Fail-Silent Hardware for Distributed Systems

  • David Powell
Part of the Research Reports ESPRIT book series (ESPRIT, volume 1)


The architectural frameworks assumed in this chapter are those of OSA and XPA, and are summarised below:
  1. a)

    distributed computations are assumed to be structured as software components communicating via messages;

  2. b)

    XPA: software components execute on fail-controlled nodes with the fail-silent property: a node either functions according to the specification or stops functioning;

    OSA: the fail-silent property is not essential for nodes, so software components can execute on ordinary (potentially) fail-uncontrolled nodes; however, all the protocols for message passing are executed on fail-silent hardware (the Network Attachment Controllers, NACs);

  3. c)

    nodes communicate with each other through redundant communication networks;

  4. d)

    software components can be replicated on distinct nodes for increased reliability; the degree of replication (if any) for a software component will be determined by the failure characteristic of the underlying nodes: K+1 replicas can tolerate up to K replica failures if the nodes are assumed to be fail-silent, whilst 3K+1 replicas are needed if the nodes are assumed to be fail-uncontrolled.



Network Interface Clock Synchronization Priority Message Valid Message Processor Pair 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© ECSC — EEC — EAEC, Brussels — Luxembourg 1991

Authors and Affiliations

  • David Powell
    • 1
  1. 1.LAAS-CNRSToulouseFrance

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