NAME¶
SpeedyCGI - Speed up perl scripts by running them persistently.
SYNOPSIS¶
#!/usr/bin/speedy
### Your Script Here. For example:
print "Content-type: text/html\n\nHello World!\n";
##
## 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";
# Register a shutdown handler
$sp->add_shutdown_handler(sub { do something here });
# Register a cleanup handler
$sp->register_cleanup(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 perl scripts persistently, which can make them run
much more quickly. A script can be made to to run persistently by changing the
interpreter line at the top of the script from:
#!/usr/bin/perl
to
#!/usr/bin/speedy
After the script is initially run, instead of exiting, the perl interpreter is
kept running. During subsequent runs, this interpreter is used to handle new
executions instead of starting a new perl interpreter each time. A very fast
frontend program, written in C, is executed for each request. This fast
frontend then contacts the persistent Perl process, which is usually already
running, to do the work and return the results.
By default each perl script runs in its own Unix process, so one perl script
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.
SpeedyCGI can be used to speed up perl CGI scripts. It conforms to the CGI
specification, and does not run perl code inside the web server. Since the
perl interpreter runs outside the web server, it can't cause problems for the
web server itself.
SpeedyCGI also provides an Apache module so that under the Apache web server,
scripts can be run without the overhead of doing a fork/exec for each request.
With this module a small amount of frontend code is run within the web server
- the perl interpreters still run outside the server.
SpeedyCGI and PersistentPerl are currently both names for the same code.
SpeedyCGI was the original name, but because people weren't sure what it did,
the name PersistentPerl was picked as an alias. At some point SpeedyCGI will
be replaced by PersistentPerl, or become a sub-class of PersistentPerl to
avoid always having two distributions.
OPTIONS¶
Setting Option Values¶
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 the line:
#!/usr/bin/speedy -w -- -t300
at the top of your script will set the perl option
""-w"" and will pass the ""-t""
option to SpeedyCGI, setting the Timeout value to 300 seconds.
- Environment
- Environment variables can be used to pass in options. This
can only be done before the initial execution, not from within the script
itself. The name of the environment variable is always SPEEDY_ followed by
the option name in upper-case. For example to set the speedy Timeout
option, use the environment variable named SPEEDY_TIMEOUT.
- Module
- The CGI::SpeedyCGI module provides the setopt method to set
options from within the perl script at runtime. There is also a getopt
method to retrieve the current options. See "METHODS"
below.
- Apache
- If you are using the optional Apache module, SpeedyCGI
options can be set in the httpd.conf file. The name of the apache
directive will always be Speedy followed by the option name. For example
to set the Timeout option, use the apache directive SpeedyTimeout.
Note that these variables are global. There is currently no way to run
different scripts with different SpeedyCGI options when they are run from
the Apache module. Any <Directory> or <Location> contexts have
no effect on the scope of the SpeedyCGI options. When the same SpeedyCGI
option is set several times, the last one overrides the others.
Context¶
Not all options below are available in all contexts. The context for which each
option is valid is listed on the "Context" line in the section
below. There are three contexts:
- speedy
- The command-line "speedy" program, used normally
with #! at the top of your script or from a shell prompt.
- mod_speedycgi
- The optional Apache mod_speedycgi module.
- module
- During perl execution via the CGI::SpeedyCGI module's
getopt/setopt methods.
Options Available¶
- BackendProg
-
Command Line : -p<string>
Default Value : "/usr/bin/speedy_backend"
Context : mod_speedycgi, speedy
Description:
Path to the speedy backend program.
- BufsizGet
-
Command Line : -B<number>
Default Value : 131072
Context : speedy
Description:
Use <number> bytes as the maximum size for the buffer that
receives data from the perl backend.
- BufsizPost
-
Command Line : -b<number>
Default Value : 131072
Context : speedy
Description:
Use <number> bytes as the maximum size for the buffer that
sends data to the perl backend.
- Group
-
Command Line : -g<string>
Default Value : "none"
Context : mod_speedycgi, speedy
Description:
Allow a single perl interpreter to run multiple scripts.
All scripts that are run with the same group name and by
the same user will be run by the same group of perl
interpreters. If the group name is "none" then grouping is
disabled and each interpreter will run one script.
