Commit c22b18ab authored by Ken Coar's avatar Ken Coar
Browse files

Update comments and add nph-script Q&A. (BTW, "connexion" is *not* 

	a typo!)


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@77960 13f79535-47bb-0310-9956-ffa450edef68
parent 0817aeb7

docs/manual/misc/FAQ.html

+61 −5
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@@ -8,7 +8,7 @@ 
<!--#include virtual="header.html" -->

<H1>Apache Server Frequently Asked Questions</H1>

<P>

$Revision: 1.32 $ ($Date: 1997/04/21 22:27:57 $)

$Revision: 1.33 $ ($Date: 1997/04/21 22:43:23 $)

</P>

<P>

If you are reading a text-only version of this FAQ, you may find numbers
@@ -21,10 +21,6 @@ do not appear, and are not needed, for the hypertext version. 
<!-- - can't bind to port 80					    -->

<!--   - permission denied					    -->

<!--   - address already in use					    -->

<!-- - "httpd: could not set socket option TCP_NODELAY"		    -->

<!--   not a problem if occasional; client disc before server	    -->

<!--   setsockopt						    -->

<!-- - disable Apache buffering of script output by using nph-	    -->

<!-- - access control based on DNS name really needs MAXIMUM_DNS    -->

<!--   and double-check that rDNS resolves to name expected	    -->

<!-- - mod_auth & passwd lines "user:pw:.*" - ++1st colon onward is -->
@@ -124,6 +120,9 @@ do not appear, and are not needed, for the hypertext version. 
   <LI><A HREF="#nodelay">Why am I getting &quot;<SAMP>httpd: could not

    set socket option TCP_NODELAY</SAMP>&quot; in my error log?</A>

   </LI>

   <LI><A HREF="#nph-scripts">How can I get my script's output without

    Apache buffering it?</A>

   </LI>

  </OL>

 </LI>

</UL>
@@ -926,6 +925,63 @@ do not appear, and are not needed, for the hypertext version. 
  </P>

  <HR>

 </LI>

 <LI><A NAME="nph-scripts">

      <STRONG>How can I get my script's output without Apache buffering

      it?</STRONG>

     </A>

  <P>

  In order to improve network performance, Apache buffers script output

  into relatively large chunks.  If you have a script that sends

  information in bursts (such as partial-done messages in a multi-commit

  database transaction, perhaps), the client will not necessarily get

  the output as the script is generating it.

  </P>

  <P>

  To avoid this, Apache recognises scripts whose names begin with

  &quot;<SAMP>nph-</SAMP>&quot; as <EM>non-parsed-header</EM> scripts.

  That is, Apache won't buffer their output, but connect it directly to

  the socket going back to the client.

  </P>

  <P>

  While this will probably do what you want, there <EM>are</EM> some

  disadvantages to it:

  </P>

  <UL>

   <LI><STRONG>YOU</STRONG> (the script) are responsible for generating

     <STRONG>ALL</STRONG> of the HTTP header, and no longer

     <EM>just</EM> the &quot;<SAMP>Content-type</SAMP>&quot; or

     &quot;<SAMP>Location</SAMP>&quot; headers

   </LI>

   <LI>Unless your script generates its output carefully, you will see a

    performance penalty as excessive numbers of packets go back and forth

   </LI>

  </UL>

  <P>

  As an example how you might handle the former (in a Perl script):

  </P>

  <CODE>

   <DL>

    <DD>if ($0 =~ m:/*nph-:) {

        <BR>

	&nbsp;&nbsp;&nbsp;&nbsp;

	$HTTP_headers&nbsp;=&nbsp;

	&quot;HTTP/1.1&nbsp;200&nbsp;OK\015\012&quot;;

        <BR>

	&nbsp;&nbsp;&nbsp;&nbsp;

	$HTTP_headers&nbsp;.=&nbsp;

	&quot;Connection:&nbsp;close\015\012&quot;;

        <BR>

	&nbsp;&nbsp;&nbsp;&nbsp;

	printf&nbsp;($HTTP_headers);

	<BR>

	};

    </DD>

   </DL>

  </CODE>

  <P>

  and then follow with your normal non-<SAMP>nph</SAMP> headers.

  </P>

 </LI>

</OL>

<HR>

 <!--#include virtual="footer.html" -->