TY - JOUR
T1 - Stochastic Model for QoS Assessment in Multi-tier Web Services
AU - Czekster, Ricardo M.
AU - Fernandes, Paulo
AU - Sales, Afonso
AU - Webber, Thais
AU - Zorzo, Avelino F.
PY - 2011/9/27
Y1 - 2011/9/27
N2 - Service Level Agreements (SLAs) are used to guarantee quality of service (QoS) between customers and service providers. In an SLA, parties establish a common set of rules and responsibilities. In this paper we propose a practical stochastic modeling of a multi-tier architecture considering SLAs for specific transactions. The model is parameterized with available performance testing data for a real web service, and with a testing environment having unpredictable and unknown external workloads of simultaneous execution. In addition, we present multiple scenarios of external applications impacting on the SLAs in our target architecture. Having a previous knowledge about the average time demanded by some external applications, our model results can provide evidences when the system under test will not respect the agreed-upon SLAs. Finally, we discuss possible model extensions towards further unknown workload characterizations and considerations about application execution profiling.
AB - Service Level Agreements (SLAs) are used to guarantee quality of service (QoS) between customers and service providers. In an SLA, parties establish a common set of rules and responsibilities. In this paper we propose a practical stochastic modeling of a multi-tier architecture considering SLAs for specific transactions. The model is parameterized with available performance testing data for a real web service, and with a testing environment having unpredictable and unknown external workloads of simultaneous execution. In addition, we present multiple scenarios of external applications impacting on the SLAs in our target architecture. Having a previous knowledge about the average time demanded by some external applications, our model results can provide evidences when the system under test will not respect the agreed-upon SLAs. Finally, we discuss possible model extensions towards further unknown workload characterizations and considerations about application execution profiling.
KW - Analytical Modeling
KW - Performance Evaluation
KW - Quality of Service
KW - Service Level Agreements
KW - Stochastic Automata Networks
UR - http://www.scopus.com/inward/record.url?scp=80054978939&partnerID=8YFLogxK
U2 - 10.1016/j.entcs.2011.09.005
DO - 10.1016/j.entcs.2011.09.005
M3 - Article
AN - SCOPUS:80054978939
SN - 1571-0661
VL - 275
SP - 53
EP - 72
JO - Electronic Notes in Theoretical Computer Science
JF - Electronic Notes in Theoretical Computer Science
IS - 1
ER -