Anna Kobusińska

D-reserve: distributed reliable service environment

Nowadays, a major paradigm of large scale distributed processing is service-oriented computing. To improve the availability and reliability of the SOA-based systems and applications, a Reliable Service Environment ReServE, providing an external support of web services recovery, has been proposed. The functionality of ReServE can be enhanced by distributing its architecture. However, this causes several problems, which have to be solved. In this paper we address these problems and propose their solution.

ReServE service: an approach to increase reliability in service oriented systems

Heterogeneous environment of service-oriented computing turns to be very error-prone, due to the loose-coupling and a great number of independent components that are susceptible to failures. Therefore, we propose the ReServE service, which improves the reliability of the SOA-based systems and applications. The proposed service ensures that after a failure occurrence, the state of a business process is transparently recovered, and it is consistently perceived by the business process participants: clients and web services.

Version vector protocols implementing session guarantees

This paper analyses different protocols of session guarantees. Session guarantees (also known as client-centric consistency models) are one of the class of consistency models of replicated shared data, besides data-centric consistency models. The presentations comprises details of the data structures for the information maintained locally and passed to check consistency conditions, as well as the algorithms to process the information. The protocols are also discussed with respect to accuracy and data overhead.

FAST Failure Detection Service for Large Scale Distributed Systems

This paper addresses the problem of building a failure detection service for large scale distributed systems. We describe failure detection service, which merges some novel proposals and satisfies scalability, flexibility and adaptability properties. Afterwards, we present the architecture of such a service, show detailed information about its components and present the simulation results concerning performance.

Applying message logging to support fault-tolerance of SOA systems

Abstract This paper addresses a problem of increasing fault-tolerance of serviceoriented systems built of RESTful web services. To solve such a problem, rollbackrecovery protocol is proposed. The protocol employs known rollback-recovery techniques, however, it modifies and specially adjusts them for specific characteristics of the SOA systems. The paper includes a proof of safety property of the proposed protocol.

ROsWeL Workflow Language: A Declarative, Resource-oriented Approach

Well defined business processes are a crucial success factor for deploying SOA/SOKU architectures. In this paper, the declarative business process description language—ROsWeL—which supports applications compatible with ROA, is discussed. ROsWeL provides a declarative, reliable and semi-automatic composition of RESTful web services, enriched by the knowledge representation. The paper discusses benefits of ROsWeL, and presents an example of a simple workow that captures essential ROsWeL features.

Dependability Infrastructure for SOA Applications

This chapter describes two tools for improving dependability of SOA-based applications: ReSP (Reliable SOA Platform) and DyMST (Dynamic Management SOA Toolkit). ReSP is a set of modules to improve dependability in respect to availability and reliability, and to some extent safety. It is comprised of the mechanisms of reliable group communication, replication, recovery, and transaction processing. DyMST is a set of components for failure detection, monitoring and autonomic management, and distributed security policy enforcement. In order to show the dependability aspects of real applications and usage of these tools, two case studies from the medical healthcare domain are presented: Healthcare Integration Platform for the exchange of patients’ medical data among various healthcare units, and Medical Event, and Data Registering Platform for daily work improvement of medical staff.

The Impact of Service Semantics on the Consistent Recovery in SOA

This paper addresses a problem of consistent recovery of SOA processing. So far, the recovered state was considered as consistent if all events that have occurred before the failure were transparently recovered. However, providing such a strict consistency introduces a high performance overhead. Thus, we propose the semantic-based classification of services that enables to slack the notion of consistent recovered state from the viewpoint of services. We also present the extension of RESERVE rollback-recovery protocol that guarantees the proposed relaxed recovery consistency.

Mobile Edge Computing

A wireless network device can receive, at a traffic director in a kernel space, a data packet from a client device and determine whether the data packet is intended for an application cloud server operating in a cloud environment. The wireless network device can provide, based on determining that the data packet is intended for the application cloud server, the data packet to an application server instance executing on the wireless network device. The application server instance can be implemented in a virtualized software container in a user space, and can be configured to perform one or more operations associated with the application cloud server. The wireless network device can receive, at the traffic director and from the application server instance, a result of the application server instance performing the one or more operations on the data packet, and transmit the result to the application cloud server.

A branch hash function as a method of message synchronization in anonymous P2P conversations

Abstract Currently existing solutions rarely protect message integrity, authenticity and user anonymity without burdening the user with details of key management. To address this problem, we present Aldeon-a protocol for anonymous group conversations in a peer-to-peer system. The efficiency of Aldeon is based on a novel tree synchronization algorithm, which is proposed and discussed in this paper. By using this algorithm, a significant reduction in the number of exchanged messages is achieved. In the paper, the formal definition of the proposed hash branch function and the proof of its efficiency are presented.