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Tim Bunce > Plack-Middleware-Debug-CatalystPluginCache > Plack::Middleware::Debug::CatalystPluginCache



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Module Version: 0.101   Source  


Plack::Middleware::Debug::CatalystPluginCache - Panel for monitoring Catalyst::Plugin::Cache's


version 0.101


    enable "Debug:CatalystPluginCache";

is equivalent to:

    enable "Debug:CatalystPluginCache",
        app_class => '...', # Catalyst class name is determined automatically
        show_process_stats   => 1,
        show_global_stats    => 0,
        track_miss_locations => 0;



The default output consists of a summary of cache statistics, for each of the caches configured for Catalyst::Plugin::Cache, for the current request:

    Cache   Get   Miss  Hit%  Set Compute Remove  Backend
    default 11    10    9.09  11  0       0       Cache::Memcached::libmemcached=HASH(0xa682020)

This becomes more useful as more Catalyst::Plugin::Cache caches are configured for different uses. You can then see more fine-grained details of how effectively the different caches are being used.


If track_miss_locations is enabled then, for each cache that had one or more misses, a summary of the subroutine call paths that encountered the misses is displayed:

    Call paths for misses in the default cache:
    . Catalyst::Plugin::PageCache::Catalyst::Plugin::Cache::Curried::get@106 =>
    . . Catalyst::Plugin::Static::Simple::Catalyst::Plugin::PageCache::dispatch@76 =>
    . . . Catalyst::Engine::PSGI::Hello::dispatch@158 =>
    . . . . Catalyst::Engine::PSGI::(eval)@156 =>
    . . . . . Catalyst::Catalyst::Engine::PSGI::run@2386 =>
    . . . . . . . misses => 1

Some 'uninteresting' packages are filtered out to aid readability.


If show_process_stats is enabled then a summary of the cache statistics is shown, like "General" above, except the stats refer to the lifetime of the server process which handled the request. Typically only useful in development environments with a single Plack application server process.


If show_global_stats is enabled then the cache backend service is queried for global stats before and after the request is processed and the differences in counts are displayed. For example:

    Cache    Global stats changes during time of request
    default  bytes: +2, bytes_read: +65915, bytes_written: +1635, cmd_get: +11, cmd_set: +11,
             curr_items: +1, evictions: +1, get_hits: +1, get_misses: +10, total_connections: +2, total_items: +11

Currently only global stats fromCache::Memcached::libmemcached based caches are supported. Others could be added easily. Note that these backend cache server stats will obviously be affected by any other clients using the cache services. They are most useful in development environments with a dedicated backend cache server.


Plack::Middleware::Debug, Cache::Memcached::libmemcached

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