Zend Redis Cache 1.6.0

This add-on packages Cm_Cache_Backend_Redis and Credis with a little glue-code to provide a Zend Cache for Redis. For best performance, install the php extension: phpredis

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.

Read Scaling

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

See the FAQ for configuration samples.

High availability

The Zend component support master/slave 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).
• Optionally, pipelining or loading from a slave can be enabled in XenForo_Model_DataRegistry::getMulti by adding the following lines to config.php. Preferably after setting up the cache.

require(XenForo_Application::getInstance()->getConfigDir().'/SV/RedisCache/Installer.php');

• Loading from a slave (limited opt-in support) is only enabled fro public (ie non-admin) pages.
  • APCu or /tmp/local_ips is used to store the list of local IPs fetched via shell_exec for "hostname --all-ip-addresses". If someone knows of a better way of getting all machine IPs, please tell me.
  • Note; APCu isn't recommended.

Zend Cache Tags Support

By default the Zend Cache "tags" support is disabled as XenForo does not use it and it introduces additional operations to support it. To enable;

$config['cache']['backendOptions']['enable_tags'] = true;

Licencing

Components licenced under; New BSD

• Cm_Cache_Backend_Redis
• Credis

Components licenced under; MIT Licence

• XenForo Add-on code

Installation

I recommend using Add-on install & upgrade to install this add-on.