NAME
CGI::SpeedyCGI - Speed up CGI scripts by running them
persistently
SYNOPSIS
#!/usr/local/bin/speedy
### Your CGI Script Here
##
## Optionally, use the CGI::SpeedyCGI module for various things
##
# Create a SpeedyCGI object
use CGI::SpeedyCGI;
my $sp = CGI::SpeedyCGI->new;
# See if we are running under SpeedyCGI or not.
print "Running under speedy=", $sp->i_am_speedy ? 'yes' : 'no', "\n";
# Set up a shutdown handler
$sp->set_shutdown_handler(sub { do something here });
# Set/get some SpeedyCGI options
$sp->setopt('timeout', 30);
print "maxruns=", $sp->getopt('maxruns'), "\n";
DESCRIPTION
SpeedyCGI is a way to run CGI perl scripts persistently, which
usually makes them run much more quickly. Converting scripts to
use SpeedyCGI is in most cases as simple has changing the
interpreter line at the top of the script from
#!/usr/local/bin/perl
to
#!/usr/local/bin/speedy
After the script is initially run, instead of exiting, SpeedyCGI
keeps the perl interpreter running in memory. During subsequent
runs, this interpreter is used to handle new requests, instead
of starting a new perl interpreter for each execution.
SpeedyCGI conforms to the CGI specification, and does not work
inside the web server. A very fast cgi-bin (written in C) is
executed for each request. This fast cgi-bin then contacts the
persistent Perl process, which is usually already in memory, to
do the work and return the results.
Since all of these processes run outside the web server, they
can't cause problems for the web server itself. Also, each perl
program runs as its own Unix process, so one program can't
interfere with another. Command line options can also be used to
deal with programs that have memory leaks or other problems that
might keep them from otherwise running persistently.
OPTIONS
How to Set
SpeedyCGI options can be set in several ways:
Command Line
The speedy command line is the same as for regular perl,
with the exception that SpeedyCGI specific options can be
passed in after a "--".
For example:
#!/usr/local/bin/speedy -w -- -t300
at the top of your script will call SpeedyCGI with the perl
option "`-w'" and will pass the "`-t'" option to speedy,
telling it to exit if no new requests have been received
after 300 seconds.
Environment
Environment variables can be used to pass in options. This
can only be done before the initial execution (ie not from
within the script itself).
CGI::SpeedyCGI
The CGI::SpeedyCGI module provides a method, setopt, to set
options from within the perl script at runtime. There is
also a getopt method to retrieve the current options.
mod_speedycgi
If you are using the optional Apache module, SpeedyCGI
options can be set in the httpd.conf file.
Options Available
The following options are available:
TIMEOUT
Command Line : -tN
Environment : SPEEDY_TIMEOUT
CGI::SpeedyCGI : TIMEOUT
mod_speedycgi : SpeedyTimeout
Default Value : 3600 (one hour)
Description:
If no new requests have been received after N
seconds, exit the persistent perl interpreter.
Use 0 to indicate no timeout.
MAXRUNS
Command Line : -rN
Environment : SPEEDY_MAXRUNS
CGI::SpeedyCGI : MAXRUNS
mod_speedycgi : SpeedyMaxruns
Default Value : 0 (ie no max)
Description:
Once the perl interpreter has run N times, exit.
TMPBASE
Command Line : -Tstr
Environment : SPEEDY_TMPBASE
CGI::SpeedyCGI : n/a
mod_speedycgi : SpeedyTmpbase
Default Value : /tmp/speedy
Description:
Use the given prefix for creating temporary files.
This must be a filename prefix, not a directory name.
BUFSIZ_POST
Command Line : -bN
Environment : SPEEDY_BUFSIZ_POST
CGI::SpeedyCGI : n/a
mod_speedycgi : n/a
Default Value : 1024
Description:
Use N bytes for the buffer that sends data
to the CGI script.
BUFSIZ_GET
Command Line : -BN
Environment : SPEEDY_BUFSIZ_GET
CGI::SpeedyCGI : n/a
mod_speedycgi : n/a
Default Value : 8192
Description:
Use N bytes for the buffer that receives data
from the CGI script.
