Apc_cache.plugin is a plugin that uses APC (Alternative PHP Cache) to cache forum data in-memory. This plugin is intended for high-traffic sites. Currently only topic view counters are cached and will be written to the DB in batches.
NOTE: It doesn't help to enable more than one caching plugin at a time. Only the first will be used.
PHP's APC module must be installed and working. This plugin is available with FUDforum 3.0.2 and later releases.
Enable the plugin from the forums Plugin Manager.
This plugin uses FUDforum's CACHEGET and CACHESET hooks.