Upgrading from PHP 5.3 to 5.5

A small talk on the experiences gained from migrating from PHP 5.3 to 5.5.

Transcript

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2. Glen Mailer
   

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3. The Codebase
   

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4. First commit April 2010

   60k commits since
   

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5. 9300 PHP files

   690k lines of code
   According to git and cloc
   

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6. 10 releases a week

   35 active committers

   10 concurrent streams

   1 deployable
   

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7. The Platform
   

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8. 8 Test Environments

   1 Staging Environment

   2 Live Environments
   

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9. 74 Live PHP boxes
   

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10. 1300 req/s peak

    500k uniques/week
    

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11. Why?
    

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12. Using basically the same
    PHP version as the first
    commit
    with security patches
    

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13. PHP 5.3 is dead
    

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14. Bug fixes

    Performance
    

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15. New Features!
    short array syntax
    traits
    $this in closures
    yield
    finally
    

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16. but no smoking gun
    

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17. Bug #64827

    GC causes segfaults
    

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18. The Plan
    

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19. Upgrade a dev box

    Support 5.3 and 5.5

    Pass all tests

    Upgrade 1 Test env

    Upgrade CI

    Upgrade Test & Staging

    Incrementally Upgrade Live
    

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20. Vagrant

    Chef

    Unit Tests

    Acceptance Tests
    

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21. Hack hack hack...
    

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22. 3 days later
    

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23. What changed?
    

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24. APC

    becomes

    OPcache and APCu
    

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25. Check for new function, fall back to old one
    if (function_exists('opcache_reset')) {
    opcache_reset();
    } else {
    apc_clear_cache();
    }
    

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26. “The PHP api will retain
    compatibility with APC, as
    will common configuration
    options, providing a drop
    in replacement.”
    APCu
    

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27. Not a drop in replacement
    

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28. APCu 4.0.1

    APCu 4.0.2
    

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29. No more

    mysql_
    

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30. It will not be missed
    

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31. preg_replace /e

    becomes

    preg_replace_callback
    

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32. (string) array()

    Now raises a warning
    Still returns “Array”
    

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33. Type-checked function
    function inc($int) {
    if (!is_int($int)) {
    throw new InvalidArgumentException(
    'Expected int, got: ' . $int
    );
    }
    return $int + 1;
    }
    

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34. Unit test for type-checked function
    /**
    * @dataprovider provideIncInvalid
    */
    function testIncRejectsInvalid($a) {
    try {
    inc($a);
    $this->fail('Expected exception');
    } catch (InvalidArgumentException $ex) {}
    }
    function provideIncInvalid() {
    return array(
    null, true, "string", array()
    );
    }
    

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35. Simplest fix
    throw new InvalidArgumentException(
    'Expected int, got: ' .
    json_encode($int)
    );
    

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36. $a = "string”;

    $a['index'];

    Now raises a warning
    

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37. // protected $a;

    ++$this->a

    Now raises a warning
    

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38. Progress
    

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39. Upgrade a dev box

    Support 5.3 and 5.5

    Pass all tests

    Upgrade 1 Test env

    Upgrade CI

    Upgrade Test & Staging

    Incrementally Upgrade Live
    

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40. Upgrade a dev box

    Support 5.3 and 5.5

    Pass all tests

    Upgrade 1 Test env

    Upgrade CI

    Upgrade Test & Staging

    Incrementally Upgrade Live
    

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41. What now?
    

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42. Finish Migrating Live
    

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43. See if the hard to
    reproduce failures have
    stopped
    

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44. Start using new
    features!
    

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45. Keep up to date
    

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46. You should upgrade too!
    

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47. Fin.
    

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48. Questions?
    

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49. @glenathan
    
    https://joind.in/9473
    
    

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