README

Overview

This package extends the standard Redis integration in Laravel, enabling it to work with Redis Sentinel while providing automatic failover handling and retry logic for transient errors.

It is based on the Namoshek/laravel-redis-sentinel package, with enhancements for retries and failover handling.

Features:

• Connects to Redis through Sentinel.
• Retries on connection failure and failover.
• Uses PhpRedis extension for Redis connections.
• Simple configuration with Laravel built-in Redis system.

Comparison with namoshek/laravel-redis-sentinel

Installation

Install the package via Composer:

composer require ignashevroman/laravel-redis-sentinel-retry

Configuration

In your config/database.php, add a new connection entry under the redis array, which uses the phpredis-sentinel client.

'redis' => [
    'client' => env('REDIS_CLIENT', 'phpredis-sentinel'),

    'default' => [
        'sentinel_host' => env('REDIS_SENTINEL_HOST', '127.0.0.1'),
        'sentinel_port' => (int) env('REDIS_SENTINEL_PORT', 26379),
        'sentinel_service' => env('REDIS_SENTINEL_SERVICE', 'mymaster'),
        'sentinel_timeout' => (float) env('REDIS_SENTINEL_TIMEOUT', 0),
        'sentinel_persistent' => env('REDIS_SENTINEL_PERSISTENT'),
        'sentinel_retry_interval' => (int) env('REDIS_SENTINEL_RETRY_INTERVAL', 0),
        'sentinel_read_timeout' => (float) env('REDIS_SENTINEL_READ_TIMEOUT', 0),
        'sentinel_username' => env('REDIS_SENTINEL_USERNAME'),
        'sentinel_password' => env('REDIS_SENTINEL_PASSWORD'),
        'password' => env('REDIS_PASSWORD'),
        'database' => (int) env('REDIS_DB', 0),
        
        // Additional options for retry functionality
        'sentinel_max_retries' => env('REDIS_SENTINEL_MAX_RETRIES', 3),
        'sentinel_retry_delay' => env('REDIS_SENTINEL_RETRY_DELAY', 100_000),
    ]
],

Note: The configuration options are the same as in namoshek/laravel-redis-sentinel, with two additional options for retry functionality:

• sentinel_max_retries: The number of retry attempts for Redis operations (default: 3).
• sentinel_retry_delay: The delay between retries in microseconds (default: 100,000).

Differences in Implementation:

1. Retry Logic (Retries)

   • This implementation introduces retry logic to handle transient errors such as temporary connection failures or readonly states. This allows automatic retries of requests if Redis becomes operational again after a failure.
   • In the case of an error like "READONLY" or a connection loss, the client will automatically retry the connection multiple times, improving the system's resilience.

2. Integration with Redis Sentinel:

   • This implementation enhances the automatic failover mechanism with Redis Sentinel. When the primary Redis server fails, the system automatically switches to a new master, if possible.
   • The new master is selected via Redis Sentinel, and if the current client loses connection or becomes "readonly", it tries to reconnect to the new master, taking into account settings for retry attempts and delays.

3. Configuration Parameters:

   • Two new configuration parameters were added to this package:
     • sentinel_max_retries — the maximum number of reconnection attempts.
     • sentinel_retry_delay — the delay between reconnection attempts.
   • These parameters provide flexibility in configuring the number of retries and delays for reconnection in case of failures.

4. RedisWrapper Reconnection Logic:

   • The RedisWrapper class manages the Redis client and encapsulates the retry logic, error checking, and failover handling.
   • If the connection is lost or becomes readonly, RedisWrapper automatically retries the connection for a set number of attempts, improving Redis availability.

5. Error Handling in RedisWrapper:

   • When an error occurs, such as a lost connection or readonly error, RedisWrapper attempts to reconnect through handleFailover (a method that manages reconnection).
   • If Redis does not recover after several attempts, an exception is thrown, just like in a standard Redis error scenario.

In general, this implementation focuses on improving fault tolerance and automating Redis connection management with Redis Sentinel, along with additional settings for controlling retry attempts and delay between reconnections.

License

This package is licensed under the MIT License. See the LICENSE file for more information.

Acknowledgments

A special thanks to the Namoshek team for their excellent work on the original laravel-redis-sentinel package, which served as the foundation for this package. This package extends their work by adding automatic retry functionality for Redis operations during failover scenarios.