In general, we recommend MongoDB if you have a large community. Redis will work just fine, although the memory usage does scale up over time as everything is stored in-memory. Just something to consider.
How about back up data in ACP
I am using redis and the data is stored in dump.rdb. Everytime when I want to backup this file, I need to ssh to the server. Is it possible to achieve this in ACP? I think it is a good feature. Or, is it possible to send this file every other week to some Email address?
With cron you can automate pretty much anything you can write a script for. That includes sending files around.