Transactional Exactly-once
نویسنده
چکیده
A three-tier application is organized as three layers. Front end clients (e.g., browsers) with which human user interact; middle-tier servers (e.g., web servers) that contain the core business logic of the application; and back-end database servers against which application servers perform transactions. Although three-tier applications are nowadays mainstream, they usually fail to provide su cient reliability guarantees to the end users. Usually, ad-hoc replication and transactional techniques are developed for speci c parts of the application, but these techniques are not combined to provide some global notion of reliability. The aim of this paper is precisely to de ne a desirable, yet realistic, speci cation of end-toend reliability in three-tier applications. We present the speci cation in the form of a problem called Transactional Exactly-Once which encompasses both safety and liveness properties in such environments. We also describe a practical protocol that solves the problem and we discuss its implementation and performances in a practical setting.
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