On the Integration of Automatic Deployment into the ABS Modeling Language

Abstract

Abstract. In modern software systems, deployment is an integral and critical part of application development (see, e.g., the DevOps approach to software development). Nevertheless, deployment is usually overlooked at the modeling level, thus losing the possibility to perform deployment conscious decisions during the early stages of development. In this paper, we address the problem of promoting deployment as an integral part of modeling, by focusing on the Abstract Behavioral Specification (ABS) language used for the specification of models of systems composed of concurrent objects consuming resources provided by deployment components. We extend ABS with class annotations expressing the resource requirements of the objects of that class. Then we define a tool that, starting from a high-level declaration of the desired system, computes a model instance of such system that optimally distributes objects over available deployment components.

On the modeling of optimal and automatized cloud application deployment

“…Also the initial system deployment, as well as the dynamic re-150 deployment procedures, computed by the automatic solver have been analysed and validated by the operations team. This paper finalizes the work started in [14,15] where the first version of SmartDepl has been presented. Compared with what presented in these papers, 160 the current version of SmartDepl has been completely rewritten and extended to overcome the original limitations: new annotations are supported, for instance, to express preferences over bindings (e.g., useful to specify deployment optimization criteria based on geographical proximity), to indicate methods to be invoked on already present objects to notify the deployment of new objects 165 (e.g., useful to break circularity in the object dependency relation), and to fix an ordering on these methods (e.g., useful to notify the deployment of the new object following a user-defined ordering).…”

“…We are not aware of other approaches that used formal tools to optimize the deployment of applications at the modeling level. Our approach, which is inspired by [8] and significantly improves our initial work [14], can be easily applied to any other object-oriented language 1525 that offers primitives for the acquisition and release of computing resources.…”

Automatic Deployment of Services in the Cloud with Aeolus Blender

“…Since there is no standard benchmark for application deployment, as a future work we plan to define qualitative and quantitative evaluation mechanisms by first describing a series of deployment tasks that can later be used to evaluate both the improvements of future Blender versions and for comparison with possible future competitors. Moreover, as done in [12], we would like to compare the quality of the automatically generated deployment plans against those (manually) devised by DevOps. Since Blender always produces an optimal final configuration, its solution can be used to prove that an existing handmade solution is optimal.…”

Declarative Elasticity in ABS

“…our approach is declarative: the programmer specifies deployment constraints and a solver computes actual deployments satisfying such constraints. In previous work [10] we presented an external engine able to synthesize ABS code specifying the initial static deployment; in this paper we fully integrate this approach in the ABS language allowing for the declarative specification of the incremental upscale/downscale of the modeled application depending, e.g., on the monitored workload or the current level of resource usage.…”

“…Our initial proposal for the declarative modeling of deployment into ABS [10] was based on three main pillars: (i) classes are enriched with annotations that indicate functional dependencies of objects of those classes as well as the resources they require, (ii) a separate high-level language for the declarative specification of the deployment, (iii) an engine that, based on the annotations and the programmer's requirements, computes a fully specified deployment that minimizes the total cost of the system. The computed deployment is expressed in ABS and can be manually included in a main block.…”