of Nodejs, Cluster and messaging

I am attempting to build a nodejs clustered HTTP web server.

I am using cluster to fork the same number of workers as my desktop has cpu's. Each worker has its own unique key counter. for example worker 1 starts counting from 1000,000 worker 2 from 2000,000 etc.

at a random point in time i need all workers to reset there counters back to the starting value, e.g. worker 1 must reset to 1000,000, worker 2 must reset to 2000,000

i want to trigger thus reset operation by using a url endpoint parameter along the lines of

http://localhost:8888/aaaa/bbbb/cccc?resetCounter=true

The worker that receives this url request must send a message to the cluster master process, then the master process will broadcast to all the active workers instructing them to reset their particular counter.

how do you do this?