caching database queries at midnight? - php

Question

I'm using Redis in combination with laravel to cache some heavy queries in my application like this:
return Cache::remember('projects.wip', $this->cacheDuration(), function () {
...
});
private function cacheDuration()
{
return Carbon::now()->endOfDay()->diffInSeconds(Carbon::now());
}
At this moment, the cache expires as midnight, but the first person that passes this method in the morning will be the unlucky one that has to execute the query, so i would like to cache all these queries at midnight again. Is there an easy solution to this? Or will i have to manually mimic http calls to the server at night?

Answer 1

A good approach to achieve what you're looking for is to use a scheduler that executes at midnight to warm the cache.
https://laravel.com/docs/5.4/scheduling
First, use php artisan to create the command:
php artisan make:command WarmCache
You should edit it so it looks something like this:
<?php
namespace App\Console\Commands;
use Illuminate\Console\Command;
class WarmCache extends Command
{
/**
* The name and signature of the console command.
*
* #var string
*/
protected $signature = 'warmcache';
/**
* The console command description.
*
* #var string
*/
protected $description = 'Warms Cache';
/**
* Create a new command instance.
*
* #return void
*/
public function __construct()
{
parent::__construct();
}
/**
* Execute the console command.
*
* #return mixed
*/
public function handle()
{
// >>>> INSERT YOUR CACHE CODE HERE <<<<
}
}
You should add the code that warms your cache in the handle() function, depending on what you're trying to cache you may not need to make a http request. However, you can always use something like curl or guzzle to query the page as a http request if you need to.
Then add this to app/Console/Kernel -> $commands:
protected $commands = [
// ...
\App\Console\Commands\WarmCache::class,
// ...
];
Also, add this to app/Console\Kernel schedule() function so that it executes at mignight:
$schedule->command('warmcache')->daily();
Finally, make sure you have set up the crontask that will execute the laravel scheduler:
* * * * * php /path/to/artisan schedule:run >> /dev/null 2>&1