Implementing autonomic administration DSLs in TUNe

Software components are recognized as the most adequate approach to support autonomic administration systems. We implemented and experimented with such a system, but observed that the interfaces of a component model are too low-level and difficult to use. Consequently, we designed higher abstraction level languages for modeling administration policies. These languages are specific to our autonomic administration domain. We metamodeled and implemented these DSLs on the Kermeta framework

Automatic performance optimisation of component-based enterprise systems via redundancy

Component technologies, such as J2EE and .NET have been extensively adopted for building complex enterprise applications. These technologies help address complex functionality and flexibility problems and reduce development and maintenance costs. Nonetheless, current component technologies provide little support for predicting and controlling the emerging performance of software systems that are assembled from distinct components. Static component testing and tuning procedures provide insufficient performance guarantees for components deployed and run in diverse assemblies, under unpredictable workloads and on different platforms. Often, there is no single component implementation or deployment configuration that can yield optimal performance in all possible conditions under which a component may run. Manually optimising and adapting complex applications to changes in their running environment is a costly and error-prone management task. The thesis presents a solution for automatically optimising the performance of component-based enterprise systems. The proposed approach is based on the alternate usage of multiple component variants with equivalent functional characteristics, each one optimized for a different execution environment. A management framework automatically administers the available redundant variants and adapts the system to external changes. The framework uses runtime monitoring data to detect performance anomalies and significant variations in the application's execution environment. It automatically adapts the application so as to use the optimal component configuration under the current running conditions. An automatic clustering mechanism analyses monitoring data and infers information on the components' performance characteristics. System administrators use decision policies to state high-level performance goals and configure system management processes. A framework prototype has been implemented and tested for automatically managing a J2EE application. Obtained results prove the framework's capability to successfully manage a software system without human intervention. The management overhead induced during normal system execution and through management operations indicate the framework's feasibility

Autonomic Management Policy Specification: from UML to DSML

International audienceAutonomic computing is recognized as one of the most promizing solutions to address the increasingly complex task of distributed environments' administration. In this context, many projects relied on software components and architectures to provide autonomic management frameworks. We designed such a component-based autonomic management framework, but observed that the interfaces of a component model are too low-level and difficult to use. Therefore, we introduced UML diagrams for the modeling of deployment and management policies. However, we had to adapt/twist the UML semantics in order to meet our requirements, which led us to define DSMLs. In this paper, we present our experience in designing the Tune system and its support for management policy specification, relying on UML diagrams and on DSMLs. We analyse these two approaches, pinpointing the benefits of DSMLs over UML

A framework for adaptive monitoring and performance management of component-based enterprise applications

Most large-scale enterprise applications are currently built using component-based middleware platforms such as J2EE or .NET. Developers leverage enterprise services provided by such platforms to speed up development and increase the robustness of their applications. In addition, using a component-oriented development model brings benefits such as increased reusability and flexibility in integrating with third-party systems. In order to provide the required services, the application servers implementing the corresponding middleware specifications employ a complex run-time infrastructure that integrates with developer-written business logic. The resulting complexity of the execution environment in such systems makes it difficult for architects and developers to understand completely the implications of alternative design options over the resulting performance of the running system. They often make incorrect assumptions about the behaviour of the middleware, which may lead to design decisions that cause severe performance problems after the system has been deployed. This situation is aggravated by the fact that although application servers vary greatly in performance and capabilities, many advertise a similar set of features, making it difficult to choose the one that is the most appropriate for their task. The thesis presents a methodology and tool for approaching performance management in enterprise component-based systems. By leveraging the component platform infrastructure, the described solution can nonintrusively instrument running applications and extract performance statistics. The use of component meta-data for target analysis, together with standards-based implementation strategies, ensures the complete portability of the instrumentation solution across different application servers. Based on this instrumentation infrastructure, a complete performance management framework including modelling and performance prediction is proposed. Most instrumentation solutions exhibit static behaviour by targeting a specified set of components. For long running applications, a constant overhead profile is undesirable and typically, such a solution would only be used for the duration of a performance audit, sacrificing the benefits of constantly observing a production system in favour of a reduced performance impact. This is addressed in this thesis by proposing an adaptive approach to monitoring which uses execution models to target profiling operations dynamically on components that exhibit performance degradation; this ensures a negligible overhead when the target application performs as expected and a minimum impact when certain components under-perform. Experimental results obtained with the prototype tool demonstrate the feasibility of the approach in terms of induced overhead. The portable and extensible architecture yields a versatile and adaptive basic instrumentation facility for a variety of potential applications that need a flexible solution for monitoring long running enterprise applications

Autonomous Recovery in Componentized Internet Applications

In this paper we show how to reduce downtime of J2EE applications by rapidly and automatically recovering from transient and intermittent software failures, without requiring application modifications. Our prototype combines three application-agnostic techniques: macroanalysis for fault detection and localization, microrebooting for rapid recovery, and external management of recovery actions. The individual techniques are autonomous and work across a wide range of componentized Internet applications, making them well-suited to the rapidly changing software of Internet services. The proposed framework has been integrated with JBoss, an open-source J2EE application server. Our prototype provides an execution platform that can automatically recover J2EE applications within seconds of the manifestation of a fault. Our system can provide a subset of a system's active end users with the illusion of continuous uptime, in spite of failures occurring behind the scenes, even when there is no functional redundancy in the system