MAXBACKENDS
Command Line : -MN
Environment : SPEEDY_MAXBACKENDS
CGI::SpeedyCGI : n/a
mod_speedycgi : n/a
Default Value : 0
Description:
If non-zero limits the number of backend processes that
speedy will spawn at any given time. This is intended
to prevent thrashing in which a large perl library
will cause the system to slow down to the point where
there is an explosion of speedy processes when speedy
spawns backends to deal with incoming requests.
METHODS
The following methods are available in the CGI::SpeedyCGI
module.
new
Create a new CGI::SpeedyCGI object.
my $sp = CGI::SpeedyCGI->new;
set_shutdown_handler($function_ref)
Register a function that will be called right before the
perl interpreter exits. This is not at the end of each
request, it is when the perl interpreter decides to exit
completely (due to a timeout, maxruns, etc)
$sp->set_shutdown_handler(sub {$dbh->logout});
i_am_speedy
Returns a boolean telling whether this script is running
under SpeedyCGI or not. A CGI script can run under regular
perl, or under SpeedyCGI. This method allows the script to
tell which environment it is in.
$sp->i_am_speedy;
setopt($optname, $value)
Set one of the SpeedyCGI options given in the OPTIONS
section. Returns the previous value that the option had.
$optname is case-insensitive.
$sp->setopt('TIMEOUT', 300);
getopt($optname)
Return the current value of one of the SpeedyCGI options.
$optname is case-insensitive.
$sp->getopt('TIMEOUT');
INSTALLATION
SpeedyCGI has been tried with perl versions 5.004_04 and
5.005_02, and under Solaris 2.6, Redhat Linux 5.1, and FreeBSD
3.1. There may be problems wither other OSes or earlier versions
of Perl.
To install, do the following:
perl Makefile.PL
make
make test
make install
This will install a "speedy" binary in the same directory where
"perl" was installed. If you want to install the optional Apache
module, see the README in the apache directory.
BUGS
* Under heavy load we may run out of sockets (especially on
FreeBSD), since they hang around in a TIME_WAIT state after
closing. Might do better with fifos (named pipes).
Workaround on FreeBSD is to increase the "maxusers" value in
the kernel config file and compile/install a new kernel. The
default value of 32 is too low -- use 256 or more.
* On Solaris w/Netscape Enterprise 3.x, occasionally the CGI
front-end gets stuck in the poll() call in speedy.c.
* "make test" reportedly fails under sun4 sunos 4.1.4
* Release 1.6 reportedly runs very slow on Dec Alpha running Unix
4.0b and fails the intial_eof test. 1.5 runs OK.
TODO
* Need benchmarks of speedy vs mod_perl
* Pass file descriptors 0/1 to the Perl prog using I_SENDFD on
systems that support it (like Solaris). Avoids the overhead
of copying through the CGI front-end.
* Need to figure out whether speedyhandler still works/is useful,
and if so document how to use it.
* In start_perl, use a poll() timeout instead of an alarm to
implement the timeout while waiting for an accept. It's
cleaner than a signal.
* Need to allow more program control from perl via the
CGI::SpeedyCGI module. Should be able to have the perl prog
wait for a new connection, etc.
* Add option to check the amount of memory in use and exit when it
gets too high.
* Need tests for:
* getopt, setopt and i_am_speedy methods.
* multiple persistent perl processes
* mod_speedycgi
* Add option to have a single perl process handle multiple cgi-
bin's.
MAILING LIST
speedycgi@newlug.org. Subscribe by sending a message to
speedycgi-request@newlug.org with "subscribe" in the body.
Archive is at http://newlug.org/mailArchive/speedycgi
DOWNLOADING
SpeedyCGI can be retrieved from:
http://daemoninc.com/speedycgi
http://www.cpan.org/modules/by-authors/id/H/HO/HORROCKS/
AUTHOR
Sam Horrocks
Daemon Consulting Inc.
http://daemoninc.com
sam@daemoninc.com
COPYRIGHT
Copyright (c) 1999-2000 Daemon Consulting Inc. All rights
reserved. This program is free software; you can redistribute it
and/or modify it under the same terms as Perl itself.