NAME

Catalyst::Controller::LeakTracker - Inspect leaks found by Catalyst::Plugin::LeakTracker

SYNOPSIS

    # in MyApp.pm

        package MyApp;

        use Catalyst qw(
                LeakTracker
        );

        #### in SomeController.pm

        package MyApp::Controller::Leaks;
    use Moose;

    use parent qw(Catalyst::Controller::LeakTracker);

    sub index :Path :Args(0) {
        my ( $self, $c ) = @_;
        $c->forward("list_requests"); # redirect to request listing view
    }

DESCRIPTION

This controller uses Catalyst::Controller::LeakTracker to display leak info on a per request basis.

ACTIONS

list_requests

List the leaking requests this process has handled so far.

If the all parameter is set to a true value, then all requests (even non leaking ones) are listed.

request $request_id

Detail the leaks for a given request, and also dump the event log for that request.

object $request_id $event_id

Detail the object created in $event_id.

Displays a stack dump, a Devel::Cycle report, and a Data::Dumper output.

If the maxdepth param is set, $Data::Dumper::Maxdepth is set to that value.

make_leak [ $how_many ]

Artificially leak some objects, to make sure everything is working properly

CAVEATS

In forking environments each child will have its own leak tracking. To avoid confusion run your apps under the development server or temporarily configure fastcgi or whatever to only use one child process.

TODO

This is yucky example code. But it's useful. Patches welcome.

Template::Declare

Instead of yucky HTML strings

CSS

I can't do that well, I didn't bother trying

Nicer displays

    <pre> ... </pre>

Only goes so far...

The event log is in most dire need for this.

Filtering, etc

Of objects, requests, etc. Javascript or serverside, it doesn't matter.

JSON/YAML/XML feeds

Maybe it's useful for someone.

MINI-TUTORIAL

Why use LeakTracker?

You have a Catalyst application that is consuming more and more memory over time. You would like to find out what classes are involved and where you may have cyclic references.

How to use LeakTracker?

Once you've plugged LeakTracker into your Catalyst application (see "SYNOPSIS"), then you can easily get statistics via Catalyst::Controller::LeakTracker. Just create a new controller exclusively for reporting on the objects that are not being garbage collected. Here is how:

        package MyAss::Controller::Leaks;
        
        sub BEGIN {
                use Moose;
                extends 'Catalyst::Controller::LeakTracker';
        }
        
        # redirect leaks/ to the report about memory consumed by each request
        sub index : Path : Args(0) {
                my ( $self, $c ) = @_;
                $c->forward("list_requests");  
        }
        
        1
        

In effect, the controller above turns the URI $c.request.base/leaks into a report on the objects that still have references to them, and thus consuming memory.

How to Interpret the Results?

The results found at leaks/ are per request. The results include the Catalyst actions requested and how much memory each consumed. One can "drill-down" on the request ID and get a report of all objects that the request has left lingering about. It's tits, try it out for yourself.

When to Not Use LeakTracker?

In Production, because it adds a significant amount of overhead to your application.

SEE ALSO

Devel::Events, Catalyst::Plugin::LeakTracker, http://blog.jrock.us/articles/Plugging%20a%20leaky%20whale.pod, Devel::Size, Devel::Cycle

AUTHOR

Yuval Kogman <nothingmuch@woobling.org>

CONTRIBUTORS

Mateu X. Hunter <hunter@missoula.org>

Wallace Reis <wreis@cpan.org>

COPYRIGHT & LICENSE

        Copyright (c) Yuval Kogman. All rights reserved
        This program is free software; you can redistribute it and/or modify it
        under the terms of the MIT license or the same terms as Perl itself.

cpanm Catalyst::Controller::LeakTracker

perl -MCPAN -e shell
install Catalyst::Controller::LeakTracker