[eva] 5. detection patterns - patterns for fault tolerant software
DESCRIPTION
Pattern for Fault Tolerant Software Chapter 5. Detection Patterns OverviewTRANSCRIPT
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Pattern for Fault Tolerant Software
Chapter 5. Detection Patterns
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The first phase of fault tolerance is detection
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The dimensions of detection
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A Priori Detection
use constraints
System states, Result, Side effects
If nothing is known about the range of results this method will obviously not work.
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Comparing Redundant Results
Redundancy ( 3 , chapter 4)
The value to be compared or The context to enable the identification of the faulty component
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To learn about correct system behavior
ex) Bayesian learning technique
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Just determining that one is incorrect is helpful,
but insufficient to fix the fault andprevent a failure from occurring
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Detect an Error > Detect a failure
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The error is detected automatically and corrected before it becomes a failure
‘fail-silent’ and crash failure mode
element stops without informing them that it is stopping
detecting that an element has stopped functioning vsdetermining if an element has stopped operating correctly
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Test function return codes
try/catch
Detecting Errors
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Next - Fault Correlation