Cache

Using cache is a great way of making your application run quicker. The Symfony cachecomponent is shipped with many adapters to different storages. Every adapter isdeveloped for high performance.

The following example shows a typical usage of the cache:

use Symfony\Contracts\Cache\ItemInterface;
 
// The callable will only be executed on a cache miss.
$value = $pool->get('my_cache_key', function (ItemInterface $item) {
    $item->expiresAfter(3600);
 
    // ... do some HTTP request or heavy computations
    $computedValue = 'foobar';
 
    return $computedValue;
});
 
echo $value; // 'foobar'
 
// ... and to remove the cache key
$pool->delete('my_cache_key');

Symfony supports the Cache Contracts, PSR-6/16 and Doctrine Cache interfaces.You can read more about these at the component documentation.

New in version 4.2: The cache contracts were introduced in Symfony 4.2.

Configuring Cache with FrameworkBundle

When configuring the cache component there are a few concepts you should knowof:

• Pool
• This is a service that you will interact with. Each pool will always haveits own namespace and cache items. There is never a conflict between pools.
• Adapter
• An adapter is a template that you use to create Pools.
• Provider
• A provider is a service that some adapters are using to connect to the storage.Redis and Memcached are example of such adapters. If a DSN is used as theprovider then a service is automatically created.There are two pools that are always enabled by default. They are cache.app andcache.system. The system cache is used for things like annotations, serializer,and validation. The cache.app can be used in your code. You can configure whichadapter (template) they use by using the app and system key like:

• YAML

# config/packages/cache.yaml
framework:
    cache:
        app: cache.adapter.filesystem
        system: cache.adapter.system

• XML

<!-- config/packages/cache.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:framework="http://symfony.com/schema/dic/symfony"
    xsi:schemaLocation="http://symfony.com/schema/dic/services
        https://symfony.com/schema/dic/services/services-1.0.xsd">
 
    <framework:config>
        <framework:cache app="cache.adapter.filesystem"
            system="cache.adapter.system"
        />
    </framework:config>
</container>

• PHP

// config/packages/cache.php
$container->loadFromExtension('framework', [
    'cache' => [
        'app' => 'cache.adapter.filesystem',
        'system' => 'cache.adapter.system',
    ],
]);

The Cache component comes with a series of adapters pre-configured:

• cache.adapter.apcu
• cache.adapter.array
• cache.adapter.doctrine
• cache.adapter.filesystem
• cache.adapter.memcached
• cache.adapter.pdo
• cache.adapter.psr6
• cache.adapter.redisSome of these adapters could be configured via shortcuts. Using these shortcutswill create pool with service id of cache.[type]

• YAML

# config/packages/cache.yaml
framework:
    cache:
        directory: '%kernel.cache_dir%/pools' # Only used with cache.adapter.filesystem
 
        # service: cache.doctrine
        default_doctrine_provider: 'app.doctrine_cache'
        # service: cache.psr6
        default_psr6_provider: 'app.my_psr6_service'
        # service: cache.redis
        default_redis_provider: 'redis://localhost'
        # service: cache.memcached
        default_memcached_provider: 'memcached://localhost'
        # service: cache.pdo
        default_pdo_provider: 'doctrine.dbal.default_connection'

• XML

<!-- config/packages/cache.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:framework="http://symfony.com/schema/dic/symfony"
    xsi:schemaLocation="http://symfony.com/schema/dic/services
        https://symfony.com/schema/dic/services/services-1.0.xsd">
 
    <framework:config>
        <!--
        default_doctrine_provider: Service: cache.doctrine
        default_psr6_provider: Service: cache.psr6
        default_redis_provider: Service: cache.redis
        default_memcached_provider: Service: cache.memcached
        default_pdo_provider: Service: cache.pdo
        -->
        <framework:cache directory="%kernel.cache_dir%/pools"
            default_doctrine_provider="app.doctrine_cache"
            default_psr6_provider="app.my_psr6_service"
            default_redis_provider="redis://localhost"
            default_memcached_provider="memcached://localhost"
            default_pdo_provider="doctrine.dbal.default_connection"
        />
    </framework:config>
</container>

• PHP

// config/packages/cache.php
$container->loadFromExtension('framework', [
    'cache' => [
        // Only used with cache.adapter.filesystem
        'directory' => '%kernel.cache_dir%/pools',
 
