The @PLUGIN@ plugin allows to synchronize the eviction of caches between two Gerrit instances sharing the same repositories and database.
The plugin needs to be installed in both instances and every time a cache eviction occurs in one of the instances, the other instance's cache is updated. This way, both caches are kept synchronized.
For this synchronization to work, http must be enabled in both instances and the plugin must be configured with valid credentials. For further information, refer to config documentation.