Hitting the Turbo Button: Upgrading to PHP 7 at Etsy

PHP 7 offers fantastic resources to developers, trims memory consumption substantially, and can significantly reduce the CPU usage your software requires–often with few changes to your code. For those looking to migrate to PHP 7 or unsure of best practices to incorporate into your upgrade, you’ll learn about a battle tested design for deployment at scale. In this talk, I’ll discuss how Etsy designed a core upgrade to the site and how that might be applicable to companies of all sizes. Discussions will include how we chose between Hack/HHVM and PHP 7 and some of the tools built along the way, such as Phan, an open source static analyzer. This will also include an in depth review of how we deployed the upgrade, detailing some of the bumps in the process. Attendees should come away with a strong foundation of how the next phase of PHP can drastically improve performance and add powerful new features to aid in development.

Transcript

1. 1
   Hitting the Turbo Button: Upgrading to PHP 7 at Etsy @wcgallego
2. 2 Hey, I’m Will! Ops Engineer @ Etsy @wcgallego
3. 3 @wcgallego
4. 4
   Roadmap •Brief history of PHP 5 point release upgrades at Etsy •Our use of HHVM •Deciding between Hack/HHVM vs. PHP 7 •Deployment of PHP 7 •Wins, pitfalls, and features in PHP 7 @wcgallego
5. 5 #VU
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6. 6 PHP @ Etsy Timeline @wcgallego Prehistory 2012 2013 2014 2015 … 2012 …to 5.3 PHP 5.2 2013 …to 5.4 2014 …to 5.5 2015 …5.6?
7. Reworking our API Architecture @wcgallego
8. 8 @wcgallego Webs Browser DBs Previous Approach
9. 9 @wcgallego Webs Browser Internal API (multicurl) API Node API Node API Node API First Approach DBs
10. 10 @wcgallego Rising API Requests
11. HHVM to the rescue! @wcgallego
12. 12 @wcgallego
13. 13 @wcgallego
14. 14 @wcgallego
15. 15 PHP @ Etsy Timeline @wcgallego Spring
 2015 Summer
 2015 Fall
 2015 January
 2016 February
 2016 Summer
 2016 Early PHP 7 Testing/Benchmarks
16. 16 https://wiki.php.net/rfc/php6 “Version 6 is generally associated with failure in the world of dynamic language” @wcgallego Wait…what happened to PHP 6?
17. 17 PHP @ Etsy Timeline @wcgallego Spring
 2015 Summer
 2015 Fall
 2015 January
 2016 February
 2016 Summer
 2016 Porting Etsy Extensions to PHP 7
18. 18 https://bugs.php.net/bug.php?id=72396 @wcgallego https://php-lxr.adamharvey.name/source/ http://lxr.php.net/
19. 19
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20. 20 http://talks.php.net/velocity15#/wpbench http://hhvm.com/blog/9293/lockdown-results-and-hhvm-performance https://kinsta.com/blog/the-definitive-php-7-final-version-hhvm- benchmark/ @wcgallego
21. 21 Hack/HHVM @wcgallego Cons •More experiential knowledge with
 PHP/mod_php than Hack/HHVM/ fastcgi •Debugging multithreaded extensions •Different environment than Facebook: multi-curl in API at Etsy vs. async at Facebook •HHVM deploy shorter, but Hack everywhere a multiyear project Pros •Async (cooperative multitasking) •Generics •Collections (Vectors, Maps, Sets, Pairs) •Tuples, Enums, Shapes •compile time features like void return
22. 22 PHP 7 @wcgallego Cons •Need to write our own static analyzer •Core not yet prod ready •Extensions hadn’t seen wide internal testing like core •Some type features Hack has not in PHP Pros •All of our editors supported PHP 7 - vim, emacs, sublime text, phpstorm, etc. •Unsure direction Facebook takes Hack •Maintain current understanding of how our site runs •Shorter migration •Rasmus
23. 23 PHP @ Etsy Timeline @wcgallego Spring
 2015 Summer
 2015 Fall
 2015 January
 2016 February
 2016 Summer
 2016 Decision to deploy PHP 7
24. 24 4 2 1 3 Staging Fix Tests 100% Dev Compatible with PHP 5 and PHP 7 code, still running PHP 5 Test PHP 7 running in safe environment Prevent introduction of PHP 7 code to PHP 5 boxes PHP 7 Deployment Plan Production Slow introduction to pools, careful eye on perf and errors @wcgallego
25. 25 PHPUnit
