Redis Cache By Xon 2.15.2

This add-on uses Credis with a custom cache provider for Redis. For best performance, install the PHP extension: phpredis

You must have a Redis instance installed, this is likely not possible with shared hosting

While XenForo 2 has a Redis connector, it requires phpredis. This add-on does not.

Feature Overview

• A pure php redis connector
• High availability support
• Exposes Redis cache object for use for use by other add-ons
• Implements some minor caching of forum thread counts
• Redirect XenForo's individual CSS template caching to hit Redis as otherwise it causes unexpected write & deadlocking on the xf_css_cache table

Installation
Edit src/config.php and add:

$config['cache']['enabled'] = true;
$config['cache']['sessions'] = true;
$config['cache']['provider'] = 'SV\RedisCache\Redis';
$config['cache']['config'] = [
    'server' => '127.0.0.1',
    'port' => 6379,
];

For details see the XenForo Manual: https://xenforo.com/docs/xf2/cache/

@eva2000 has also written an in-depth walkthrough around setting up redis and this add-on:
See "Xon's Redis Cache Addon For Xenforo 2.x" from:
https://community.centminmod.com/threads/xenforo-2-1-0-beta-1-install-2-1-0-final-upgrade-on-centmin-mod-123-09beta01-lemp-stack.16060/

Troubleshooting
Please be aware that Redis is very sensitive to latency in a virtual environment. If repeated connection failures or protocol errors are experienced disable any Redis Persistence options.

Options
By default, forum thread counts are cached. In general, this is observable when moving large number of threads from one forum to another, and the total page counts are wrong.

Redis Statistics
Admincp dash board is extended with basic redis statistics:

Debugger Statistics

Include redis timings when using the _debug=1 view for a page

Read Scaling

With the $config['cache']['config']['load_from_replica'] option, reads can be deferred to a singular replica instance. This takes all the options of 'config' (except the replicaconfig)

See the FAQ for configuration samples.

High availability

The Zend component support primary/replica setups with Redis Sentinel support. It does not support Redis multi-master clustering.

• Additionally, this add-on implement caching of thread counts in a forum.
• Redis Sentinel support for high-availability (see FAQ for details).