        // Service: cache.doctrine
        'default_doctrine_provider' => 'app.doctrine_cache',
        // Service: cache.psr6
        'default_psr6_provider' => 'app.my_psr6_service',
        // Service: cache.redis
        'default_redis_provider' => 'redis://localhost',
        // Service: cache.memcached
        'default_memcached_provider' => 'memcached://localhost',
        // Service: cache.pdo
        'default_pdo_provider' => 'doctrine.dbal.default_connection',
    ],
]);

Creating Custom (Namespaced) Pools

You can also create more customized pools:

• YAML

# config/packages/cache.yaml
framework:
    cache:
        default_memcached_provider: 'memcached://localhost'
 
        pools:
            # creates a "custom_thing.cache" service
            # autowireable via "CacheInterface $customThingCache"
            # uses the "app" cache configuration
            custom_thing.cache:
                adapter: cache.app
 
            # creates a "my_cache_pool" service
            # autowireable via "CacheInterface $myCachePool"
            my_cache_pool:
                adapter: cache.adapter.array
 
            # uses the default_memcached_provider from above
            acme.cache:
                adapter: cache.adapter.memcached
 
            # control adapter's configuration
            foobar.cache:
                adapter: cache.adapter.memcached
                provider: 'memcached://user:[email protected]'
 
            # uses the "foobar.cache" pool as its backend but controls
            # the lifetime and (like all pools) has a separate cache namespace
            short_cache:
                adapter: foobar.cache
                default_lifetime: 60

• XML

<!-- config/packages/cache.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:framework="http://symfony.com/schema/dic/symfony"
    xsi:schemaLocation="http://symfony.com/schema/dic/services
        https://symfony.com/schema/dic/services/services-1.0.xsd">
 
    <framework:config>
        <framework:cache default_memcached_provider="memcached://localhost">
            <framework:pool name="custom_thing.cache" adapter="cache.app"/>
            <framework:pool name="my_cache_pool" adapter="cache.adapter.array"/>
            <framework:pool name="acme.cache" adapter="cache.adapter.memcached"/>
            <framework:pool name="foobar.cache" adapter="cache.adapter.memcached" provider="memcached://user:[email protected]"/>
            <framework:pool name="short_cache" adapter="foobar.cache" default_lifetime="60"/>
        </framework:cache>
    </framework:config>
</container>

• PHP

// config/packages/cache.php
$container->loadFromExtension('framework', [
    'cache' => [
        'default_memcached_provider' => 'memcached://localhost',
        'pools' => [
            'custom_thing.cache' => [
                'adapter' => 'cache.app',
            ],
            'my_cache_pool' => [
                'adapter' => 'cache.adapter.array',
            ],
            'acme.cache' => [
                'adapter' => 'cache.adapter.memcached',
            ],
            'foobar.cache' => [
                'adapter' => 'cache.adapter.memcached',
                'provider' => 'memcached://user:[email protected]',
            ],
            'short_cache' => [
                'adapter' => 'foobar.cache',
                'default_lifetime' => 60,
            ],
        ],
    ],
]);

Each pool manages a set of independent cache keys: keys of different poolsnever collide, even if they share the same backend. This is achieved by prefixingkeys with a namespace that's generated by hashing the name of the pool, the nameof the compiled container class and a configurable seedthat defaults to the project directory.

Each custom pool becomes a service where the service id is the name of the pool(e.g. custom_thing.cache). An autowiring alias is also created for each poolusing the camel case version of its name - e.g. custom_thing.cache can beinjected automatically by naming the argument $customThingCache and type-hinting itwith either CacheInterface orPsr\Cache\CacheItemPoolInterface:

use Symfony\Contracts\Cache\CacheInterface;
 
// from a controller method
public function listProducts(CacheInterface $customThingCache)
{
    // ...
}
 
// in a service
public function __construct(CacheInterface $customThingCache)
{
    // ...
}

Custom Provider Options

Some providers have specific options that can be configured. TheRedisAdapter allows you tocreate providers with option timeout, retry_interval. etc. To use theseoptions with non-default values you need to create your own \Redis providerand use that when configuring the pool.

