Message distribution system and method

A message distribution method executed by a message distribution system that individually manages messages transmitted from a sending apparatus for each of topics in a relay apparatus and distributes the messages on the topics subscribed to by a receiving apparatus from the relay apparatus to the receiving apparatus,

• the message distribution system comprising:
• a topic editor apparatus that manages the topics,
• the method comprising:
• a first step in which the receiving apparatus transmits, to the topic editor apparatus, an integration request that requests to integrate the topics subscribed to by the receiving apparatus itself when the number of the topics subscribed to by the receiving apparatus itself is equal to or larger than a predetermined first threshold;
• a second step in which the topic editor apparatus instructs the relay apparatus to integrate the topics requested to be integrated by the received integration request, starts subscription to the topics requested to be integrated by the integration request, and transmits the received messages to the relay apparatus, while instructing the receiving apparatus that has transmitted the integration request to subscribe to an integrated topic in which the topics requested to be integrated by the integration request are integrated;
• and
• a third step in which the relay apparatus generates the integrated topic into which the specified topics are integrated according to an instruction from the topic editor apparatus, manages the messages on the topics constituting the integrated topic as messages on the integrated topic, and distributes the messages on the integrated message to the receiving apparatus that subscribes to the integrated topic.