The Drools execution server is a web application that allows us to execute rules remotely. The server is accessible through a REST-like interface (REST stands for Representational State Transfer—http://en.wikipedia.org/wiki/Representational_State_Transfer). Thanks to REST, we can build very lightweight clients that don't need any Drools libraries for rule execution (not even a JVM). To demonstrate this, we'll build a client using Ruby language.
Drools server can be found in the standard Drools binary distribution within the web application module
drools-server.war. The Drools web server application needs to be deployed to an application server and started. It uses multiple knowledge agents to cache
KnowledgeBase instances. ...