data flow throughout the cluster a rule includes an action and a condition including an arbitrarily complex boolean expression actions are concrete tasks that can be invoked in response to a rule activation similar to the data model these actions are advertised and described at runtime an action includes a scope name and arguments the scope provides loose contextual information about the context in which the action will execute additional details on the action and the associated condition in a rule are described in reference to fig2 when a rule is activated the rule processing module 114 fulfills the actions argument and scope requirements through inference driven by each data item referenced and matched in the rule the rule processing module 114 or another component of the distributed database system 102 can compile a rule a form that facilitates rapid parallel execution the rule processing module 114 subscribes to relevant global and local data for its assigned domain the rule processing module 114 infers contextual connections between data items by following paths of commonality of the scope metadata the paths are described in additional details in reference to fig2 the rule processing module 114 evaluates rules in parallel against the totality of subscribed data the rule processing module 114 then invokes actions of activated rules an instantiation of a rule processing module executes on every node including the nodes 104.