[Beowulf] failure rates

[Bruno Rocha Coutinho]

Most fault-tolerance literature assume that system components have 
exponential failure rates.

But software sometimes don't have exponential failure rates if the cause 
of the failure is related to a timer, a overflow or resource leaks. In 
this case failure rate could be fixed and you end with all process 
failing at the same time.

I think that is safe to assume exponential failure rates for hardware 
and in spite of most machine crashes today are OS (not hardware) 
related, most people assume that OSs are well behaved and don't suffer 
of fixed rate failures.


2007/1/30, enver ever <enverever at hotmail.com>:

    Hello there

    I am a PhD student working on mathematical looking to the
    availability of
    Beowulf clusters.

    I was looking whether or not it is possible to take exponential failure
    rates fot the nodes.

    Thats the case in these publications:

    1- "A Realistic Evaluation of Consistency Algorithms for Replicated
    Files"Annual Simulation Symposium archive Proceedings of the 21st annual
    symposium on Simulation table of contents Tampa, Florida, United States
    Pages: 121 - 130 Year of Publication: 1988 ISBN:0-8186-0845-5

    2-"Availability Modeling and Analysis on High Performance
    ClusterComputing
    Systems"Availability, Reliability and Security, 2006. ARES 2006. The
    First
    International Conference on Publication Date: 20-22 April 2006

    3-"A Failure Predictive and Policy-Based High Availability Strategy for
    Linux High Performance Computing Cluster" Chokchai Leangsuksun1,
    Tong Liu1,
    Tirumala Rao1, Stephen L. Scott2, and Richard Libby Linux.com | LCI 5th
    International Linux Cluster Conference.

    I think it can be taken as exponentially distributed since in many
    multi-server systems this was the approach followed.

    I would appreciate if you could add any comments

    Many Regards

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