Different group names allow scripts to be separated into
different groups. Name is case-sensitive, and only the
first 12-characters are significant. Specifying an empty
group name is the same as specifying the group name
"default" - this allows just specifying "-g" on the command
line to turn on grouping.
- MaxBackends
-
Command Line : -M<number>
Default Value : 0 (no max)
Context : mod_speedycgi, speedy
Description:
If non-zero, limits the number of speedy backends running
for this perl script to <number>.
- MaxRuns
-
Command Line : -r<number>
Default Value : 500
Context : mod_speedycgi, module, speedy
Description:
Once the perl interpreter has run <number> times, re-exec
the backend process. Zero indicates no maximum. This
option is useful for processes that tend to consume
resources over time.
- PerlArgs
-
Command Line : N/A
Default Value : ""
Context : mod_speedycgi
Description:
Command-line options to pass to the perl interpreter.
- Timeout
-
Command Line : -t<number>
Default Value : 3600 (one hour)
Context : mod_speedycgi, module, speedy
Description:
If no new requests have been received after <number>
seconds, exit the persistent perl interpreter. Zero
indicates no timeout.
- TmpBase
-
Command Line : -T<string>
Default Value : "/tmp/speedy"
Context : mod_speedycgi, speedy
Description:
Use the given prefix for creating temporary files. This
must be a filename prefix, not a directory name.
- Version
-
Command Line : -v
Context : speedy
Description:
Print the SpeedyCGI version and exit.
METHODS¶
The following methods are available in the CGI::SpeedyCGI module.
- new
- Create a new CGI::SpeedyCGI object.
my $sp = CGI::SpeedyCGI->new;
- register_cleanup($function_ref)
- Register a function that will be called at the end of each
request, after your script finishes running, but before STDOUT and STDERR
are closed. Multiple functions can be added by calling the method more
than once. At the end of the request, each function will be called in the
order in which it was registered.
$sp->register_cleanup(\&cleanup_func);
- add_shutdown_handler($function_ref)
- Add a function to the list of functions 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 or reaching MaxRuns.
$sp->add_shutdown_handler(sub {$dbh->logout});
- set_shutdown_handler($function_ref)
- Deprecated. Similar to "add_shutdown_handler",
but only allows for a single function to be registered.
$sp->set_shutdown_handler(sub {$dbh->logout});
- i_am_speedy
- Returns a boolean telling whether this script is running
under SpeedyCGI or not. A perl 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;
To make your script as portable as possible, you can use the following test
to make sure both the SpeedyCGI module is available and you are running
under SpeedyCGI:
if (eval {require CGI::SpeedyCGI} && CGI::SpeedyCGI->i_am_speedy) {
Do something SpeedyCGI specific here...
To increase the speed of this check you can also test whether the following
variable is defined instead of going through the object interface:
$CGI::SpeedyCGI::i_am_speedy
- setopt($optname, $value)
- Set one of the SpeedyCGI options given in "Options
Available". Returns the option's previous value. $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');
- shutdown_now
- Shut down the perl interpreter right away. This function
does not return.
$sp->shutdown_now
- shutdown_next_time
- Shut down the perl interpreter as soon as this request is
done.
$sp->shutdown_next_time
INSTALLATION¶
To install SpeedyCGI you will need to either download a binary package for your
OS, or compile SpeedyCGI from source code. See "DOWNLOADING" for
information on where to obtain the source code and binaries.
Binary Installation¶
Once you have downloaded the binary package for your OS, you'll need to install
it using the normal package tools for your OS. The commands to do that are:
- Linux
-
rpm -i <filename>
- Solaris
-
gunzip <filename>.gz
pkgadd -d <filename>
- BSD
-
pkg_add <filename>
If you are also installing the apache module you will have to configure Apache
as documented in "Apache Configuration".
Source Code Installation¶
To compile SpeedyCGI you will need perl 5.005_03 or later, and a C compiler,
preferably the same one that your perl distribution was compiled with.
SpeedyCGI is known to work under Solaris, Redhat Linux, FreeBSD and OpenBSD.
There may be problems with other OSes or earlier versions of Perl. SpeedyCGI
may not work with threaded perl -- as of release 2.10, Linux and Solaris seem
to work OK with threaded perl, but FreeBSD does not.
