Laravel Cached Database Stickiness

Guarantee database stickiness over the same user's consecutive requests.

Requirements

• PHP: ^7.1
• Laravel: ^5.8 || ^6.0 || ^7.0

Installing

composer require mpyw/laravel-cached-database-stickiness

The default implementation is provided by ConnectionServiceProvider, however, package discovery is not available. Be careful that you MUST register it in config/app.php by yourself.

<?php

return [

    /* ... */

    'providers' => [

        /* ... */

        Mpyw\LaravelCachedDatabaseStickiness\ConnectionServiceProvider::class,

        /* ... */

    ],

    /* ... */
];

Then select the proper cache driver:

| Driver | Is eligible? | Description | |:---|:---:|:---| | redis | 😄 | Very fast, scalable and reliable driver | | memcached | 😄 | Alternative for Redis | | dynamodb | 😃 | It works but not so suitable for short-term caching | | apc | 😧 | It works unless PHP processes are running in multiple machines or containers | | file | 😧 | It works unless PHP processes are running in multiple machines or containers | | database | 🤮 | We'll get into a chicken-or-egg situation | | array | 🤮 | Just for testing |

Features

This library provides the following features.

• Make HTTP server to take over the database sticky state from the previous user's request within the last 5 seconds.
• Make queue worker into referring to master by default.
• Make queue worker into referring to slave by implementing ShouldAssumeFresh on your Queueable (jobs, listeners, notifications and mailables).

Diagrams

Default

Sticky

Sticky Cached

Advanced Usage

Customize Stickiness TTL

The default stickiness TTL is 5 seconds. You can configure this value to add stickiness_ttl directive to your config/database.php.

<?php

return [

    /* ... */

    'default' => env('DB_CONNECTION', 'mysql'),

    /*
    |--------------------------------------------------------------------------
    | Database Connections
    |--------------------------------------------------------------------------
    |
    | Here are each of the database connections setup for your application.
    | Of course, examples of configuring each database platform that is
    | supported by Laravel is shown below to make development simple.
    |
    |
    | All database work in Laravel is done through the PHP PDO facilities
    | so make sure you have the driver for your particular database of
    | choice installed on your machine before you begin development.
    |
    */

    'connections' => [

        /* ... */

        'mysql' => [
            'read' => env('DB_HOST_READONLY') ? [
                'host' => env('DB_HOST_READONLY'),
            ] : null,
            'write' => [],
            'sticky' => (bool)env('DB_HOST_READONLY'),
            'stickiness_ttl' => 3, // Set the stickiness TTL to 3 seconds
            'driver' => 'mysql',
            'host' => env('DB_HOST', '127.0.0.1'),
            'port' => env('DB_PORT', '3306'),
            'database' => env('DB_DATABASE', 'forge'),
            'username' => env('DB_USERNAME', 'forge'),
            'password' => env('DB_PASSWORD', ''),

            /* ... */
        ],

    ],
    
];

Customize Connection Implementation

You can configure Connection implementation.

• Make sure ConnectionServiceProvider to be removed from config/app.php.
• Extend Connection with DispatchesConnectionEvents trait by yourself.

<?php

namespace App\Providers;

use App\Database\MySqlConnection;
use Illuminate\Database\Connection;
use Illuminate\Support\ServiceProvider;

class DatabaseServiceProvider extends ServiceProvider
{
    public function register(): void
    {
        Connection::resolverFor('mysql', function (...$parameters) {
            return new MySqlConnection(...$parameters);
        });
    }
}

<?php

namespace App\Database;

use Illuminate\Database\Connection as BaseMySqlConnection;
use Mpyw\LaravelCachedDatabaseStickiness\DispatchesConnectionEvents;

class MySqlConnection extends BaseMySqlConnection
{
    use DispatchesConnectionEvents;
}

Customize Stickiness Source

You can register the StickinessResolverInterface implementation to change the source for stickiness determination.

<?php

namespace App\Providers;

use Illuminate\Support\ServiceProvider;
use Mpyw\LaravelCachedDatabaseStickiness\StickinessResolvers\AuthBasedResolver;
use Mpyw\LaravelCachedDatabaseStickiness\StickinessResolvers\StickinessResolverInterface;

class DatabaseServiceProvider extends ServiceProvider
{
    public function register(): void
    {
        $this->app->bind(StickinessResolverInterface::class, AuthBasedResolver::class);
    }
}

| | Source | Middleware | |:---:|:---:|:---:| | IpBasedResolver(Default)| Remote IP address | | | AuthBasedResolver | Authenticated User ID | Required |

You must add ResolveStickinessOnResolvedConnections middleware after Authenticate when you use AuthBasedResolver.

