I think you're slightly confused. There's no such thing as session caching. You can set up an alternate session driver in config.php and that's what you've done. Using redis.
The cache admin settings are for 'caching' (nothing to do with sessions) for which you are currently using Memcached. There's nothing in there that concerns sessions.
I'm not sure why you used both Redis and Memcached. Redis would happily do both.
The cache admin settings are for 'caching' (nothing to do with sessions) for which you are currently using Memcached. There's nothing in there that concerns sessions.
I'm not sure why you used both Redis and Memcached. Redis would happily do both.