Standard Install¶
To do a standard install from source code, execute the following:
perl Makefile.PL
make
make test
make install
This will install the speedy and speedy_backend binaries in the same directory
where perl was installed, and the SpeedyCGI.pm module in the standard perl lib
directory. It will also attempt to install the mod_speedycgi module if you
have the command
apxs in your path.
Install in a Different Directory¶
If you don't have permission to install into the standard perl directory, or if
you want to install elsewhere, the easiest way is to compile and install your
own copy of perl in another location, then use your new version of perl when
you run "perl Makefile.PL". The SpeedyCGI binaries and module will
then be installed in the same location as the new version of perl.
If you can't install your own perl, you can take the following steps:
- •
- Edit src/optdefs and change the default value for
BackendProg to the location where speedy_backend will be installed.
- •
- Compile as above, then manually copy the speedy and
speedy_backend binaries to where you want to install them.
- •
- If you want to use the CGI::SpeedyCGI module in your code
(it's not required), you will have to use "use lib" so it can be
located.
Setuid Install¶
SpeedyCGI has limited support for running setuid - installing this way may
compromise the security of your system. To install setuid do the following:
- •
- Run "perl Makefile.PL"
- •
- Edit speedy/Makefile and add "-DIAMSUID" to the
end of the "DEFINE = " line.
- •
- Run make
- •
- Take the resulting "speedy" binary and install it
suid-root as /usr/bin/speedy_suid
- •
- Change your setuid scripts to use /usr/bin/speedy_suid as
the interpreter.
This has been know to work in Linux and FreeBSD. Solaris will work as long as
the Group option is set to "none".
Apache Installation¶
To compile the optional apache mod_speedycgi module you must have the
apxs command in your path. Redhat includes this command with the
"apache-devel" RPM, though it may not work properly for
installation.
If the apache installation fails:
- •
- Copy the mod_speedycgi.so from the mod_speedycgi directory,
or from the mod_speedycgi2/.libs directory, to wherever your apache
modules are stored (try /usr/lib/apache)
- •
- Edit your httpd.conf (try
/etc/httpd/conf/httpd.conf) and add the following lines. The path
at the end of the LoadModule directive may be different in your
installation -- look at other LoadModules to see.
LoadModule speedycgi_module modules/mod_speedycgi.so
If you are using Apache-1, also add:
AddModule mod_speedycgi.c
Apache Configuration¶
Once mod_speedycgi is installed, it has to be configured to be used for your
perl scripts. There are two methods.
Warning! The instructions below may compromise the security of your web site.
The security risks associated with SpeedyCGI are similar to those of regular
CGI. If you don't understand the security implications of the changes below
then don't make them.
- 1. Path Configuration
- This is similar to the way /cgi-bin works -
everything under this path is handled by SpeedyCGI. Add the following
lines near the top of your httpd.conf - this will cause all scripts in
your cgi-bin directory to be handled by SpeedyCGI when they are accessed
as /speedy/script-name.
Alias /speedy/ /home/httpd/cgi-bin/
<Location /speedy>
SetHandler speedycgi-script
Options ExecCGI
allow from all
</Location>
- 2. File Extension Configuration
- This will make SpeedyCGI handle all files with a certain
extension, similar to the way .cgi files work. Add the following lines
near the top of your httpd.conf file - this will set up the file extension
".speedy" to be handled by SpeedyCGI.
AddHandler speedycgi-script .speedy
<Location />
Options ExecCGI
</Location>
FREQUENTLY ASKED QUESTIONS¶
- How does the speedy front end connect to the back end
process?
- Via a Unix socket in /tmp. A queue is kept in a
shared file in /tmp that holds an entry for each process. In that
queue are the pids of the perl processes waiting for connections. The
frontend pulls a process out of this queue, connects to its socket, sends
over the environment and argv, and then uses this socket for stdin/stdout
to the perl process.
- If another request comes in while SpeedyCGI script is
running, does the client have to wait or is another process started? Is
there a way to set a limit on how many processes get started?
- If another request comes while all the perl processes are
busy, then another perl process is started. Just like in regular perl
there is normally no limit on how many processes get started. But, the
processes are only started when the load is so high that they're
necessary. If the load goes down, the processes will die off due to
inactivity, unless you disable the timeout.