--- a/app/Http/Kernel.php
+++ b/app/Http/Kernel.php
 <?php
 
 namespace App\Http;
 
 use Illuminate\Foundation\Http\Kernel as HttpKernel;
 
 class Kernel extends HttpKernel
 {
     /* ... */
 
     /**
      * The application's route middleware groups.
      *
      * @var array
      */
     protected $middlewareGroups = [
         'web' => [
             \App\Http\Middleware\EncryptCookies::class,
             \Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class,
             \Illuminate\Session\Middleware\StartSession::class,
             // \Illuminate\Session\Middleware\AuthenticateSession::class,
             \Illuminate\View\Middleware\ShareErrorsFromSession::class,
             \App\Http\Middleware\VerifyCsrfToken::class,
             \Illuminate\Routing\Middleware\SubstituteBindings::class,
         ],
 
         'api' => [
             'throttle:60,1',
             \Illuminate\Routing\Middleware\SubstituteBindings::class,
         ],
+
+        'auth' => [
+            \App\Http\Middleware\Authenticate::class,
+            \Mpyw\LaravelCachedDatabaseStickiness\Http\Middleware\ResolveStickinessOnResolvedConnections::class,
+        ],
+
+        'auth.basic' => [
+            \Illuminate\Auth\Middleware\AuthenticateWithBasicAuth::class,
+            \Mpyw\LaravelCachedDatabaseStickiness\Http\Middleware\ResolveStickinessOnResolvedConnections::class,
+        ],
     ];
 
     /**
      * The application's route middleware.
      *
      * These middleware may be assigned to groups or used individually.
      *
      * @var array
      */
     protected $routeMiddleware = [
-        'auth' => \App\Http\Middleware\Authenticate::class,
-        'auth.basic' => \Illuminate\Auth\Middleware\AuthenticateWithBasicAuth::class,
         'bindings' => \Illuminate\Routing\Middleware\SubstituteBindings::class,
         'cache.headers' => \Illuminate\Http\Middleware\SetCacheHeaders::class,
         'can' => \Illuminate\Auth\Middleware\Authorize::class,
         'guest' => \App\Http\Middleware\RedirectIfAuthenticated::class,
         'password.confirm' => \Illuminate\Auth\Middleware\RequirePassword::class,
         'signed' => \Illuminate\Routing\Middleware\ValidateSignature::class,
         'throttle' => \Illuminate\Routing\Middleware\ThrottleRequests::class,
         'verified' => \Illuminate\Auth\Middleware\EnsureEmailIsVerified::class,
     ];
 
     /* ... */
 }

Customize Worker Behavior

You can register the JobInitializerInterface implementation to change workers' behavior.

<?php

namespace App\Providers;

use Illuminate\Support\ServiceProvider;
use Mpyw\LaravelCachedDatabaseStickiness\JobInitializers\AlwaysFreshInitializer;
use Mpyw\LaravelCachedDatabaseStickiness\JobInitializers\JobInitializerInterface;

class DatabaseServiceProvider extends ServiceProvider
{
    public function register(): void
    {
        $this->app->bind(JobInitializerInterface::class, AlwaysFreshInitializer::class);
    }
}

| | General Queueable | ShouldAssumeFresh Queueable | ShouldAssumeModified Queueable | |:---:|:---:|:---:|:---:| | AlwaysModifiedInitializer(Default)| Master | Slave | Master | | AlwaysFreshInitializer | Slave | Slave | Master |

Attention

Don't call Schema::defaultStringLength() in ServiceProvider::boot()

Problem

Assume that you have the following ServiceProvider.

<?php

namespace App\Providers;

use Illuminate\Support\Facades\Schema;
use Illuminate\Support\ServiceProvider;

class AppServiceProvider extends ServiceProvider
{
    /**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot()
    {
        Schema::defaultStringLength(191);
    }
}

If you run composer install or directly call php artisan pacakge:discover, it will unexpectedly use caches. It will trigger errors when we execute the command in the environment unreachable to the cache repository.

RedisException  : Operation timed out

Solution

Directly use Illuminate\Database\Schema\Builder. Don't call via Illuminate\Support\Facades\Schema Facade.

 <?php
 
 namespace App\Providers;

-use Illuminate\Support\Facades\Schema;
+use Illuminate\Database\Schema\Builder as SchemaBuilder;
 use Illuminate\Support\ServiceProvider;
 
 class AppServiceProvider extends ServiceProvider
 {
     /**
      * Bootstrap any application services.
      *
      * @return void
      */
     public function boot()
     {
-        Schema::defaultStringLength(191);
+        SchemaBuilder::defaultStringLength(191);
     }
 }