 Upgrade before you start! @wcgallego
26. 26 PHPUnit Tests: 17815 Assertions: 61346 Errors: 66 Failures: 120 https://github.com/krakjoe/uopz @wcgallego
27. 27 Phan https://github.com/etsy/phan @wcgallego
28. 28
    Tee-ing Requests @wcgallego
29. 29 https://github.com/buger/gor @wcgallego
30. 30 PHP @ Etsy Timeline @wcgallego Spring
 2015 Summer
 2015 Fall
 2015 January
 2016 February
 2016 Summer
 2016 Single web node running PHP 7
31. 31 PHP @ Etsy Timeline @wcgallego Spring
 2015 Summer
 2015 Fall
 2015 January
 2016 February
 2016 Summer
 2016 PHP 7 deployed to all web nodes 
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33. 33
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34. 34 PHP @ Etsy Timeline @wcgallego Spring
 2015 Summer
 2015 Fall
 2015 January
 2016 February
 2016 Summer
 2016 Deployed to Dev VMs PHP 7 everywhere!
35. 35 Perf wins! @wcgallego
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    1BSTJOH 43 @wcgallego $class->$foo['bar'](); In PHP 5 that is interpreted as: $class->($foo['bar'])() while in PHP 7 it is: ($class->$foo)['bar']() It is easy enough to fix by adding curlies: $class->{$foo[‘bar']}()
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    1BSTJOH 44 @wcgallego $class->$foo['bar'](); In PHP 5 that is interpreted as: $class->($foo['bar'])() while in PHP 7 it is: ($class->$foo)['bar']() It is easy enough to fix by adding curlies: $class->{$foo[‘bar']}()
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    1BSTJOH 45 @wcgallego $class->$foo['bar'](); In PHP 5 that is interpreted as: $class->($foo['bar'])() while in PHP 7 it is: ($class->$foo)['bar']() It is easy enough to fix by adding curlies: $class->{$foo[‘bar']}()
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    1BSTJOH 46 @wcgallego $class->$foo['bar'](); In PHP 5 that is interpreted as: $class->($foo['bar'])() while in PHP 7 it is: ($class->$foo)['bar']() It is easy enough to fix by adding curlies: $class->{$foo[‘bar']}()
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    4PSUJOH <?php $foo = [ "a" => 1, "b" => 1 ]; asort($foo); print_r($foo); 49 @wcgallego PHP 5: Array ( [b] => 1 [a] => 1 ) PHP 7: Array ( [a] => 1 [b] => 1 )
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    &SSPST 50 @wcgallego <?php // PHP 5 era code that will break. function handler(Exception $e) { ... } set_exception_handler('handler'); // PHP 5 and 7 compatible. function handler($e) { ... } // PHP 7 only. function handler(Throwable $e) { ... }
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    'VODUJPOT 51 @wcgallego mysql_* -> mysqli_* For example:
 mysql_connect() should now be mysqli_connect() or used PDO class Legacy extension: https://github.com/php/pecl-database-mysql
52. 52 0UIFS
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    DIBOHFT http://php.net/manual/en/migration70.incompatible.php http://php.net/manual/en/migration70.deprecated.php @wcgallego
53. 53 &YUFOTJPOT @wcgallego • gearman • msgpack • oauth • memcached • gmagick •…a dozen more!
54. 54 SOAP ’n Certs PHP 7 is stricter about cert comparisons @wcgallego
55. 55 SOAP ’n Certs 1. Disable WSDL cache
 (http://lornajane.net/posts/2015/soapfault-when-switching-php-versions) 2. Update your certs! 3. use FQDN instead of IPs 4.* Could also turn off peer verification (but probably not advisable) @wcgallego
56. 56 /6." @wcgallego
57. 57 On NUMA @wcgallego
58. 58 But enough of the doom and gloom... @wcgallego
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60. 60 .PSF
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    &UTZ • File backed opcache - cli speed up, avoid thundering herd on graceful restarts • Better compilation! Latest GCC, ICC, etc. • FDO (Feedback Directed Optimization) as part of GCC > 5 • Tuning to avoid filling up opcache as often 61 @wcgallego
62. 1BSUJOH
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63. 63 5IBOLT @wcgallego https://joind.in/talk/41de3
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