Since the theme of this thread seems to be non-clojure alternatives, I'll point in the direction of InfluxData (formerly InfluxDB)'s new-ish Kapacitor project.
While I'm unconvinced their custom JavaScripty DSL (TICKscript) is actually preferable to Clojure or even can be read without careful, quite LISP-like indentation, it is pretty similar in basic functionality to Riemann and is definitely not-Clojure*