Distributed platform support for service management
Distributed computing systems, with a high degree of interaction, cooperation, and sharing of resources between large numbers of computing elements, are becoming critical to the working of many enterprises. The evolution of services and networks along with the development of interorganisational, distributed applications require distributed management techniques, systems and tools. Different platforms are currently available to assist the development of distributed applications, hiding the underlying diversity and physical distribution of different computers, operating systems and network protocols. However, they supply neither facilities for automatic management of the support services they provide to application developers nor of the applications themselves. A random allocation of software components to nodes and the lack of resource management policies may lead to poor performance by having some nodes overloaded while others are idle. This thesis proposes an approach to distributed systems management, addressing in particular the distribution of the workload submitted to a distributed system by its users. A management architecture based on the ODP Reference Model and the OSI Management Model is presented. Distributed System managers, each responsible for a management domain, and Node Managers interact to allocate services to suitable nodes, considering the services requirements and the resources available. A prototype implementation is described which demonstrates how the concepts and mechanisms that form the architecture can be realised. This, together with a qualitative evaluation, shows the benefits of incorporating this management approach in a distributed environment: service creation and distribution, as well as resource management, is made transparent to platform users; the workload submitted to the system is automatically distributed; and services are provided with the requirements they need.