Xcast

Source-specific multicast

Bandwidth (computing)

Multicast address

Operating system

Scalability

Computer science

Cloud computing

Pragmatic General Multicast

Distributed computing

Computer network

Multicast

Overlay multicast

Distance Vector Multicast Routing Protocol

IP multicast

Unicast

Wireless

Throughput

Protocol Independent Multicast

Overlay

We present Elmo, a system that addresses the multicast scalability problem in multi-tenant datacenters. Modern cloud applications frequently exhibit one-to-many communication patterns and, at the same time, require sub-millisecond latencies and high throughput. IP multicast can achieve these requirements but has control- and data-plane scalability limitations that make it challenging to offer it as a service for hundreds of thousands of tenants, typical of cloud environments. Tenants, therefore, must rely on unicast-based approaches (e.g., application-layer or overlay-based) to support multicast in their applications, imposing bandwidth and end-host CPU overheads, with higher and unpredictable latencies.

Elmo