Design and implementation of a composable reflective middleware framework

Abstract

With the evolution of the global information infrastructure, service providers will need to provide effective and adaptive resource management mechanisms that can serve more concurrent clients and deal with applications that exhibit Quality of Service (QoS) requirements. Flexible, scalable and customizable middleware can be used as enabling technology for next generation systems that adhere to the QoS requirements of applications that execute in highly dynamic distributed environments. To enable application aware resource management, we are developing a customizable and composable middleware framework called CompOSE|Q based on a reflective metamodel. In this paper, we describe the architecture and runtime environment for CompOSE|Q and briefly assess the performance overhead of the additional flexibility. We also illustrate how flexible communication mechanisms can be supported efficiently in the CompOSE|Q framework.

Design and Performance of Asynchronous Method Handling for CORBA

“…Having an explicit asynchronous model offers more flexibility and dynamicity in the system since individual messages can be 'acted-upon'/transformed or rerouted easily [11]. However, this flexibility often yields lower performance, e.g., These types of systems have been known to perform around two orders of magnitude worse than synchronous systems in which initial connection setup takes time, but after the connection is established communication between the client and the server is fast [12].…”

Resolving feature convolution in middleware systems

“…The discussion of separation of concerns for the design of middleware platforms can be broadly classified into approaches that provide customization of the middleware through static or dynamic policy selection [1,34], approaches that adapt the operation of the middleware to changing runtime conditions through the use of reflection [7,25,24,5], and approaches based on various forms of aspect definitions and interpretations [26,32,19]. Many of these projects use several of these techniques in combination.…”

“…This includes projects such as openORB [7], openCORBA [25], dynamicTAO [24], the OpenOrb project [5], and also the CompOSE-Q project [34]. In these approaches, the reflective middleware implementation observes and reacts to changing environmental conditions by selecting different implementation strategies.…”

“…Astley et al [1] achieve middleware customization through techniques based on separation of communication styles from protocols and a framework for protocol composition. The CompOSE-Q [34] project uses an actor-based model for runtime adaptation. Both approaches do not employ aspect orientation to isolated crosscutting design concerns from the middleware implementation.…”

Transparent self-optimization in existing CORBA applications

“…To accomplish this task, we employ an adaptive middleware approach. Just as tra-ditional middleware hides distribution from an application, so can adaptive middleware hide automatic adaptation to changes in the execution environment, such as network connectivity, energy usage, and security policies [5][6][7][8][9][10][11][12][13]. Some adaptations are "generic," in that they are common to many, if not all, applications executing on the device.…”