• YAML

# config/packages/cache.yaml
framework:
    cache:
        pools:
            cache.my_redis:
                adapter: cache.adapter.redis
                provider: app.my_custom_redis_provider
 
services:
    app.my_custom_redis_provider:
        class: \Redis
        factory: ['Symfony\Component\Cache\Adapter\RedisAdapter', 'createConnection']
        arguments:
            - 'redis://localhost'
            - { retry_interval: 2, timeout: 10 }

• XML

<!-- config/packages/cache.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:framework="http://symfony.com/schema/dic/symfony"
    xsi:schemaLocation="http://symfony.com/schema/dic/services
        https://symfony.com/schema/dic/services/services-1.0.xsd">
 
    <framework:config>
        <framework:cache>
            <framework:pool name="cache.my_redis" adapter="cache.adapter.redis" provider="app.my_custom_redis_provider"/>
        </framework:cache>
    </framework:config>
 
    <services>
        <service id="app.my_custom_redis_provider" class="\Redis">
            <argument>redis://localhost</argument>
            <argument type="collection">
                <argument key="retry_interval">2</argument>
                <argument key="timeout">10</argument>
            </argument>
        </service>
    </services>
</container>

• PHP

// config/packages/cache.php
$container->loadFromExtension('framework', [
    'cache' => [
        'pools' => [
            'cache.my_redis' => [
                'adapter' => 'cache.adapter.redis',
                'provider' => 'app.my_custom_redis_provider',
            ],
        ],
    ],
]);
 
$container->getDefinition('app.my_custom_redis_provider', \Redis::class)
    ->addArgument('redis://localhost')
    ->addArgument([
        'retry_interval' => 2,
        'timeout' => 10
    ]);

Creating a Cache Chain

Different cache adapters have different strengths and weaknesses. Some might be reallyquick but small and some may be able to contain a lot of data but are quite slow.To get the best of both worlds you may use a chain of adapters. The idea is tofirst look at the quick adapter and then move on to slower adapters. In the worstcase the value needs to be recalculated.

• YAML

# config/packages/cache.yaml
framework:
    cache:
        pools:
            my_cache_pool:
                adapter: cache.adapter.psr6
                provider: app.my_cache_chain_adapter
            cache.my_redis:
                adapter: cache.adapter.redis
                provider: 'redis://user:[email protected]'
            cache.apcu:
                adapter: cache.adapter.apcu
            cache.array:
                adapter: cache.adapter.array
 
 
services:
    app.my_cache_chain_adapter:
        class: Symfony\Component\Cache\Adapter\ChainAdapter
        arguments:
            - ['@cache.array', '@cache.apcu', '@cache.my_redis']
            - 31536000 # One year

• XML

<!-- config/packages/cache.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:framework="http://symfony.com/schema/dic/symfony"
    xsi:schemaLocation="http://symfony.com/schema/dic/services
        https://symfony.com/schema/dic/services/services-1.0.xsd">
 
    <framework:config>
        <framework:cache>
            <framework:pool name="my_cache_pool" adapter="cache.adapter.psr6" provider="app.my_cache_chain_adapter"/>
            <framework:pool name="cache.my_redis" adapter="cache.adapter.redis" provider="redis://user:[email protected]"/>
            <framework:pool name="cache.apcu" adapter="cache.adapter.apcu"/>
            <framework:pool name="cache.array" adapter="cache.adapter.array"/>
        </framework:cache>
    </framework:config>
 
    <services>
        <service id="app.my_cache_chain_adapter" class="Symfony\Component\Cache\Adapter\ChainAdapter">
            <argument type="collection">
                <argument type="service" value="cache.array"/>
                <argument type="service" value="cache.apcu"/>
                <argument type="service" value="cache.my_redis"/>
            </argument>
            <argument>31536000</argument>
        </service>
    </services>
</container>

• PHP

// config/packages/cache.php
$container->loadFromExtension('framework', [
    'cache' => [
        'pools' => [
            'my_cache_pool' => [
                'adapter' => 'cache.adapter.psr6',
                'provider' => 'app.my_cache_chain_adapter',
            ],
            'cache.my_redis' => [
                'adapter' => 'cache.adapter.redis',
                'provider' => 'redis://user:[email protected]',
            ],
            'cache.apcu' => [
                'adapter' => 'cache.adapter.apcu',
            ],
            'cache.array' => [
                'adapter' => 'cache.adapter.array',
            ],
        ],
    ],
]);
 
$container->getDefinition('app.my_cache_chain_adapter', \Symfony\Component\Cache\Adapter\ChainAdapter::class)
    ->addArgument([
        new Reference('cache.array'),
        new Reference('cache.apcu'),
        new Reference('cache.my_redis'),
    ])
    ->addArgument(31536000);

Note

In this configuration the my_cache_pool pool is using the cache.adapter.psr6adapter and the app.my_cache_chain_adapter service as a provider. That isbecause ChainAdapter does not support the cache.pool tag. So it is decoratedwith the ProxyAdapter.

