The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Probabilistic quorum systems can tolerate a larger fraction of faults than can traditional (strict) quorum systems, while guaranteeing consistency with an arbitrarily high probability for a system with enough replicas. However, the masking and opaque types of probabilistic quorum systems are hampered in that their optimal load—a best-case measure of the work done by the busiest replica, and an indicator...
Byzantine-fault-tolerant service protocols like Q/U and FaB Paxos that optimistically order requests can provide increased efficiency and fault scalability. However, these protocols require n ≥ 5b+ 1 servers (where b is the maximum number of faults tolerated), owing to their use of opaque Byzantine quorum systems; this is 2b more servers than required by some non-optimistic protocols. In this paper,...
Over the past decade, work on quorum systems in non-traditional scenarios has facilitated a number of advances in the field of distributed systems. This chapter surveys a selection of these results including: Byzantine quorum systems that are suitable for use when parts of the system cannot be trusted; algorithms for the deployment of quorum systems on wide area networks so as to allow for efficient...