A Uniform Programming Abstraction for Effecting Autonomic Adaptations onto Software Systems

Most general-purpose work towards autonomic or self-managing systems has emphasized the front end of the feedback control loop, with some also concerned with controlling the back end enactment of runtime adaptations but usually employing an effector technology peculiar to one type of target system. While completely generic 'one size fits all' effector technologies seem implausible, we propose a general-purpose programming model and interaction layer that abstracts away from the peculiarities of target-specific effectors, enabling a uniform approach to controlling and coordinating the low-level execution of reconfigurations, repairs, micro-reboots, etc

A Uniform Programming Abstraction for Effecting Autonomic Adaptations onto Software Systems

Most general-purpose work towards autonomic or self-managing systems has emphasized the front end of the feedback control loop, with some also concerned with controlling the back end enactment of runtime adaptations -- but usually employing an effector technology peculiar to one type of target system. While completely generic "one size fits all" effector technologies seem implausible, we propose a general purpose programming model and interaction layer that abstracts away from the peculiarities of target specific effectors,enabling a uniform approach to controlling and coordinating the low-level execution of reconfigurations, repairs,micro-reboots, etc

A Policy-Based Resource Brokering Environment for Computational Grids

With the advances in networking infrastructure in general, and the Internet in particular, we can build grid environments that allow users to utilize a diverse set of distributed and heterogeneous resources. Since the focus of such environments is the efficient usage of the underlying resources, a critical component is the resource brokering environment that mediates the discovery, access and usage of these resources. With the consumer\u27s constraints, provider\u27s rules, distributed heterogeneous resources and the large number of scheduling choices, the resource brokering environment needs to decide where to place the user\u27s jobs and when to start their execution in a way that yields the best performance for the user and the best utilization for the resource provider. As brokering and scheduling are very complicated tasks, most current resource brokering environments are either specific to a particular grid environment or have limited features. This makes them unsuitable for large applications with heterogeneous requirements. In addition, most of these resource brokering environments lack flexibility. Policies at the resource-, application-, and system-levels cannot be specified and enforced to provide commitment to the guaranteed level of allocation that can help in attracting grid users and contribute to establishing credibility for existing grid environments. In this thesis, we propose and prototype a flexible and extensible Policy-based Resource Brokering Environment (PROBE) that can be utilized by various grid systems. In designing PROBE, we follow a policy-based approach that provides PROBE with the intelligence to not only match the user\u27s request with the right set of resources, but also to assure the guaranteed level of the allocation. PROBE looks at the task allocation as a Service Level Agreement (SLA) that needs to be enforced between the resource provider and the resource consumer. The policy-based framework is useful in a typical grid environment where resources, most of the time, are not dedicated. In implementing PROBE, we have utilized a layered architecture and façade design patterns. These along with the well-defined API, make the framework independent of any architecture and allow for the incorporation of different types of scheduling algorithms, applications and platform adaptors as the underlying environment requires. We have utilized XML as a base for all the specification needs. This provides a flexible mechanism to specify the heterogeneous resources and user\u27s requests along with their allocation constraints. We have developed XML-based specifications by which high-level internal structures of resources, jobs and policies can be specified. This provides interoperability in which a grid system can utilize PROBE to discover and use resources controlled by other grid systems. We have implemented a prototype of PROBE to demonstrate its feasibility. We also describe a test bed environment and the evaluation experiments that we have conducted to demonstrate the usefulness and effectiveness of our approach

When Is an Enterprise Service Bus (Esb) the Right Choice for an Integrated Technology Solution?

The Enterprise Service Bus (ESB) is an important systems integration technology often closely associated with Service Oriented Architecture (SOA). Some maintain that an ESB should not be used apart from SOA. Others see the ESB simply as the next generation of middleware, incorporating the best of its predecessors, Enterprise Application Integration (EAI) and Message Oriented Middleware (MOM), and a candidate for any integration requirement. Is the ESB a one-size-fits-all solution to be trusted for any integration requirement, or must its use be carefully considered with proper due diligence based on application complexity and/or the presence or absence of a defined SOA? This thesis probes these questions in an analysis of a world-wide survey of 230 industry SOA and middleware professionals conducted via the LinkedIn Professional Network during a six week period in November and December of 2010. In addition, the thesis applies a review of the survey results and current SOA and ESB literature to an architectural decision being made within the Systems Engineering and Application Development (SEAD) Practicum in the Master of Science program in Computer Information Systems at Regis University in Denver, which provides support for the University\u27s Academic Research Network (ARN). An ESB has been proposed as a new architectural component for the ARN infrastructure and this paper reviews the merit of this proposal. This thesis employs an interpretivist epistemology, understanding that there may be more than one acceptable answer to the question, When is an Enterprise Service Bus an appropriate component of an integrated technology solution