Redis and mysql database

Im currently using Redis in my webProject. But i would like to dump the redis into mysql, so if redis result are empty, get the result from mysql and store it to redis.

How would i proceed to do this? Should i do one or two?

After editing/inserting into Redis, do the same to mysql

redis -> dump to mysql -> get from mysql if empty.

if so, how would i do this? or any other suggestions on how i should do the mysql as a backup if redis result is empty?