Starting in version 1.8.3 an option was added to limit the number of perl
backends running. See MaxBackends in "Options Available"
above.
- How much of perl's state is kept when speedy starts another
request? Do globals keep their values? Are destructors run after the
request?
- Globals keep their values. Nothing is destroyed after the
request. STDIN/STDOUT/STDERR are closed -- other files are not. %ENV and
@ARGV are the only globals changed between requests.
- How can I make sure speedy restarts when I edit a perl
library used by the CGI?
- Do a touch on the main cgi file that is executed. The mtime
on the main file is checked each time the front-end runs.
- Do I need to be root to install and/or run SpeedyCGI?
- No, root is not required.
- How can I determine if my perl app needs to be changed to
work with speedy? Or is there no modification necessary?
- You may have to make modifications.
Globals retain their values between runs, which can be good for keeping
persistent database handles for example, or bad if your code assumes
they're undefined.
Also, if you create global variables with "my", you shouldn't try
to reference those variables from within a subroutine - you should pass
them into the subroutine instead. Or better yet just declare global
variables with "use vars" instead of "my" to avoid the
problem altogether.
Here's a good explanation of the problem - it's for mod_perl, but the same
thing applies to speedycgi:
http://perl.apache.org/docs/general/perl_reference/perl_reference.html#my___Scoped_Variable_in_Nested_Subroutines
If all else fails you can disable persistence by setting MaxRuns to 1. The
only benefit of this over normal perl is that speedy will pre-compile your
script.
- How do I keep a persistent connection to a database?
- Since globals retain their values between runs, the best
way to do this is to store the connection in a global variable, then check
on each run to see if that variable is already defined.
For example, if your code has an "open_db_connection" subroutine
that returns a database connection handle, you can use the code below to
keep a persistent connection:
use vars qw($dbh);
unless (defined($dbh)) {
$dbh = &open_db_connection;
}
This code will store a persistent database connection handle in the global
variable "$dbh" and only initialize it the first time the code
is run. During subsequent runs, the existing connection is re-used.
You may also want to check the connection each time before using it, in case
it is not working for some reason. So, assuming you have a subroutine
named "db_connection_ok" that returns true if the db connection
is working, you can use code like this:
use vars qw($dbh);
unless (defined($dbh) && &db_connection_ok($dbh)) {
$dbh = &open_db_connection;
}
- Why do scripts with persistent Oracle database connections
hang?
- When using an IPC connection to Oracle, an oracle process
is fork'ed and exec'ed and keeps the stdout connection open, so that the
web server never gets an EOF. To fix the problem, either switch to using a
TCP connection to the database, or add the following perl code somewhere
before the DBI->connect statement:
use Fcntl;
fcntl(STDOUT, F_SETFD, FD_CLOEXEC);
This will set the close-on-exec flag on standard out so it is closed when
oracle is exec'ed.
USING GROUPS¶
The group feature in SpeedyCGI can be used to help reduce the amount of memory
used by the perl interpreters. By default groups are not used (group name is
"none"), and each perl script is given its own set of perl
interpreters. Each perl interpreter is also a separate system process.
When grouping is used, perl interpreters and perl scripts are put in a group.
All perl interpreters in a group can run perl scripts in the same group. What
this means is that by putting all your scripts into one group, there could be
one perl interpreter running all the perl scripts on your system. This can
greatly reduce your memory needs when running lots of different perl scripts.
SpeedyCGI group names are entities unto themselves. They are not associated with
Unix groups, or with the Group directive in Apache. Expect for the two special
group names "none" and "default", all group names are
created by the user of SpeedyCGI using the Group option described in
"OPTIONS"
If you want the maximum amount of grouping possible then you should run all
scripts with the group option set to "default". This the group name
used if you just specify "-g" on the command line without an
explicit group name. When you do this, you will get the fewest number of perl
interpreters possible - any perl interpreter will be able to run any of your
perl scripts.
Although using group "default" for all scripts results in the most
efficient use of resources, it's not always possible or desirable to do this.
You may want to use other group names for the following reasons:
- •
- To isolate misbehaving scripts, or scripts that don't work
in groups.
Some scripts won't work in groups. When perl scripts are grouped together
they are each given their own unique package name - they are not run out
of the "main" package as they normally would be. So, for
example, a script that explicitly uses "main" somewhere in its
code to find its subroutines or variables probably won't work in groups.
