laravel-cache-evict

Efficiently remove expired cache data in Laravel.

Situation

As of writing, several Laravel cache drivers do not have automatic removal of expired cached items:

• file
• database

Why is it a problem?

Using any of the above cache drivers without regularly removing the expired items (aka "key eviction" in Redis) can result in storage overload, especially when you are creating a lot of temporary items with random keys.

The cache:clear command from Laravel works, but might not be the thing you want. It does not check item expiry (it removes everything), and also clears the Laravel framework cache (e.g. /bootstrap/cache/*), which can be especially problematic when you are using the file cache driver (consider a case: cache items are created by the www-data user but /bootstrap/cache/* is owned by the ubuntu user).

In this case, this library can help you remove only the expired items in your cache. See below sections for more details.

This library is designed to be memory efficient and (for database caches) non-blocking, so even if there are a lot of items in the cache (e.g. you are running this for the first time to deal with an oversized cache), it can still run reasonably well.

Install

via Composer:

composer require vectorial1024/laravel-cache-evict

Supported cache types

The following cache drivers from cache.php are currently supported:

• database
• file

Some drivers (e.g. memcached, redis) will never be supported because they have their own item eviction mechanisms; use those features instead of this library!

Custom eviction strategies can be defined for other cache drivers that does not have their own eviction mechanisms (see FAQ section).

Usage

You may run this in the command line:

# evicts the default cache in your Laravel app
php artisan cache:evict

# you may also specify the cache to clear; e.g. the file cache defined in cache.php:
php artisan cache:evict file

Or, you may put this into your console kernel schedule:

use Vectorial1024\LaravelCacheEvict\CacheEvictCommand;

// note: because this command may have long running time, it is strongly recommended to run this command in the background
// this avoids accidentally delaying other scheduled tasks

// evicts the default cache in your Laravel app
Schedule::command(CacheEvictCommand::class)->daily()->runInBackground();

// you may also specify the cache to clear; e.g. the file cache defined in cache.php:
Schedule::command(CacheEvictCommand::class, ['target' => 'file'])->daily()->runInBackground();

The relationship with cache.php

This library checks the cache name (not driver!) inside cache.php to determine which cache to clear. This means, if you have the following cache.php ...

[
    'stores' => [
        'local_store' => [
            'driver' => 'file',
            // other config...
        ],

        'another_store' => [
            'driver' => 'file',
            // other config...
        ],
    ],
]

... and you run the command like this ...

php artisan cache:evict local_store

... then, you will only evict the local_store cache. The another_store cache is unaffected by this command (assuming both are using separate directories, of course).

Testing

Using orchestra/testbench (customized PHPUnit) via Composer:

composer run-script test

Frequently-asked questions (FAQ)

How to define custom eviction strategies?

You can do so inside your Laravel service provider. Simply do the following:

public function boot()
{
    // register a handler for a specific cache driver
    // YourEvictStrategy extends Vectorial1024\LaravelCacheEvict\AbstractEvictStrategy
    CacheEvictStrategies::registerDriverStrategy('your_driver_name', YourEvictStrategy::class);

    // or, register that a specific cache driver should not be handled because it has its own handler already
    CacheEvictStrategies::registerDriverRefusedBecauseFeatureExists('self_managed_driver_name');
}

Will this library help me reclaim database disk spaces?

No, but if you are using this library regularly to evict expired items, then you do not need to worry about reclaiming free space. For more details, talk with a system admin/database specialist.