Communications of the ACM

fore the cloud was a thing, the idea of a utility model of computing is more important than ever. For practitioners of today, OceanStore demonstrates that it is possible to create a utility-provider model of computing even with a widely distributed infrastructure controlled by a number of administrative entities.

Final Thoughts

Because edge computing is a rapidly evolving field with a large number of potential applications, it should be on every practitioner’s radar. While a number of existing applications can benefit immediately from edge computing resources, a whole new set of applications will emerge as a result of having access to such infrastructures. The emergence of edge computing does not mean cloud computing will vanish or become obsolete, as there will always be applications that are better suited to being run in the cloud.

This article merely scratches the surface of a vast collection of knowledge. A key lesson, however, is that creating familiar gateways and providing API uniformity are merely facades; infrastructures and services are needed to address the core challenges of edge computing in a more fundamental way.

Tackling management complexity and heterogeneity will probably be the biggest hurdle in the future of edge computing. The other big challenge for edge computing will be data management. As data becomes more valuable than ever, security and privacy concerns will play an important role in how edge computing architectures and applications evolve. In theory, edge computing makes it possible to restrict data to specific domains of trust for better information control. What happens in practice remains to be seen.

Cloud computing taught practitioners how to scale resources within a single administrative domain. Edge computing requires learning how to scale in the number of administrative domains.

Nitesh Mor is a Ph. D. candidate in computer science at the University of California, Berkeley. He is currently part of the Global Data Plane project at the Ubiquitous Swarm Lab at UC Berkeley, where he focuses on secure Internetwide infrastructures for data storage and communication.

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storage. Note that while many aspects of the vision may seem like a trivial task with the cloud computing resources of today, this paper predates the cloud by almost a decade.

OceanStore: An Architecture for Global-Scale Persistent Storage

J. Kubiatowicz et al.

ACM SIGOPS Operating Systems Review 34, 5 (2000), 190–201; https://dl.acm.org/citation. cfm?id=357007

OceanStore assumes a fundamentally untrusted infrastructure composed of geographically distributed servers and provides storage as a service. Data is named by globally unique identifiers (GUIDs) and is portrayed as nomadic (that is, it can flow freely and can be cached anywhere, anytime). The underlying network is essentially a structured P2P (peer-to-peer) network that routes data based on the GUIDs. The routing is performed using a locality-aware, distributed routing algorithm.

Updates to the objects are cryptographically signed and are associated with predicates that are evaluated by a replica. Based on such evaluation, an update can be either committed or aborted. Further, these updates are serialized by the infrastructure using a primary tier of replicas running a Byzantine agreement protocol, thus removing the trust in any single physical server or provider. A larger number of secondary replicas are used to enhance durability. In addition, data is replicated widely for archival storage by using erasure codes.

While OceanStore has a custom API to the system, it provides “facades” that could offer familiar interfaces—such as a filesystem—to legacy applications. This is a vision paper with enough details to convince readers that such a system can actually be built.

In fact, OceanStore had a follow-up prototype implementation named Pond ( https://bit.ly/2SAlJie). In a way, OceanStore can be considered a two-part system: An information-centric network underneath and a storage layer on top that provides update semantics on objects. Combined with the secure execution of Intel SGX-like solutions, it should be possible, in theory, to run end-to-end secure applications.