Orphan Detection in the Argus System.
Abstract
In a distributed system, an activity running at one node can request another node to perform some service. This request results in an activity being created at the latter node to perform the requested service. The former node may then crash, destroying the activity that requested the service, but leaving behind the activity performing the service. Such surviving activities are known as orphans. Orphans are undesirable since they waste resources and can view inconsistant data. This thesis presents an algorithm that detects and exterminates orphans before they can view inconsistant data. The algorithm has the desirable property that no non-orphans are mistakenly identified as orphans and exterminated. An underlying premise of the algorithm is that orphan detection and extermination should delay normal computation as little as possible. The algorithm works by piggybacking information concerning orphans on various messages that flow about the system. The algorithm piggybacks an impractical amount of data on messages. The main contribution of this thesis is the development of a method called deadlining. This method works in conjunction with the algorithm to detect orphans before they view inconsistant data, while substantially reducing the amount of data piggybacked on messages. An analytic model is used to predict the actual performance of the deadlining. Originator-supplied keywords include: Atomic actions, Orphans, Distributed systems, Remote procedure call.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1984
- Accession Number
- ADA150562
Entities
People
- E. F. Walker
Organizations
- Massachusetts Institute of Technology