International audienceTo program parallel systems efficiently and easily, a wide range of programming models have been proposed, each with different choices concerning synchronization and communication between parallel entities. Among them, the actor model is based on loosely coupled parallel entities that communicate by means of asynchronous messages and mailboxes. Some actor languages provide a strong integration with object-oriented concepts; these are often called active object languages. This paper reviews four major actor and active object languages and compares them according to carefully chosen dimensions that cover central aspects of the programming paradigms and their implementation

Abstract-The ever-growing trend of deploying applications over the Internet has resulted in increasingly tougher constraints and requirements. Data management systems are a major concern when it comes to scalability, flexibility and reliability due to being implemented in a distributed way. In this paper we present a Distributed Data Aggregation Service relying on a storage system designed to meet these demands, namely BlobSeer. The primary goal is to serve as a repository backend for complex analysis and automatic mining of scientific data (like bibtex entries). Several requirements, derived from this objective, match BlobSeer's features: versioning used for lock-free access to data and different granularity of read / write operations. We proposed a model to perform the correct translation between BlobSeer's unstructured view of data and the user's structured view. We implemented a client providing a formal description for the data retrieval queries and a specification for a search API. A benchmark tool relying on a performance model of BlobSeer, will be used to automatically determine the best BlobSeer deployment configuration for a specific data aggregation pattern.

Abstract. In this paper we present an API to support modeling applications with Actors based on the paradigm of the Abstract Behavioural Specification (ABS) language. With the introduction of JAVA 8, we expose this API through a JAVA library to allow for a high-level actorbased methodology for programming distributed systems which supports the programming to interfaces discipline. We validate this solution through a case study where we obtain significant performance improvements as well as illustrating the ease with which simple high and low-level optimizations can be obtained by examining topologies and communication within an application. Using this API we show it is much easier to observe drawbacks of shared data-structures and communications methods in the design phase of a distributed application and apply the necessary corrections in order to obtain better results.

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SUMMARYCloud environments have become a standard method for enterprises to offer their applications by means of web-services, data management systems or simply renting out computing resources. In our previous work we presented how we can use a modeling language together with the new features of JAVA 8 to overcome certain drawbacks of data structures and synchronization mechanisms in parallel applications. We extend this solution into a design pattern that allows application-specific optimizations in a distributed setting. We validate this integration using our previous case study of the Prime Sieve of Eratosthenes and illustrate the performance improvements in terms of speed-up and memory consumption.