[chef] How to coordinate restart across roles

[David Montgomery < >]

Hi,

I have three three roles, rabbit, worker servers, django servers.

If I want to restart the django servers I need to restart rabbit first, then the work servers and then django servers.

Off of the top of my head, I am thinkg about zookeep for co coordinating where each server is listing for a signal to restart.

How would I use chef and hosted chef for this co-ordination?  So

1) A signal is sent to the rabbit roles to restart.  It then sends this signal to the worker roles to restart then send a signal for the django servers t restart.

Since I have never done this before...I have no clue on how to proceed with chef.  Or is using a service like zookeeper best practice.

Thanks