# services.yaml
services:
    _defaults:
        autowire: true 
        autoconfigure: true
    my_cache.chain:
        class: Symfony\Component\Cache\Adapter\ChainAdapter
        arguments:
            - [ '@cache.adapter.array', '@cache.adapter.filesystem' ]
        tags:
            - { name: cache.pool, namespace: 'my-custom-ns' }

# cache.yaml
framework:
    cache:
        pools:
            my_chain_pool:
                adapter: my_cache.chain