if there is a data source at 47 the data source is stopped at 49 such that messages from the data source 25 are not delivered by its associated data process 26 to the subscribers 11 it will thus be understood that if a data source is not subscribed to by some minimum number or subscribers the data source is turned off so that its messages are not handled thus saving system resources fig3 is a data flow diagram for data source actions the data source action from a data source 25 of the fig1 starts at 50 the data source process 26 associated with the data source 25 having activity detects the new activity at 52 at 54 the data source process 26 delivers a message to the publish subscribe engine 12 to be delivered to a subscriber of that data source 25 having activity when the subscribed to data topic is active and has data available it will be understood that the message will be delivered from the data source process 26 only if it has not been stopped or turned off at 49 because its subscription match count is not above a designated threshold level at 41 as discussed in connection with fig2 at 56 the message from the data source process 26 if it has been turned on at 45 is delivered by the publish subscribe engine 12 is delivered to the subscriber or subscribers 11 who have subscribed to the data from the data source 25 having activity the data source action ends at 58 it will be understood that in the present system messages will not be transmitted through the system if the data to.