ACMS: The Akamai Configuration Management System

increasingly large distributed systems to deploy increasingly complex and mission-critical applications. In order for these systems to achieve the ultimate goal of having similar easeof-use properties as centralized systems they must allow fast, reliable, and lightweight management and synchronization of their configuration state. This goal poses numerous technical challenges in a truly Internet-scale system, including varying degrees of network connectivity, inevitable machine failures, and the need to distribute information globally in a fast and reliable fashion. In this paper we discuss the design and implementation of a configuration management system for the Akamai Network. It allows reliable yet highly asynchronous delivery of configuration information, is significantly fault-tolerant, and can scale if necessary to hundreds of thousands of servers. The system is fully functional today providing configuration management to over 15,000 servers deployed in 1200+ different networks in 60+ countries.

Abstract Web caching with consistent hashing

A key performance measure for the World Wide Web is the speed with which content is served to users. As traffic on the Web increases, users are faced with increasing delays and failures in data delivery. Web caching is one of the key strategies that has been explored to improve performance. An important issue in many caching systems is how to decide what is cached where at any given time. Solutions have included multicast queries and directory schemes. In this paper, we offer a new Web caching strategy based on consistent hashing. Consistent hashing provides an alternative to multicast and directory schemes, and has several other advantages in load balancing and fault tolerance. Its performance was analyzed theoretically in previous work; in this paper we describe the implementation of a consistent-hashing-based system and experiments that support our thesis that it can provide performance improvements