TL;DR of this issue:

• Every Symfony component and bundle uses a centralized log service thanks to Monolog.
• I want the same idea applied to the Cache component.

There is a lot of work around the new Cache component lately. But in my opinion, we are not talking about "the big picture" and how to make Cache a centerpiece feature for Symfony. This is how I imagine the Cache component being used in Symfony apps:

Defining application caches

When defining one cache, Symfony names it default automatically (same behavior as "swiftmailer" mailers and "doctrine" managers)

# app/config/config.yml

# simple cache without arguments
cache:
    type: array

# equivalent to:
# cache:
#    default:
#        type: array

Complex caches can define arguments:

# app/config/config.yml
cache:
    type: doctrine
    em: my_custom_em_id

You can also define lots of different caches in a single app (in this case is mandatory to name one of them default):

# app/config/config.yml
cache:
    default:
        type: array
    db:
        type: doctrine
        em: my_custom_em_id

They are available in the application as cache.default and cache.db services.
The cache service is an alias for cache.default.

Configuring the application caches

Params such as default_lifetime and namespace are available for any cache type:

# app/config/config.yml
cache:
    type: array
    default_lifetime: 600
    namespace: 'ACME__'

Using caches in Symfony components

All Symfony components define a cache option. Its value can be:

1. A boolean, to enable or disable the cache. If true, the default cache is used:

# app/config/config.yml
framework:
    validation:
        cache: true
        enable_annotations: true
    serializer:
        cache: true
    property_path:
        cache: true

doctrine:
    orm:
        cache: true
# you can also set 'metadata_cache_driver', 'result_cache_driver' 
# and 'query_cache_driver' separately

1. You can also set the id of the cache:

# app/config/config.yml
framework:
    validation:
        cache: db
        enable_annotations: true
    serializer:
        cache: default
    property_path:
        cache: default

1. It's also possible to define an array of cache ids for complex services:

# app/config/config.yml
doctrine:
    orm:
        cache: [db, default]

This cache can also be used for third-party bundles:

# app/config/config.yml
liip_imagine:
    cache: true  # or false, or 'db', or ['db', 'default'], etc.

Thoughts? Comments? Other ideas?