Performance Testing of Distributed Component Architectures

Performance characteristics, such as response time, throughput andscalability, are key quality attributes of distributed applications. Current practice,however, rarely applies systematic techniques to evaluate performance characteristics.We argue that evaluation of performance is particularly crucial in early developmentstages, when important architectural choices are made. At first glance, thiscontradicts the use of testing techniques, which are usually applied towards the endof a project. In this chapter, we assume that many distributed systems are builtwith middleware technologies, such as the Java 2 Enterprise Edition (J2EE) or theCommon Object Request Broker Architecture (CORBA). These provide servicesand facilities whose implementations are available when architectures are defined.We also note that it is the middleware functionality, such as transaction and persistenceservices, remote communication primitives and threading policy primitives,that dominates distributed system performance. Drawing on these observations, thischapter presents a novel approach to performance testing of distributed applications.We propose to derive application-specific test cases from architecture designs so thatthe performance of a distributed application can be tested based on the middlewaresoftware at early stages of a development process. We report empirical results thatsupport the viability of the approach

Modeling and Generating Tailored Distribution Middleware for Embedded Real-Time Systems

International audienceDistributed real-time embedded (DRE) systems are becoming increasingly complex. They have to meet more and more stringent requirements, either functional or non-functional. Because of this, DRE systems development makes use of formal methods for verification; and, in some cases, generation of proven code. The distribution aspects are typically handled by a middleware, which must meet the system constraints. In this article, we describe our approach to model and generate middleware-based distributed systems for DRE applications. Our methodology is a three-step approach. First, we model the high-level inter-component interactions using connectors. We then use the Architecture Analysis and Design Language (AADL) as a pre-implementation description language to capture all the non-functional aspects of the system. Finally, we generate actual application code and the appropriate middleware from the AADL description. In order to demonstrate the feasibility of our approach, we created an application generator, Gaia. It is part of the Ocarina AADL tool suite and generates application source code for use with the PolyORB middleware

Integration of Data Distribution Service and distributed partitioned systems

[EN] Avionics systems are complex and time-critical systems that are progressively adopting more flexible (though equally robust) architectural designs. Although a number of current avionics systems follow federated architectures, the Integrated Modular Avionics (IMA) paradign is becoming the dominant style in the more modern developments. The reason is that the IMA concept promotes modular designs where applications with different levels of criticality can execute in an isolated manner in the same hardware. This approach complies with the requirements of cost, safety, and weight of the avionics systems. FACE standard (Future Airborne Capability Environment) defines the architectural baseline for easing integration in avionics systems, including the communication functions across distributed components. As specified in FACE, middleware will be integrated into avionics systems to ease development of portable components that can interoperate effectively. This paper describes the usage of publish-subscribe middleware (precisely, DDS - Data Distribution Service for real-time systems) into a fully distributed partitioned system. We describe, from a practical point of view, the integration of the middleware communication overhead into the hierarchical scheduling (as compliant with ARINC 653) to allow the usage of middleware in the partitions. We explain the design of a realiable communication setting, exemplified on a distributed monitoring application in a partitioned environment. The obtained implementation results show that, given the stable communication overhead of the middleware, it can be integrated in the time windows of partitions.This work has been partly supported by the Spanish Ministry of Economy and Competitiveness through projects REM4VSS (TIN 2011-28339) and M2C2 (TIN2014-56158-C4-3-P).Garcia-Valls, M.; Domínguez-Poblete, J.; Eddine Touahria, I.; Lu, C. (2018). Integration of Data Distribution Service and distributed partitioned systems. Journal of Systems Architecture. 83:23-31. https://doi.org/10.1016/j.sysarc.2017.11.00123318

CORBA: A Quantitative and Qualitative Comparison of Industrial Strength, Commercial CORBA ORBs for the JAVA Platform

In distributed systems design, middleware is a key component. Middleware establishes the communication between a client and server in a multi-tiered architecture. One approach to middleware is implementing the OMG\u27s CORBA standard, through the use of ORBs. Three of the more popular commercially available ORBs are Sun\u27s Java 2 ORB, Borland\u27s VisiBroker for Java, and IONA\u27s Orbix 2000 for Java. The purpose of this graduate project was to compare the three ORBs both quantitatively and qualitatively. The project compares the ORBs quantitatively by measuring the performance of each ORB, in terms of response time. The comparison was done qualitatively by looking at the services each ORB provides, the level of ease of implementing a simple, client-server application in each ORBs\u27 syntax, the time taken to develop each application, difficulties encountered, and the stability of each ORB when tested. The results of the project should prove to be useful for distributed systems designers, and for researchers studying middleware products. In addition, each of the applications created for the project can be re-used for any future performance or load testing of the ORBs one might want to conduct

