In the advanced sugar configuration options, there is the ability to point "external cache" to redis or memcached. What is actually being redirected? This doesn't replace, or even seem to augment, the local file cache.
How is this intended to be handled when running in a horizontally scaling environment? Is the ./cache/ directory intended to be shared between every front end node, and if so, is it possible to actually put this into a store like redis or memcache - or to generally offload it entirely?
Or is it safe to have each web node maintain it's own local copy of the cache directory?
Our intended deployment leverages code-deploy on aws in autoscale groups behind ELBs. Right now we're trying to leverage EFS mounted to the ./cache/ dir on all web nodes, but the overhead of EFS transactions is egregious for this task.
Is there a better way to handle this?