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:addpid=1:endatexit=1

       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" in your httpd.conf if you can set the NYTPROF environment variable
       externally.  Note that if you set the NYTPROF environment variable externally then the
       file name obviously can't include the parent process id. For example, to set stmts=0
       externally, use:

           NYTPROF=file=/tmp/nytprof.out:out:addpid=1:endatexit=1:stmts=0

       Each profiled mod_perl process will need to have terminated cleanly 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 usually a good idea to use just one child process when profiling, which you can do by
       setting the "MaxClients" to 1 in httpd.conf.

       Set "MaxRequestsPerChild" to 0 to avoid worker processes exiting and restarting during the
       profiling, which would split the profile data across multiple files.

       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
             MaxRequestsPerChild 0
             PerlModule Devel::NYTProf::Apache
         </IfDefine>

       With that configuration you should get two profile files, one for the parent process and
       one for the worker.

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.

TROUBLESHOOTING

       Truncated profile: Profiles for large applications can take a while to write to the disk.
       Allow sufficient time after stopping apache, or check the process has actually exited,
       before trying to read the profile.

       Truncated profile: The mod_perl child_terminate() function terminates the child without
       giving perl an opportunity to cleanup. Since "Devel::NYTProf::Apache" doesn't intercept
       the mod_perl child_terminate() function (yet) the profile will be corrupted if it's
       called. You're most likely to encounter this when using Apache::SizeLimit, so you may want
       to disable it while profiling.

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) 2008-2012 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.