coar 97/04/21 15:43:25
Modified: htdocs/manual/misc FAQ.html
Log:
Update comments and add nph-script Q&A. (BTW, "connexion" is *not*
a typo!)
Revision Changes Path
1.33 +61 -5 apache/htdocs/manual/misc/FAQ.html
Index: FAQ.html
===================================================================
RCS file: /export/home/cvs/apache/htdocs/manual/misc/FAQ.html,v
retrieving revision 1.32
retrieving revision 1.33
diff -C3 -r1.32 -r1.33
*** FAQ.html 1997/04/21 22:27:57 1.32
--- FAQ.html 1997/04/21 22:43:23 1.33
***************
*** 8,14 ****
<!--#include virtual="header.html" -->
<H1>Apache Server Frequently Asked Questions</H1>
<P>
! $Revision: 1.32 $ ($Date: 1997/04/21 22:27:57 $)
</P>
<P>
If you are reading a text-only version of this FAQ, you may find numbers
--- 8,14 ----
<!--#include virtual="header.html" -->
<H1>Apache Server Frequently Asked Questions</H1>
<P>
! $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
***************
*** 21,30 ****
<!-- - 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 -->
--- 21,26 ----
***************
*** 124,129 ****
--- 120,128 ----
<LI><A HREF="#nodelay">Why am I getting "<SAMP>httpd: could not
set socket option TCP_NODELAY</SAMP>" 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>
***************
*** 925,930 ****
--- 924,986 ----
requests your server handles, and it's advisory only in any case.
</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
+ "<SAMP>nph-</SAMP>" 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 "<SAMP>Content-type</SAMP>" or
+ "<SAMP>Location</SAMP>" 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>
+
+ $HTTP_headers =
+ "HTTP/1.1 200 OK\015\012";
+ <BR>
+
+ $HTTP_headers .=
+ "Connection: close\015\012";
+ <BR>
+
+ printf ($HTTP_headers);
+ <BR>
+ };
+ </DD>
+ </DL>
+ </CODE>
+ <P>
+ and then follow with your normal non-<SAMP>nph</SAMP> headers.
+ </P>
</LI>
</OL>
<HR>
