Uncertainty in Global Application Services with Load Sharing Policy

Abstract

Abstract. With many organizations now employing multiple data centres around the world to share global traffic load, it is important to understand the effects of geographical distribution on service quality. The Domain Name Service is an important component for global load balancing. Using controllable simulations, we show that wide area sharing can play an important role in optimization of response times when traffic levels exceed that which can be supplied by a local infrastructure. We compute the probability of being able to meet Service Level Objectives as a function of DNS caching policy (Time To Live), so that service providers can account for DNS error margins in Service Level Agreements.