Ensuring Cyber-Security in Smart Railway Surveillance with SHIELD

Modern railways feature increasingly complex embedded computing systems for surveillance, that are moving towards fully wireless smart-sensors. Those systems are aimed at monitoring system status from a physical-security viewpoint, in order to detect intrusions and other environmental anomalies. However, the same systems used for physical-security surveillance are vulnerable to cyber-security threats, since they feature distributed hardware and software architectures often interconnected by ‘open networks’, like wireless channels and the Internet. In this paper, we show how the integrated approach to Security, Privacy and Dependability (SPD) in embedded systems provided by the SHIELD framework (developed within the EU funded pSHIELD and nSHIELD research projects) can be applied to railway surveillance systems in order to measure and improve their SPD level. SHIELD implements a layered architecture (node, network, middleware and overlay) and orchestrates SPD mechanisms based on ontology models, appropriate metrics and composability. The results of prototypical application to a real-world demonstrator show the effectiveness of SHIELD and justify its practical applicability in industrial settings

Software engineering and middleware: a roadmap (Invited talk)

The construction of a large class of distributed systems can be simplified by leveraging middleware, which is layered between network operating systems and application components. Middleware resolves heterogeneity and facilitates communication and coordination of distributed components. Existing middleware products enable software engineers to build systems that are distributed across a local-area network. State-of-the-art middleware research aims to push this boundary towards Internet-scale distribution, adaptive and reconfigurable middleware and middleware for dependable and wireless systems. The challenge for software engineering research is to devise notations, techniques, methods and tools for distributed system construction that systematically build and exploit the capabilities that middleware deliver

The MIDdleware Assurance Substrate: Enabling Strong Real-Time Guarantees in Open Systems With OpenFlow

Middleware designed for use in Distributed Real-Time and Embedded (DRE) systems enable cost and development time reductions by providing simple communications abstractions and hiding operating system-level networking API details from developers. While current middleware technologies can hide many low-level details, designers must provide a static configuration for the system’s underlying network in order to achieve required performance characteristics. This has not been a problem for many types of DRE systems where the configuration of the system is relatively fixed from the factory (e.g., aircraft or naval vessels). However for truly open systems (i.e., systems where end users can add or subtract components at runtime) the standard static network configuration approach cannot guarantee that required performance will be met because network resource demands are not fully known a priori. Open systems with stringent performance requirements need middleware that can dynamically manage the underlying network configuration automatically in response to changing demands. Fortunately, recent trends in networking have resulted in a wide variety of networking equipment that expose a standardized low-level interface to their configuration via the OpenFlow protocol. In this paper we discuss how OpenFlow can be leveraged by DRE middleware to automatically provide performance guarantees. In order to make the discussion concrete, we describe the architecture of our prototype middleware MIDAS as well as the details of one example network resource management strategy. We demonstrate the feasibility of our approach via performance assesment of a simple DRE application using our MIDAS and commerically available OpenFlow hardware

Middleware Technologies for Cloud of Things - a survey

The next wave of communication and applications rely on the new services provided by Internet of Things which is becoming an important aspect in human and machines future. The IoT services are a key solution for providing smart environments in homes, buildings and cities. In the era of a massive number of connected things and objects with a high grow rate, several challenges have been raised such as management, aggregation and storage for big produced data. In order to tackle some of these issues, cloud computing emerged to IoT as Cloud of Things (CoT) which provides virtually unlimited cloud services to enhance the large scale IoT platforms. There are several factors to be considered in design and implementation of a CoT platform. One of the most important and challenging problems is the heterogeneity of different objects. This problem can be addressed by deploying suitable "Middleware". Middleware sits between things and applications that make a reliable platform for communication among things with different interfaces, operating systems, and architectures. The main aim of this paper is to study the middleware technologies for CoT. Toward this end, we first present the main features and characteristics of middlewares. Next we study different architecture styles and service domains. Then we presents several middlewares that are suitable for CoT based platforms and lastly a list of current challenges and issues in design of CoT based middlewares is discussed.Comment: http://www.sciencedirect.com/science/article/pii/S2352864817301268, Digital Communications and Networks, Elsevier (2017