Middleware and Application Management Architecture

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Middleware and Application Management Architecture Middleware and Application Management Architecture vorgelegt vom Diplom-Informatiker Sven van der Meer aus Berlin von der Fakultät IV – Elektrotechnik und Informatik der Technischen Universität Berlin zur Erlangung des akademischen Grades Doktor der Ingenieurwissenschaften - Dr.-Ing. - genehmigte Dissertation Promotionsausschuss: Vorsitzender: Prof. Gorlatch Berichter: Prof. Dr. Dr. h.c. Radu Popescu-Zeletin Berichter: Prof. Dr. Kurt Geihs Tag der wissenschaftlichen Aussprache: 25.09.2002 Berlin 2002 D 83 Middleware and Application Management Architecture Sven van der Meer Berlin 2002 Preface Abstract This thesis describes a new approach for the integrated management of distributed networks, services, and applications. The main objective of this approach is the realization of software, systems, and services that address composability, scalability, reliability, and robustness as well as autonomous self-adaptation. It focuses on middleware for management, control, and use of fully distributed resources. The term integra- tion refers to the task of unifying existing instrumentations for middleware and management, not their replacement. The rationale of this work stems from the fact, that the current situation of middleware and management systems can be described with the term interworking. The actually needed integration of management and middleware concepts is still an open issue. However, identified trends in communications and computing demand for integrated concepts rather than the definition of new interworking scenarios. Distributed applications need to be prepared to be used and operated in a stable, secure, and efficient way. Middleware and service platforms are employed to solve this task. To guarantee this objective for a long-time operation, the systems needs to be controlled, administered, and maintained in its entirety, supporting the general aim of the system, and for each individual component, to ensure that each part of the system functions perfectly. Management systems are responsible for this objective. Usage and control result in mechanisms for mapping information across application, service, and network level. Control, administration, and maintenance reflect management tasks on each of those levels. Integration of middle- ware and management results in a system that provides distributed applications with all of the introduced functionality. Following the hypothesis of this work, the target environments are evaluated to extract requirements for the integrated approach. Based on this evaluation, a general framework is developed that clearly identifies the certain levels of integration, their boundaries, and their individual objectives. Goal of the framework is to establish a software layer between the applications and distributed technologies that provides inte- grated management services without loosing the advantages of middleware. The approach is discussed in three steps. First, a general framework is defined based on the hypothesis and an evaluation of the target environments. The second step is the derivation of a Middleware and Ap- plication Management Architecture (MAMA) from this general framework. The last step is the realization of this architecture and its exploitation. The result is a software system that decouples distributed applications from concrete middleware and management technologies. The system’s functionality is offered to applications via an Application Pro- gramming Interface (API), which provides access to basic middleware and management facilities. The API is supported by an Application Definition Language that combines interface definitions with seman- tic information in order to enable automated processes for control and maintenance. Furthermore, applica- tion services are included to realize standard features such as naming, service lookup and discovery, event notification, and visual administration. The approach described in this thesis recognizes international standards and developments. In fact, the approach depends on commonly used and well-agreed technologies from the areas of telecommunica- tions, computing, syntax notations, distributed systems, systems management, and user interfaces. Middleware and Application Management Architecture i Preface ii Middleware and Application Management Architecture Preface Zusammenfassung Die Dissertation zum Thema: Middleware and Application Management Architecture beschreibt einen neuen Zugang für ein integriertes Managementsystem für verteilte Netzwerke, Dienst und Anwendungen. Das Hauptziel dieses Ansatzes ist ein Softwaresystem mit Diensten, welche Komponierbarkeit, Skalier- barkeit, Zuverlässigkeit und Robustheit genau so wie autonome Selbstanpassung ermöglichen. Es