Rack::Cache quickly fills up entitystore with old content

[mperham]

We're using redis-rack-cache for our store. We found that our Redis install was quickly taking all available memory, even though our pages are Cache-Control: public, max-age=180.

What I discovered is that rack-cache.use_native_ttl is not documented and not enabled by default; the Redis driver sets the content with no expiration at all meaning Redis will keep it around forever.

1. Could you document this flag? I was going off of this page: http://rtomayko.github.com/rack-cache/configuration
2. Does it make sense to enable this flag by default so it doesn't happen to others?

[mperham]

It looks like MetaStore doesn't support native TTL at all so Redis will eventually fill up with cruft anyways.