Mohamad-Jaafar Nehme - Total Order Broadcast for Multi-Data Center Environments

Many uniform total order broadcast protocols have been designed in the last 30 years. They can be classified into two categories: those targeting low latency, and those targeting high throughput. Latency measures the time required to complete a single message broadcast without contention, whereas throughput measures the number of broadcasts that the processes can complete per time unit when there is contention. All the protocols that have been designed so far make the assumption that the underlying network is not shared by other applications running. This is a major concern provided that in modern data centers (aka Clouds), the networking infrastructure is shared by several applications. The consequence is that, in such environments, uniform total order broadcast protocols exhibit unstable behaviors. In this thesis, I present MDC-cast a new protocol for total order broadcasts that is optimized for multi-data center environments. MDC-cast combines the benefits of IP-multicast in cluster environments and TCP/IP unicast to get a hybrid algorithm that achieves very good performance in modern datacenters.