NAME¶
Devel::NYTProf::Apache - Profile mod_perl applications with Devel::NYTProf
SYNOPSIS¶
# in your Apache config file with mod_perl installed
PerlPassEnv NYTPROF
PerlModule Devel::NYTProf::Apache
If you're using virtual hosts with "PerlOptions" that include either
"+Parent" or "+Clone" then see "VIRTUAL HOSTS"
below.
DESCRIPTION¶
This module allows mod_perl applications to be profiled using
"Devel::NYTProf".
If the NYTPROF environment variable isn't set
at the time
Devel::NYTProf::Apache is loaded then Devel::NYTProf::Apache will issue
a warning and default it to:
file=/tmp/nytprof.$$.out
The file actually created by NTProf will also have the process id appended to it
because the "addpid" option is enabled by default.
See "ENVIRONMENT VARIABLES" in Devel::NYTProf for more details on the
settings effected by this environment variable. Try using
"PerlPassEnv" so you can set the NYTPROF environment variable
externally.
Each profiled mod_perl process will need to have terminated before you can
successfully read the profile data file. The simplest approach is to start the
httpd, make some requests (e.g., 100 of the same request), then stop it and
process the profile data.
Alternatively you could send a TERM signal to the httpd worker process to
terminate that one process. The parent httpd process will start up another one
for you ready for more profiling.
Example httpd.conf¶
It's often a good idea to use just one child process when profiling, which you
can do by setting the "MaxClients" to 1 in httpd.conf.
Using an "IfDefine" blocks lets you leave the profile configuration in
place and enable it whenever it's needed by adding "-D NYTPROF" to
the httpd startup command line.
<IfDefine NYTPROF>
MaxClients 1
PerlModule Devel::NYTProf::Apache
</IfDefine>
VIRTUAL HOSTS¶
If your httpd configuration includes virtual hosts with "PerlOptions"
that include either "+Parent" or "+Clone" then mod_perl2
will create a new perl interpreter to handle requests for that virtual host.
This causes some issues for profiling.
If "Devel::NYTProf::Apache" is loaded in the top-level configuration
then activity in any virtual hosts that use their own perl interpreter won't
be profiled. Normal virtual hosts will be profiled just fine.
You can profile a
single virtual host that uses its own perl interpreter
by loading "Devel::NYTProf::Apache"
inside the configuration for
that virtual host. In this case
do not use
"PerlModule" directive. You need to use a "Perl" directive
instead, like this:
<VirtualHost *:1234>
...
<Perl> use Devel::NYTProf::Apache; </Perl>
...
</VirtualHost>
LIMITATIONS¶
Profiling mod_perl on Windows is not supported because NYTProf currently doesn't
support threads.
SEE ALSO¶
Devel::NYTProf
AUTHOR¶
Adam Kaplan, "<akaplan at nytimes.com>"
Tim Bunce,
<
http://www.tim.bunce.name> and <
http://blog.timbunce.org>
Steve Peters, "<steve at fisharerojo.org>"
COPYRIGHT AND LICENSE¶
Copyright (C) 2008 by Adam Kaplan and The New York Times Company.
Copyright (C) 2008 by Steve Peters.
Copyright (C) 2008 by Tim Bunce.
This library is free software; you can redistribute it and/or modify it under
the same terms as Perl itself, either Perl version 5.8.8 or, at your option,
any later version of Perl 5 you may have available.