Using Cache Tags

In applications with many cache keys it could be useful to organize the data storedto be able to invalidate the cache more efficient. One way to achieve that is touse cache tags. One or more tags could be added to the cache item. All items withthe same key could be invalidate with one function call:

use Symfony\Contracts\Cache\ItemInterface;
use Symfony\Contracts\Cache\TagAwareCacheInterface;
 
class SomeClass
{
    private $myCachePool;
 
    // using autowiring to inject the cache pool
    public function __construct(TagAwareCacheInterface $myCachePool)
    {
        $this->myCachePool = $myCachePool;
    }
 
    public function someMethod()
    {
        $value0 = $this->myCachePool->get('item_0', function (ItemInterface $item) {
            $item->tag(['foo', 'bar']);
 
            return 'debug';
        });
 
        $value1 = $this->myCachePool->get('item_1', function (ItemInterface $item) {
            $item->tag('foo');
 
            return 'debug';
        });
 
        // Remove all cache keys tagged with "bar"
        $this->myCachePool->invalidateTags(['bar']);
    }
}

The cache adapter needs to implement TagAwareCacheInterface`to enable this feature. This could be added by using the following configuration.

• YAML

# config/packages/cache.yaml
framework:
    cache:
        pools:
            my_cache_pool:
                adapter: cache.adapter.redis
                tags: true

• XML

<!-- config/packages/cache.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:framework="http://symfony.com/schema/dic/symfony"
    xsi:schemaLocation="http://symfony.com/schema/dic/services
        https://symfony.com/schema/dic/services/services-1.0.xsd">
 
    <framework:config>
        <framework:cache>
          <framework:pool name="my_cache_pool" adapter="cache.adapter.redis" tags="true"/>
        </framework:cache>
    </framework:config>
</container>

• PHP

// config/packages/cache.php
$container->loadFromExtension('framework', [
    'cache' => [
        'pools' => [
            'my_cache_pool' => [
                'adapter' => 'cache.adapter.redis',
                'tags' => true,
            ],
        ],
    ],
]);

Tags are stored in the same pool by default. This is good in most scenarios. Butsometimes it might be better to store the tags in a different pool. That could beachieved by specifying the adapter.

• YAML

# config/packages/cache.yaml
framework:
    cache:
        pools:
            my_cache_pool:
                adapter: cache.adapter.redis
                tags: tag_pool
            tag_pool:
                adapter: cache.adapter.apcu

• XML

<!-- config/packages/cache.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:framework="http://symfony.com/schema/dic/symfony"
    xsi:schemaLocation="http://symfony.com/schema/dic/services
        https://symfony.com/schema/dic/services/services-1.0.xsd">
 
    <framework:config>
        <framework:cache>
          <framework:pool name="my_cache_pool" adapter="cache.adapter.redis" tags="tag_pool"/>
          <framework:pool name="tag_pool" adapter="cache.adapter.apcu"/>
        </framework:cache>
    </framework:config>
</container>

• PHP

// config/packages/cache.php
$container->loadFromExtension('framework', [
    'cache' => [
        'pools' => [
            'my_cache_pool' => [
                'adapter' => 'cache.adapter.redis',
                'tags' => 'tag_pool',
            ],
            'tag_pool' => [
                'adapter' => 'cache.adapter.apcu',
            ],
        ],
    ],
]);

Note

The interface TagAwareCacheInterface isautowired to the cache.app service.

Clearing the Cache

To clear the cache you can use the bin/console cache:pool:clear [pool] command.That will remove all the entries from your storage and you will have to recalculateall values. You can also group your pools into "cache clearers". There are 3 cacheclearers by default:

• cache.global_clearer
• cache.system_clearer
• cache.app_clearerThe global clearer clears all the cache in every pool. The system cache cleareris used in the bin/console cache:clear command. The app clearer is the defaultclearer.

To see all available cache pools:

$ php bin/console cache:pool:list

New in version 4.3: The cache:pool:list command was introduced in Symfony 4.3.

Clear one pool:

$ php bin/console cache:pool:clear my_cache_pool

Clear all custom pools:

$ php bin/console cache:pool:clear cache.app_clearer

Clear all caches everywhere:

$ php bin/console cache:pool:clear cache.global_clearer