Devel::NYTProf::ApacheUser Contributed Perl DocumentaDevel::NYTProf::Apache(3)NAMEDevel::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.
perl v5.14.2 2012-03-22 Devel::NYTProf::Apache(3)
