How to monitor buckets operations

Hi ,
my application usually have 15000 + ops /second. last night due to issue with app server my clients were unable to connect and thought it was couchbase isuue , which was not actually. so here i want to monitor these ops closely and set an alert to watch this ops if it falls under 5000 ops/sec ( i want some kind of alert to setup like pager duty or any).
i would appreciate your input on this.