Re: Perl

[Dan Shoop <shoop@xxxxxxxxxxx>]

At 12:39 PM -0400 05/09/02, CMS wrote:
> On 5/9/02 at 9:30 AM, anita@xxxxxxxxx (Anita Holmgren) wrote:
>
> >  Richard, mod_perl is not being used in WebTen.  mod_perl is included in
> iTools.
> >  WebTen supports Perl 5.004 and FastCGI, which operates somewhat like
> >  mod_perl in that it keeps the Perl program compiled and running in
> >  memory so that it is ready to respond quickly when a request comes in.
> >
> >  -Anita
>
> I was told from a perl guru, that Perl 5
> when beign access, by 5 people on the web, access the same script
> Perl would launch 5 interpretors of itself.

Yes this is true for any cgi, and for low volumes this isn't too much 
of an issue. For higher volumes, code for FastCGI, where the cgi 
application/script doesn't exit, but waits around for the next 
request.

But under unix, almost every task gets handled as a separate process, 
so this is hardy surprising.

> And mod_perl which shares the interpretor inside of Apache itself.
> is this not true ?

Ah, kinda. mod_perl bundles Perl inside of the apache executable, so 
it doesn't need launched separately but executes inside the same 
process.

Normally you launch a new httpd process for each request (to a 
point), which if calling an external cgi then forks another process, 
the cgi. With mod_perl you just save the fork and execute the perl 
script in the same process. And if the httpd doesn't get killed out, 
the script stays loaded and around for the next request.

> So, how does webten different from this ?

WebTen is apache. Not all apache's have mod_perl support enable. 
WebTen doesn't have mod_perl support included. As such you use perl 
as a cgi or fastcgi.

Remember, when coding for fastcgi or mod_perl you have to assume your 
code get's re-entered and need to watch your variable states 
carefully.

HTH

-dhan

------------------------------------------------------------------------
Dan Shoop                                       127 East Prospect Street
Consulting Internet Architect                   Waldwick, NJ 07463
shoop@xxxxxxxxxxx                               (201) 679-7329
                                                (707) 667-7866 (fax)

pgp public key available on the canonical key servers
pgp key fingerprint: FAC0 9434 B5A5 24A8 D0AF  12B1 7840 3BE7 3736 DE0B

"Sadly, text alone cannot convey the depths of my sarcasm."