Advances, Systems and Applications
From: Severity: a QoS-aware approach to cloud application elasticity
Benchmarking metric | Description |
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Availability | The percentage of time for which the workload pattern for a particular metric was not demanding more than the processing capacity of the infrastructure offered. We do not distinguish whether the processing capacity was exceeded by a small or large margin – in both cases the service is considered unavailable for the purpose of our experiments. Moreover, we considered that the lack of availability of the service at a particular instance of time does not influence the ability of the service to handle the workload correctly as soon as it receives the resources which are required. |
Overprovisioning | The product of the extraneous VM instances which were used (compared to the optimal) with the percentage of simulation time for which they were spawned. |
Rigidness | The time percentage of a simulation, for which the application was working either above or even below the rule thresholds set. For example, if a rule on a metric states that a scale out action should happen when the value of the metric surpasses 70%, while a scale in action should happen when the value of the metric drops below 30%, the system is considered to be exhibiting ‘rigidness’ when the value of the metric is greater than 70% or lower than 30%. |
Number of scaling adaptations | The total number of scaling adaptations (associated with an addition or removal of a number of VMs) which were performed by the platform. The first deployment is also counted in this number. |