AWAIT: Efficient Overload Management for Busy Multi-tier Web Services under Bursty Workloads

Abstract

Abstract. The problem of service differentiation and admission control in web services that utilize a multi-tier architecture is more challenging than in a singletiered one, especially in the presence of bursty conditions, i.e., when arrivals of user web sessions to the system are characterized by temporal surges in their arrival intensities and demands. We demonstrate that classic techniques for a session based admission control that are triggered by threshold violations are ineffective under bursty workload conditions, as user-perceived performance metrics rapidly and dramatically deteriorate, inadvertently leading the system to reject requests from already accepted user sessions, resulting in business loss. Here, as a solution for service differentiation of accepted user sessions we promote a methodology that is based on blocking, i.e., when the system operates in overload, requests from accepted sessions are not rejected but are instead stored in a blocking queue that effectively acts as a waiting room. The requests in the blocking queue implicitly become of higher priority and are served immediately after load subsides. Residence in the blocking queue comes with a performance cost as blocking time adds to the perceived end-to-end user response time. We present a novel autonomic session based admission control policy, called AWAIT, that adaptively adjusts the capacity of the blocking queue as a function of workload burstiness in order to meet predefined user service level objectives while keeping the portion of aborted accepted sessions to a minimum. Detailed simulations illustrate the effectiveness of AWAIT under different workload burstiness profiles and therefore strongly argue for its effectiveness.

Distributed resource management across process boundaries

“…User code in Wisp can use these techniques to gracefully degrade service. [23,33,44,75] are potential admission control policies for Wisp. [59] focuses on the design of distributed rate limiters for network flows.…”

Priority Access Mechanism for Improving Responsiveness to Users Through Cache Server and Priority Access Management Mechanism

“…Lu, L., Cherkasova, L., de Nitto Personè, V., Mi, N., and Smirni, E. presented "a novel autonomic session based admission control policy" [2]. It uses queue to control the number of active simultaneous processing accesses and the number of maximum acceptance accesses, and reject accesses over maximum acceptance number.…”

Modelos de negócio para ambientes de computação em nuvem que consideram atributos de qos relacionados a desempenho e a segurança

“…Para situações com rajadas, a carga de trabalho é modelada com base nas metodologias encontradas na literatura (LU et al, 2010) (YIN et al, 2014). Na maioria desses trabalhos, as cargas de trabalho que se apresentam em forma de rajadas são modeladas como um processo estocástico, usando a classe MAP, para capturar as características e propriedades deste tipo de carga, como alta variabilidade e chegadas de requisições em forma condensada em curtos períodos ao longo do tempo.…”