Architectural Templates (ATs) are a method to formalise architectural styles on component models. This formalization is annotated with quality models for model-driven analyses. An example of such an annotation are CloudScale Architectural Templates.
CloudScale Architectural Templates
CloudScale Architectural Templates (CATs) are a refinement of Architectural Templates (ATs). While ATs allow arbitrary quality models to be annotated, CATs annotate only CloudScale's scalability model. This annotation allows architects to analyse the scalability of their SaaS applications.
A person exploiting services of a service provider. The term "service customer" can synonymously be used. Refinements of a "service customer" include "SaaS customer", "PaaS customer", and "IaaS customer". Other typical synonyms are "user" and "consumer", however, these synonyms should be avoided for clarity.
For an as-a-Service layer, elasticity is the degree to which the layer is able to adapt to workload changes by (de)provisioning services of its underlying layers in an autonomic manner such that at each point in time the utilised services fulfill the SLA of the layer as closely as possible.
Load is the characterisation of the quantity of requests at a given time, e.g., by characterising the request rate.
Metric is a procedure to determine a quantity. SaaS quantity metric: e.g., #IaaS + #PaaS services IaaS quantity metric: e.g., #CPU services, #CPU Minutes, #CPU Invocations
A person offering services. The term "service provider" can synonymously be used. Refinements of a "service provider" include "SaaS provider", "PaaS provider", and "IaaS provider".
Quantity is a property that can exist as a magnitude or multitude. [Wiki]
Special case of a service, however, without SLA. Should only be treated as special case or for giving examples.
Example SaaS stakeholders: SaaS End-users, SaaS provider, SaaS Architects, SaaS Developers, SaaS Deployers (work on PaaS/IaaS layer!), SaaS Maintainer, SaaS *Anyone*
For an as-a-Service layer, scalability is the ability of the layer to sustain increasing workloads while fulfilling its SLA, potentially by exploiting a higher quantity of lower layer services.
For the SaaS layer, scalability is the ability of the software to sustain increasing workloads while fulfilling its SLA, potentially by exploiting a higher quantity of PaaS or IaaS services.
Set of operations plus an SLA.
Work is the characterisation of the data to be processed by a certain layer.
Workload is the combined characterisation of work and load.