Right now Redis cannot be clustered production-ready. I wish. As I stated in the Wiki, you'll have to pry Redis from my dead body, I am very happy with it, and for me its a true swiss army knife and I've used it as such.

Even though it doesn't have clustering - it's rock solid in production and I haven't experienced a drop in one of my Redis servers in around 3 years.

That being said, if you are building a system where reliability is an explicit requirement you can't take those risks.