Cache drivers (file, Redis, Memcached) in Laravel - Mini Project: Build & Apply

Cache Drivers Setup in Laravel

📖 Scenario: You are building a Laravel application that needs to store temporary data efficiently. Laravel supports multiple cache drivers like file, Redis, and Memcached. You will configure and use these cache drivers step-by-step.

🎯 Goal: Set up Laravel cache drivers by creating the cache configuration, selecting a cache driver, and writing code to store and retrieve cached data using the chosen driver.

📋 What You'll Learn

Create a cache configuration array with file, Redis, and Memcached drivers

Set a variable to select the default cache driver

Write code to store a value in the cache using the selected driver

Write code to retrieve the cached value and complete the cache usage

💡 Why This Matters

🌍 Real World

Caching is used in web applications to speed up response times by storing frequently accessed data temporarily. Laravel supports multiple cache drivers to fit different needs and environments.

💼 Career

Understanding cache drivers and how to configure them is important for backend developers working with Laravel to optimize application performance and scalability.

1

Create cache configuration array

Create a PHP array called cacheConfig with keys 'file', 'redis', and 'memcached'. Each key should have a nested array with a 'driver' key set to the same string as the key name.

Laravel

# Your code here

Hint

Think of cacheConfig as a list of cache driver settings. Each driver has a name and a driver type.

2

Set default cache driver

Add a variable called defaultDriver and set it to the string 'redis' to select Redis as the default cache driver.

Laravel

 ['driver' => 'file'],
    'redis' => ['driver' => 'redis'],
    'memcached' => ['driver' => 'memcached'],
];

# Your code here

Hint

Set defaultDriver to the exact string 'redis' to pick Redis as the cache driver.

3

Store a value in cache using the selected driver

Write code to create a variable cacheStore that simulates storing the string 'Laravel Cache' with the key 'welcome_message' using the defaultDriver. Use an array to represent the cache storage with the driver as the first key and the cache key as the second key.

Laravel

 ['driver' => 'file'],
    'redis' => ['driver' => 'redis'],
    'memcached' => ['driver' => 'memcached'],
];

$defaultDriver = 'redis';

# Your code here

Hint

Use $cacheStore[$defaultDriver]['welcome_message'] = 'Laravel Cache'; style to store the value.

4

Retrieve the cached value and complete cache usage

Add a variable cachedValue that retrieves the value stored under 'welcome_message' from cacheStore using defaultDriver. Then add a comment // Cache setup complete to mark the end.

Laravel

 ['driver' => 'file'],
    'redis' => ['driver' => 'redis'],
    'memcached' => ['driver' => 'memcached'],
];

$defaultDriver = 'redis';

$cacheStore = [
    $defaultDriver => [
        'welcome_message' => 'Laravel Cache'
    ]
];

# Your code here

Hint

Retrieve the cached value by accessing $cacheStore[$defaultDriver]['welcome_message'].

Practice

1. Which Laravel cache driver stores cached data as files on the local server?

easy

A. memcached

B. file

C. redis

D. database

Solution

1. Step 1: Understand cache driver types in Laravel

   Laravel supports multiple cache drivers like file, redis, memcached, and database.

2. Step 2: Identify the driver that uses local files

   The 'file' driver stores cache data as files on the local server's disk.

3. Final Answer:

   file -> Option B

4. Quick Check:

   Local file storage = file [OK]

Hint: File driver means cache saved as local files [OK]

Common Mistakes:

• Confusing Redis or Memcached as file storage
• Thinking database driver stores files
• Assuming 'file' driver is remote cache

2. Which is the correct way to set Redis as the cache driver in Laravel's config/cache.php file?

easy

A. 'default' => 'redis',

B. 'driver' => 'redis',

C. 'cache_driver' => 'redis',

D. 'cache' => 'redis',

Solution

1. Step 1: Locate the cache driver setting in config/cache.php

   The main cache driver is set by the 'default' key in the config array.

