In formal terms, deciding... «Designing Data-Intensive Applications: The Big Ideas Behind Reliable, Scalable, and Maintainable Systems»

In formal terms, deciding on a total order of events is known as total order broadcast, which is equivalent to consensus. Most consensus algorithms are designed for situations in which the throughput of a single node is sufficient to process the entire stream of events, and these algorithms do not provide a mechanism for multiple nodes to share the work of ordering the events. It is still an open research problem to design consensus algorithms that can scale beyond the throughput of a single node and that work well in a geographically distributed setting.