Efficient Information Flow Control by Reducing Meaningless Messages in P2PPSO Systems

In topic-based publish/subscribe (PS) model, each peer process (peer) only receives an event message whose publication topics include some common topic with the subscription topics. In a P2PPSO (P2P (peer-to-peer) type of topic-based PS with Object concept) model, each peer exchanges objects by publishing and receiving event messages with no centralized coordinator. Here, objects are denoted by topics and event messages are characterized by topics of the objects carried by the event messages. Suppose an event message \(e_j\) published by a peer \(p_j\) carries objects on some topics into a target peer \(p_i\). Here, objects in the peer \(p_j\) illegally flow to the peer \(p_i\) if the peer \(p_i\) is not allowed to subscribe the topics. An object of a peer \(p_i\) is illegal, whose topics the peer \(p_i\) is not allowed to subscribe. In this paper, we newly propose an ETOBSCO (Efficient TOBSCO) protocol where meaningless event messages are not published to reduce the number of event messages exchanged among peers. In the evaluation, we show the fewer number of event messages are delivered but longer update delay time to update replicas is taken in the ETOBSCO protocol.