A Wakeup Call for Internet Monitoring Systems: The Case for Distributed Triggers

There have been a number of recent proposals for distributed monitoring infrastructures. We argue that a vital missing component from these proposals is a distributed triggering mechanism, by which nodes in the system can proactively work together to maintain invariants and constraints over the system-wide behavior. Without such a triggering component, existing proposals are doomed to poor performance, high detection latency, or both. A key research challenge in building such a triggering mechanism lies in devising solutions whereby individual nodes can independently detect (and react to) violations of constraints that are defined in terms of the aggregate behavior of nodes in the system. We discuss our early efforts in designing such a triggering system and the research challenges that lie ahead.