kon- zentriert sich auf Middleware für Management und Kontrolle sowie auf die Nutzung für verteilte Kompo- nenten. Der Begriff Integration beinhaltet in dieser Arbeit die Vereinigung existierender Instrumente von Middleware und Management, aber keineswegs ihre Ersetzung. Die Ausgangslage dieser Arbeit ist die Tatsache, dass die aktuelle Situation des Verhältnisses von Midd- leware und Management lediglich als Zusammenarbeit bezeichnet werden kann. Bekannte qualitative und quantitative Tendenzen in der Kommunikation und Datenverarbeitung verlangen nach integrierten Kon- zepten anstelle immer neuer Szenarien der Zusammenarbeit in spezifischen Konstellationen, die wie In- seln vielfältige spezifische Brücken zueinander benötigen. Die sich daraus ergebende Notwendigkeit ei- ner Integration von Middleware- und Management-Konzeptionen ist nach wie vor ein ungelöstes Prob- lem. Auf diesem Hintergrund wurde die vorliegende Arbeit konzipiert. Es wird ein Modell für die Integration von Middleware und Management begründet, entwickelt und seine Funktionsfähigkeit nachgewiesen. Es stellt ein System dar, welches verteilte Anwendungen mit allen wesentlichen Funktionen ausstattet: Ver- teilte Anwendungen müssen so beschaffen sein, dass sie stabil, sicher und effizient genutzt und betrieben werden können. Middleware und Dienstleistungsplattformen werden eingesetzt, um diese Aufgaben zu erfüllen. Um diesen Zweck über große Zeiträume hinweg zu garantieren, muss das integrierte System in seiner Gesamtheit kontrolliert, verwaltet und gewartet werden. Damit werden das grundsätzliche Ziel des Systems und die Aufgabe jeder einzelnen Komponente unterstützt und gesichert, dass jeder Bestandteil des Systems selbständig und im Zusammenwirken ordnungsgemäß funktioniert. Managementsysteme sind für diese Zielstellung verantwortlich. Nutzung und Kontrolle verlangen einen Mechanismus zur In- formationsumwandlung zwischen den Ebenen Anwendung, Dienste und Netzwerke. Zugleich sind Kon- trolle, Verwaltung und Wartung auf jeder dieser Ebenen erforderlich. Der Zielstellung dieser Arbeit folgend, ein funktionsfähiges Systems der Integration zu erarbeiten wel- ches den gestellten Anforderungen gerecht wird, werden die Zielumgebungen analysiert, um deren An- forderungen an einen integrierten Ansatz zu bestimmen. Basierend auf dieser Analyse wird dann ein ge- nerelles Rahmenwerk entworfen, das exakt die einzelnen Ebenen für eine Integration definiert, ebenso die Teilziele der einzelnen Ebenen wie auch die Grenzen zwischen ihnen. Hauptziel des Rahmenwerkes ist die Definition einer Schnittstelle zwischen Anwendungen und verteilten Technologien, die integrierte Verwaltungsdienste realisiert ohne die Vorteile von Middleware zu verlieren. Dieser Ansatz wird in drei Schritten dargelegt. Als erstes wird das generelle Rahmenwerk definiert, wel- ches auf der Grundthese und der Analyse der Einsatzgebiete beruht. Von diesem Rahmenwerk wird eine Architektur abgeleitet. Der letzte Schritt besteht in der Realisierung, Implementierung und Verwertung dieser Architektur in geeigneten Szenarien. Als Ergebnis der Arbeit entsteht ein Softwaresystem, das verteilte Anwendungen von konkreten Middle- ware- und Managementtechnologien abkoppelt. Dieses Systems und seine Funktionen wird den Anwen- dungen über eine entsprechende Programmierschnittstelle zur Verfügung gestellt. Diese bietet Zugang zu fundamentalen Middleware und Managementdiensten. Das wird von einer formalen Sprache unterstützt, die neben der herkömmlichen Definition von Objektschnittstellen auch semantische Bezüge der Anwen- dungen spezifizieren kann, um automatische Kontroll- und Wartungsprozesse zu ermöglichen. Weiterhin beinhaltet das System Basisdienste für die Anwendungen, wie zum Beispiel die Verwaltung von Namen, das automatische Suchen von Diensten, Nachrichtenverteilung, und grafische Verwaltung. Der Ansatz, der in der vorliegenden Arbeit beschrieben wird, verwendet internationale Standards. Er ba- siert auf weit verbreiteten und allgemein anerkannten Technologien aus den Bereichen Telekommunikati- on, Computer, formale Sprachen, verteilte Systeme, Systemverwaltung und Benutzerschnittstellen. Middleware and Application Management Architecture iii Preface iv Middleware and Application Management Architecture Preface Acknowledgements I would rather be attacked than unnoticed. For the worst thing you can do to an author is to be silent as to his works. Samuel Johnson There have been three men that, to follow the citation, ‘attacked’ constantly. The first of them has been my mentor, Prof. Radu Popescu-Zeletin. I extend my gratitude to him for giv- ing me the opportunity to work in the unequaled combination of the department for Open Communication System (at Technical University Berlin) and the Competence Center for Open Communication Systems (at Fraunhofer FOKUS).
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