Fast dynamic deployment adaptation for mobile devices

Mobile devices that are limited in terms of CPU power, memory or battery power are only capable of executing simple applications. To be able to run advanced applications we introduce a framework to split up the application and execute parts on a remote server. In order to dynamically adapt the deployment at runtime, techniques are presented to keep the migration time as low as possible and to prevent performance loss while migrating. Also methods are presented and evaluated to cope with applications generating a variable load, which can lead to an unstable system

Adaptive online deployment for resource constrained mobile smart clients

Nowadays mobile devices are more and more used as a platform for applications. Contrary to prior generation handheld devices configured with a predefined set of applications, today leading edge devices provide a platform for flexible and customized application deployment. However, these applications have to deal with the limitations (e.g. CPU speed, memory) of these mobile devices and thus cannot handle complex tasks. In order to cope with the handheld limitations and the ever changing device context (e.g. network connections, remaining battery time, etc.) we present a middleware solution that dynamically offloads parts of the software to the most appropriate server. Without a priori knowledge of the application, the optimal deployment is calculated, that lowers the cpu usage at the mobile client, whilst keeping the used bandwidth minimal. The information needed to calculate this optimum is gathered on the fly from runtime information. Experimental results show that the proposed solution enables effective execution of complex applications in a constrained environment. Moreover, we demonstrate that the overhead from the middleware components is below 2%

Dynamic Proxies for Classes: Towards Type-Safe and Decoupled Remote Object Interaction

A dynamic proxy object is a typed proxy, created at runtime, conforming to a type specified by the application. Such an object can be used wherever an expression of the type it was created for is expected, yet reifies all invocations performed on it. This simple but powerful concept has been introduced into Java at version 1.3 (and has later also appeared in the .NET platform). A dynamic proxy is created for a set of interfaces as an instance of a class, generated automatically on the fly without support from the Java compiler or virtual machine, implementing those interfaces. Unfortunately, dynamic proxies are only available ``for interfaces''. The case of creating dynamic proxies for a set of types including a class type, due to the increased complexity, has not been considered, meaning that it is currently not possible to create a dynamic proxy mimicking an instance of a class. We present a pragmatic approach to supporting dynamic proxies ``for classes'', building on the existing solution to dynamic proxies for interfaces. We discuss the costs of such an extension, in terms of safety, security, and performance, and illustrate its usefulness through a novel abstraction for decoupled remote interaction, unifying (implicit future) remote method invocations and (type-based) publish/subscribe

A Bytecode Translator for Distributed Execution of “Legacy” Java Software

Abstract. This paper proposes a system named Addistant, which en-ables the distributed execution of “legacy ” Java bytecode. Here “legacy” means the software originally developed to be executed on a single Java virtual machine (JVM). For adapting legacy software to distributed ex-ecution on multiple JVM, developers using Addistant have only to spec-ify the host where instances of each class are allocated and how remote references are implemented. According to that specification, Addistant automatically transforms the bytecode at load time. A technical contri-bution by Addistant is that it covers a number of issues for implementing distributed execution in the real world. In fact, Addistant can adapt a legacy program written with the Swing library so that Swing objects are executed on a local JVM while the rest of objects are on a remote JVM.

Combining SOA and BPM Technologies for Cross-System Process Automation

This paper summarizes the results of an industry case study that introduced a cross-system business process automation solution based on a combination of SOA and BPM standard technologies (i.e., BPMN, BPEL, WSDL). Besides discussing major weaknesses of the existing, custom-built, solution and comparing them against experiences with the developed prototype, the paper presents a course of action for transforming the current solution into the proposed solution. This includes a general approach, consisting of four distinct steps, as well as specific action items that are to be performed for every step. The discussion also covers language and tool support and challenges arising from the transformation