2. Step 2: Confirm correct syntax for Redis driver

   Setting 'default' => 'redis' tells Laravel to use Redis as the cache driver.

3. Final Answer:

   'default' => 'redis' -> Option A

4. Quick Check:

   Default key sets cache driver = 'default' [OK]

Hint: Set 'default' key to driver name in config/cache.php [OK]

Common Mistakes:

• Using 'driver' instead of 'default' key
• Writing 'cache_driver' which is invalid
• Confusing config keys with environment variables

3. Given this Laravel code snippet using Redis cache driver:

Cache::put('user_1', 'Alice', 3600);
$name = Cache::get('user_1');

What will be the value of $name immediately after this code runs?

medium

A. "Alice"

B. null

C. "user_1"

D. 3600

Solution

1. Step 1: Understand Cache::put usage

   Cache::put stores the value 'Alice' with key 'user_1' for 3600 seconds (1 hour).

2. Step 2: Retrieve cached value with Cache::get

   Cache::get('user_1') returns the stored value 'Alice' if it exists and is not expired.

3. Final Answer:

   "Alice" -> Option A

4. Quick Check:

   Cache get returns stored value = "Alice" [OK]

Hint: Cache::get returns stored value if not expired [OK]

Common Mistakes:

• Expecting key name instead of value
• Confusing expiration time as returned value
• Assuming null because of Redis driver

4. What is wrong with this Laravel cache configuration snippet for Memcached in config/cache.php?

'memcached' => [
    'driver' => 'memcached',
    'servers' => [
        ['host' => '127.0.0.1', 'port' => 11211],
    ],
],

Why might this cause an error?

medium

A. Driver name should be 'memcache' not 'memcached'

B. Port number 11211 is incorrect for Memcached

C. Missing 'weight' key in the server array

D. Host IP must be 'localhost' not '127.0.0.1'

Solution

1. Step 1: Check Memcached server config requirements

   Laravel expects each Memcached server array to include 'host', 'port', and 'weight' keys.

2. Step 2: Identify missing 'weight' key

   The given config lacks the 'weight' key, which can cause errors when connecting to Memcached.

3. Final Answer:

   Missing 'weight' key in the server array -> Option C

4. Quick Check:

   Memcached servers need 'weight' key [OK]

Hint: Memcached server config must include 'weight' [OK]

Common Mistakes:

• Assuming port 11211 is wrong (it's default)
• Confusing driver name with 'memcache'
• Thinking host IP must be 'localhost'

5. You want to cache user profile data using Redis in Laravel, but only for 10 minutes. Which code snippet correctly sets this with expiration?

hard

A. Cache::put('profile_123', $profileData, 600);

B. Cache::put('profile_123', $profileData, now()->addSeconds(300));

C. Cache::put('profile_123', $profileData, 5);

D. Cache::put('profile_123', $profileData, now()->addMinutes(10));

Solution

1. Step 1: Understand Cache::put expiration parameter

   Laravel's Cache::put accepts expiration as an integer number of minutes, or a Carbon/DateTime instance.

2. Step 2: Use now()->addMinutes(10) for 10 minutes expiration

   Passing now()->addMinutes(10) sets expiration 10 minutes from current time correctly.

3. Step 3: Analyze other options

   A uses 600 (600 minutes = 10 hours), too long; C uses 5 minutes, too short; D uses now()->addSeconds(300) (5 minutes), too short.

4. Final Answer:

   Cache::put('profile_123', $profileData, now()->addMinutes(10)); -> Option D

5. Quick Check:

   Use now()->addMinutes(10) for 10 min cache [OK]

Hint: Use now()->addMinutes(10) for 10-minute cache expiration [OK]

Common Mistakes:

• Using 600 which is 600 minutes (10 hours)
• Using small integer 5 (5 minutes)
• Using addSeconds(300) which is 5 minutes