paged developed by xxxx after numerious struglling!!!

for apache2 in ubuntu

gcc -fpic -DLINUX=2 -D_GNU_SOURCE -D_LARGEFILE64_SOURCE -D_REENTRANT  -DSHARED_MODULE -I/usr/include/apache2 -I/usr/include/apr-1.0 -pthread -c  mod_helloworld.c
ld -Bshareable -o mod_helloworld.so mod_helloworld.o
if you need to link additional library ld -Bshareable -o mod_helloworld.so mod_helloworld.o -L. -lmyutils

sudo cp ./mod_helloworld.so /usr/lib/apache2/modules
sudo chmod 644 /usr/lib/apache2/modules/mod_helloworld.so

then set up similar entries in /etc/apache2/
modules_available

like:
sudo cp ./status.load ./helloworld.load
sudo cp ./status.conf ./helloworld.conf

sudo vim   ./helloworld.load
LoadModule helloworld_module /usr/lib/apache2/modules/mod_helloworld.so

sudo vim   ./helloworld.conf
<IfModule mod_helloworld.c>
#
# Allow server status reports generated by mod_status,
# with the URL of http://servername/server-status
# Uncomment and change the ".example.com" to allow
# access from other hosts.
#
<Location /helloworld>
    SetHandler helloworld
#    Allow from .example.com
</Location>

</IfModule>


sudo ln -s ../mods-available/helloworld.conf ./helloworld.conf 
sudo ln -s ../mods-available/helloworld.load ./helloworld.load



sudo /usr/sbin/apache2ctl stop
sudo /usr/sbin/apache2ctl start

As I said the second and third steps are troublesome only when not done before. Here is an implementation for those steps that I’ve written as a part of (yet unreleased) CGI library for C++. It implements functions that take the care of the first three steps and return to the user an STL map containing the form elements’ names in the key and their value in the map pair’s value. This functions allows to process forms in a similar way to processing forms in PHP using $_GET and $_POST.

Here is a simple example of processing a “get” form using the above getpost.h header file.

Apache JServ Protocol Version 1.1 (AJPv1.1)

Standard - September 9, 1998

describes the protocol used to communicate between a web server module
and the Apache JServ servlet engine over a TCP socket.

Introduction

The authentication scheme used for AJPv1.0 (used by Apache JServ 0.9.xx) was considered too simple and worked only on local environments. For this reason, while the request/response phase of the protocol were kept unchanged, authentication handshake was ported from higher versions of the protocol (proposed as a future extension) and implemented here for security reasons.

This will also provide more feedback to developers for newer revisions of the AJP protocol.