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This is an excerpt from the latest version perlfaq3.pod, which
comes with the standard Perl distribution. These postings aim to
reduce the number of repeated questions as well as allow the community
to review and update the answers. The latest version of the complete
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3.19: How can I make my CGI script more efficient?

Beyond the normal measures described to make general Perl programs
faster or smaller, a CGI program has additional issues. It may be run
several times per second. Given that each time it runs it will need to
be re-compiled and will often allocate a megabyte or more of system
memory, this can be a killer. Compiling into C isn't going to help you
because the process start-up overhead is where the bottleneck is.

There are two popular ways to avoid this overhead. One solution involves
running the Apache HTTP server (available from )
with either of the mod_perl or mod_fastcgi plugin modules.

With mod_perl and the Apache::Registry module (distributed with
mod_perl), httpd will run with an embedded Perl interpreter which
pre-compiles your script and then executes it within the same address
space without forking. The Apache extension also gives Perl access to
the internal server API, so modules written in Perl can do just about
anything a module written in C can. For more on mod_perl, see

With the FCGI module (from CPAN) and the mod_fastcgi module (available
from ) each of your Perl programs becomes a
permanent CGI daemon process.

Both of these solutions can have far-reaching effects on your system and
on the way you write your CGI programs, so investigate them with care.



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