I am running my application on a group of unclustered tomcat servers. It serves restlet web-services. As per restful paradigm, each call is stateless.
In this environment, I want the application to periodically review the database for status changes and take action. Since one of the actions is to fire off an email, I want to ensure that I don't check the status of a particular record more than once per review period.
I know that messaging would help with this situation, but I don't understand exactly how. The periodic event can be generated by each instance of the application. Is there a way to debounce similar messages in a message queue? What tool works best for this problem?