A Quality of Service Approach to Survivability
Abstract
The scope of the project includes creating an interface definition language for Quality of Service (QoS) in support of end-to-end composibility and metrics/models and instrumentation for QoS. A design for providing varying degrees of redundancy in an object-oriented distributed system has been completed. Application programmer can specify both a degree of redundancy and the degree of consistency/synchronization among the redundant copies of a resource. The Adaptive Quality of Service Availability (AQuA) project had the objective of controlling the availability of application services in the common Object Request Broker Architecture (CORBA). The project focused primarily on the problem of crash failures, an secondarily on other failures that would cause untimely or incorrect replies to be received by clients. Under these circumstances, AQuA controls the availability of CORBA services by replicating servers, that is, by providing multiple, essentially identical copies of the server operating on different hosts. In this way, the failure of any one copy of the server or of it host tends to be masked by the correct operation of other copies of the server. The AQuA project demonstrated how a distributed system could provide dependability of service. The AQuA release provides dependability of objects (clients as well as servers) by means of replication of the objects. The provision of dependability is highly controllable and adaptable at run time.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 2000
- Accession Number
- ADA382571
Entities
People
- David A. Karr
- David E. Bakken
- John A. Zinky
- Mark Berman
- Richard Schantz
Organizations
- BBN Technologies