In this case, it's probably best to run such a script with group
"none", so it's compiled and run out of package main, and always
given its own interpreter.
In other cases, scripts may make changes to included packages, etc, that may
break other scripts running in the same interpreter. In this case such
scripts can be given their own group name (like "pariah") to
keep them away from scripts they are incompatible with. The rest of your
scripts can then run out of group "default". This will ensure
that the "pariah" scripts won't run within the same interpreter
as the other scripts.
- •
- To pass different perl or SpeedyCGI parameters to different
scripts.
You may want to use separate groups to create different policies for
different scripts.
For example, you may have an email application that contains ten perl
scripts, and since the common perl code used in this application has a bad
memory leak, you want to use a MaxRuns setting of 5 for all of these
scripts. You want to run all your other scripts with a normal MaxRuns
setting. To accomplish this you can edit the ten email application
scripts, and at the top use the line:
#!/usr/bin/speedy -- -gmail -r5
In the rest of your perl scripts you can use:
#!/usr/bin/speedy -- -g
What this will do is put the ten email scripts into a group of their own
(named "mail") and give them all the default MaxRuns value of 5.
All other scripts will be put into the group named "default",
and this group will have a normal MaxRuns setting.
DOWNLOADING¶
Binaries¶
Binaries for many OSes can be found at:
http://daemoninc.com/SpeedyCGI/download.html
Source Code¶
The standard source code distribution can be retrieved from any CPAN mirror or
from:
http://daemoninc.com/SpeedyCGI/download.html
http://www.cpan.org/modules/by-authors/id/H/HO/HORROCKS/
The latest development code can be obtained from the SourceForge CVS repository
using the following commands:
cvs -d:pserver:anonymous@cvs.SpeedyCGI.sourceforge.net:/cvsroot/speedycgi login
cvs -z3 -d:pserver:anonymous@cvs.SpeedyCGI.sourceforge.net:/cvsroot/speedycgi co 2.x
Press Enter when prompted for a password.
AUTHOR¶
Sam Horrocks
http://daemoninc.com
sam@daemoninc.com
Contributors¶
A lot of people have helped out with code, patches, ideas, resources, etc. I'm
sure I'm missing someone here - if so, please drop me an email.
- •
- Gunther Birznieks
- •
- Diana Eichert
- •
- Takanori Kawai
- •
- Robert Klep
- •
- Marc Lehmann
- •
- James McGregor
- •
- Josh Rabinowitz
- •
- Dave Parker
- •
- Craig Sanders
- •
- Joseph Wang
SEE ALSO¶
perl(1),
httpd(8),
apxs(8).
SpeedyCGI Home Page¶
http://daemoninc.com/SpeedyCGI/
Mailing List¶
- •
- SpeedyCGI users mailing list -
speedycgi-users@lists.sourceforge.net. Archives and subscription
information are at
http://lists.sourceforge.net/lists/listinfo/speedycgi-users
- •
- SpeedyCGI announcements mailing list -
speedycgi-announce@lists.sourceforge.net. Archives and subscription
information are at
http://lists.sourceforge.net/lists/listinfo/speedycgi-announce
Bugs and Todo List¶
Please report any bugs or requests for changes to the mailing list.
The current bugs / todo list can be found at
http://www.sourceforge.net/projects/speedycgi/. Go to the Bug Tracking menu
and select the group "bug" for bugs, or the group "rfe"
for the todo list.
Japanese Translation¶
http://member.nifty.ne.jp/hippo2000/perltips/CGI/SpeedyCGI.htm
Benchmarks¶
http://daemoninc.com/SpeedyCGI/benchmarks/
Success Stories¶
http://daemoninc.com/SpeedyCGI/success_stories/
Revision History¶
http://daemoninc.com/SpeedyCGI/CGI-SpeedyCGI/Changes
YAPC 2001 Presentation¶
I gave an Introduction to SpeedyCGI talk at YAPC 2001. It can be found at
http://daemoninc.com/SpeedyCGI/yapc_2001/
COPYRIGHT¶
Copyright (C) 2003 Sam Horrocks
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA.
This product includes software developed by the Apache Software Foundation
(
http://www.apache.org/).