Systematic Debugging

Transcript

1. Systematic
   Debugging
   Obi Uchenna David
   
   
   @othreecodes
   
   
   

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2. Introduction & Overview
   Bugs
   Debugging
   Tracing
   Summary
   Profiling
   00
   Overview
   • Identifying a problem.
   
   
   • Isolating the source of the
   problem.
   
   
   • Correcting the problem or
   determining a way to work
   around it.
   
   
   • Testing to ensure its fixed.*
   

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3. Introduction & Overview
   01
   How they occur
   
   
   • Syntax errors
   
   
   • Runtime errors
   
   
   • Compilation errors
   
   
   • Logic/Semantic errors
   
   
   • Resource errors
   
   
   • Interface errors
   Bugs
   Debugging
   Tracing
   Summary
   Profiling
   

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4. Introduction & Overview
   02
   Syntax errors
   
   
   • Linters help
   
   
   • IDEs have made life easier
   Bugs
   Debugging
   Tracing
   Summary
   Profiling
   

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5. Introduction & Overview
   03
   Runtime and Compilation errors
   
   
   • Compilation errors occur at
   build time.
   
   
   • Runtime errors occur at
   execution point.
   
   
   • Sometimes it may be due to
   server config changes or
   missing environment
   variables.
   Bugs
   Debugging
   Tracing
   Summary
   Profiling
   

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6. Introduction & Overview
   04
   Logic and Semantic errors (and interface errors)
   
   
   • Program will run, but it won’t
   go anywhere
   
   
   • Understanding
   requirements are important
   
   
   • Interface errors happen
   when you use code other
   than its meant to be used.
   Bugs
   Debugging
   Tracing
   Summary
   Profiling
   

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8. Introduction & Overview
   06
   Debugging
   
   
   Debugging is at the core of
   programming, because it takes up the
   largest percentage of your time while
   coding.
   
   
   There are three major phases involved in
   debugging:
   
   
   1. Finding bugs.
   
   
   2. Analyzing and understanding why
   bugs occur.
   
   
   3. Fixing or removing bugs.
   Bugs
   Debugging
   Tracing
   Summary
   Profiling
   

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9. How I fix/remove bugs
   • Restart app/server
   
   
   • Check failing tests
   
   
   • Check logs
   
   
   • Use break points
   
   
   • Revert to last working
   code
   
   
   • Copy and paste stack
   trace on google
   07
   

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10. Story time…
    08
    

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11. 09
    How do you fix a bug you did not
    create?
    

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12. Introduction & Overview
    10
    Logging
    
    
    Bugs
    Debugging
    Tracing
    Summary
    Profiling
    A log is a record of events that happened over
    time.
    Log files can show any discrete event within an
    application or system, such as a failure, and
    error, or a state transformation. When
    something inevitably goes wrong, such
    transformations in state help indicate which
    change actually caused an error.
    

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13. Kibana Logs
    

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14. Introduction & Overview
    12
    Tracing
    
    
    Bugs
    Debugging
    Tracing
    Summary
    Profiling
    A trace is a log of events within the program
    often related to a single user.
    

    This log may be detailed enough to report
    function calls and returns, and execution of
    other statements.
    Traces can be used for discovering the chain of
    events that led to a problem
    The goal of tracing is to following a program’s
    flow and data progression.
    

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15. Firebase streamview
    

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16. Introduction & Overview
    14
    Tracing
    
    
    Bugs
    Debugging
    Tracing
    Summary
    Profiling
    Tracing acts like the blackbox of an aircraft
    during a crash: it helps you understand how
    things went during a crash, to discover the
    chain of events that led to a problem.
    
    
    It provides a low-level view to understand:
    
    
    • what triggered what in the program
    
    
    • with which arguments
    
    
    • in which order
    
    
    • how long did each step lasts
    
    
    

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17. Introduction & Overview
    15
    Distributed Tracing
    
    
    Bugs
    Debugging
    Tracing
    Summary
    Profiling
    Distributed tracing is a method of observing
    requests as they propagate through
    distributed cloud environments
    Distributed tracing follows an interaction by
    tagging it with a unique identifier, which stays
    with it as it interacts with microservices,
    containers, and infrastructure.
    Distributed tracing pinpoints the exact areas
    where issues lie.
    

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18. Distributed tracing architecture
    

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19. Introduction & Overview
    17
    Profiling
    
    
    Bugs
    Debugging
    Tracing
    Summary
    Profiling
    A profile provides an inventory of performance
    events and timings for the execution as a
    whole. This ignores the chronology of the
    events in an absolute sense.
    Profiling is a good way to discovering resource
    errors.
    Profiling and metrics are the last piece of the
    monitoring puzzle. Together, they provide a
    statistic overview of a system's health and
    tracked events over time.
    

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20. Introduction & Overview
    18
    Profiling
    
    
    Bugs
    Debugging
    Tracing
    Summary
    Profiling
    Profiles range from low-level metrics like CPU
    usage or file I/O to higher-level metrics like
    throughput or latency. When aggregated and
    seen together, they are powerful signals giving
    you a holistic view of your system and can help
    detect issues.
    

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21. Firebase performance monitoring
    

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22. Wed.dev performance metrics
    

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23. Newrelic profiling
    

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24. Omo
    

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25. Introduction & Overview
    Processes
    What makes it work
    In Practical
    Summary
    Challenges
    23
    Here’s what we know
    
    
    In Summary
    When used together, Logging,
    Tracing and Profiling can give you
    powerful insights about your
    services and systems: detecting
    anomalies when they arise and
    quickly understand the root cause
    of performance issues.
    

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26. References
    
    
    • http://wearepresta.com/a-systematic-approach-to-debugging/
    
    
    • https://www.freecodecamp.org/news/how-to-improve-your-
    debugging-skills/
    
    
    • https://searchsoftwarequality.techtarget.com/definition/debugging
    
    
    • https://www.bmc.com/blogs/monitoring-logging-tracing/
    
    
    • https://stackify.com/what-is-code-profiling/
    
    
    • https://developer.android.com/topic/performance/tracing
    
    
    • https://youtu.be/dmnA3axZ3FY
    
    
    • https://stackoverflow.com/questions/41725613/definition-of-
    debugging-profiling-and-tracing
    
    
    • https://www.jackkinsella.ie/articles/7-keys-to-systematic-debugging
    
    
    • https://www.debuggingbook.org/beta/html/Intro_Debugging.html
    
    
    • https://www.jwhitham.org/2016/02/profiling-versus-tracing.html
    
    
    • http://ipm-hpc.sourceforge.net/profilingvstracing.html
    
    
    

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27. References
    
    
    • https://greeeg.com/issues/differences-between-logging-tracing-
    profiling
    
    
    • https://www.dynatrace.com/news/blog/what-is-distributed-tracing/
    

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