Devel::NYTProf::Apache - Profile mod_perl applications with Devel::NYTProf

  # 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.

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.

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>

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>

Profiling mod_perl on Windows is not supported because NYTProf currently doesn't support threads.

Devel::NYTProf

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 (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.