The Why and How of moving to PHP 5.5/5.6

Who am I ?

Wim Godden (@wimgtr)

Founder of Cu.be Solutions (http://cu.be)

Open Source developer since 1997

Developer of OpenX, PHPCompatibility, PHPConsistent, ...

Speaker at Open Source conferences

Why vs How

Part 1 : why upgrade ?Bad reasons :

It's cool to have the latest version

Annoy sysadmins

Oh cool, a new toy !

Part 2 : how to upgrade ?The nightmare of compatibility

The joy of automation

No miracles here !

Show of hands

3 / 4

5.0

5.1

5.2

5.3

5.4

5.5

5.6

6.0

7.0

The numbers

W3Techs (http://w3techs.com/technologies/details/pl-php/all/all)

Now Nov 2013 Aug 2013 May 2013

PHP 4 : 1.8% 2.7% 2.9% 2.7%

PHP 5 : 98.2% 97.3% 97.1% 97.3%

5.0 : < 0.1% 0.1% 0.1% 0.1%

5.1 : 1.2% 2.0% 2.2% 2.6%

5.2 : 19.2% 37.6% 40.2% 43.5%

5.3 : 45.5% 52.0% 51.7% 49.7%

5.4 : 26.9% 7.9% 5.7% 4.1%

5.5 : 6.3% 0.5% 0.1 % < 0.1%

5.6 : 0.5% < 0.1%

5.7 : < 0.1%

5.27 : < 0.1%

5.3 quick recap

Namespaces (\)

Late static binding

Closures

Better garbage collection

Goto

Mysqlnd

Performance gain

5.4 quick recap

Short array syntax

Function array dereferencing

Traits

Built-in webserver

SessionHandler

File upload extension

Binary notation

register_globals and magic_quotes_gpc removed :-)

Safe mode removed :-)

5.3 – people are not even using it !

19.2% still on PHP 5.2

No :Symfony 2

Zend Framework 2

Other frameworks that need namespaces

Problematic for developers

PHP 5.5/5.6 – what's changed ?

New features

Performance and memory usage

Improved consistency

Some things removed

New things – Generators (5.5)

Simple way of implementing iterators

Simply put : foreach over a functionSay what ?

Generators - example

<?phpfunction returnAsciiTable($start, $end) { for ($i = $start; $i <= $end; $i++) { yield $i => chr($i); }}

foreach (returnAsciiTable(97, 122) as $key => $value) { echo $key . " - " . $value . "\n";}

Output :97 - a98 - b99 - c100 - d101 - e102 - f103 - g104 - h105 - i106 - j107 - k108 - l109 - m110 - n111 - o112 - p113 - q114 - r115 - s116 - t117 - u118 - v119 - w120 - x121 - y122 - z

Finally : finally (5.5)

Exception handling

Until now : try {} catch() {}

Now :

<?phptry { doSomething();} catch (Exception $e) { echo 'Caught exception: ', $e->getMessage(), "\n";} finally { echo "We're always going here !";}

Beware : finally + return

<?php

function footest(){ try { return 1; } catch (Exception $e) { return 2; } finally { return 10; }}

echo footest();

Will return 10 !

Password hashing (5.5)

To create :$hash = password_hash($password, PASSWORD_DEFAULT);

To verify :password_verify($password, $hash);

Currently only supports Blowfish

Also has password_needs_rehash() → check if hash was strong enough

Zend Optimizer+ (5.5)

Name in PHP 5.5 : OPcache

Opcode cache (like APC, Xcache, ...)

APC users : no userland (variable) caching in OPcache→ Use APCu

Variadic functions

function sumNumbers($base, ...$params) { foreach ($params as $param) { $base += $param; } return $base;}

sumNumbers(5); // returns 5sumNumbers(5, 2); // returns 7sumNumbers(5, 2, 3); // returns 10

Argument unpacking

function add($a, $b, $c) { return $a + $b + $c;}

$params = array(2, 3);echo add(5, ...$params); // returns 10

Other changes in 5.6

json_decode() strictness : true, false, null values

Constant expressions :const ONE = 1;

const TWO = ONE * 2;

Exponent operator (**)printf("2 ** 4 == %d\n", 2 ** 4);

→ Output = 2 ** 4 == 16

use function and use const

Default charset is now UTF-8 → set in ini default_charset

__debuginfo() magic method for use with var_dump()

SSL/TLS security improvements (peer certificate verification, TLS renegotiation attacks, …)

phpdbg : interactive debugger

Removed features in PHP 5.5

php_logo_guid()

php_egg_logo_guid()

php_real_logo_guid()

zend_logo_guid()

Windows XP and 2003 support

Removed features in PHP 5.6

$HTTP_RAW_POST_DATA and ini setting always_populate_raw_post_data

iconv and mbstring encoding settings → default_charset in ini

Performance and memory usage from 5.3 to 5.6

Performance : 10 – 30%How ?

Core optimizations

New internal caches (functions, constants, …)

Better (un)serialization

Inlining often-used code paths

…

Reduced memory usage : up to 50% !Big impact on large frameworks

Even bigger impact on codebases such as Drupal

So...

Should you upgrade today ?

Upgrade : yes / no

Yes No

Using removed extensions x

Using removed functions x

Need extra performance / reduced memory x

Really need new feature x

Want to use recent framework x

No unit tests x

No package available (.rpm, .deb, ...) x

Postponing upgrades

End-Of-LifeIn the past : we'll see

Now : minor release + 2 = out → EOL

5.5 = OUT → 5.3 = EOL

5.6 = OUT → 5.4 = EOL

Critical security patches : 1 year

No bugfixes

Framework support

Developer motivation

So you want to upgrade...

Option 1 : run your unit tests

Option 2 : visit each page (good luck !) + check error_logOr : record visits, then replay log on test environment

Option 3 : automated static analysis

Unit tests on different PHP versions

Vagrant boxes

Integrate into your CI

Use Travis CI (http://travis-ci.org)

Why make it so hard ? A best-case scenario...

Development environment : 5.6

Production environment : 5.6

All is well, right ?

End 2015 : PHP 7 arrives

How can you test compatibility ?

→ Set up your test environment today

→ Even for new projects

Back in 2010...

PHP Architect @ Belgian Railways

8 years of legacy code

40+ different developers

40+ projects

Challenge :

migrate all projects from

PHP 5.1.x (on Solaris)

to

PHP 5.3.x (on Linux)

The idea

Automate it

How ? → Use the CI environment

Which tool ? → PHP_CodeSniffer

PHP_CodeSniffer

PEAR package (pear install PHP_CodeSniffer)

Detect coding standard violations

Supports multiple standards

Static analysis tool→ Runs without executing code

→ Splits code in tokens

Ex. : T_OPEN_CURLY_BRACKET

T_FALSE

T_SEMICOLON

PHP_CodeSniffer

Let's see what it looks like

PHPCompatibility

New PHP_CodeSniffer standard

Only purpose : find compatibility issues

Detects :Deprecated functions

Deprecated extensions

Deprecated php.ini settings and ini_set() calls

Prohibited function names, class names, …

…

Works for PHP 5.0 and above

PHPCompatibility – making it work

Via Composer : wimg/php-compatibility

From Github :Download :

http://github.com/wimg/PHPCompatibility

Install in <pear_dir>/PHP/CodeSniffer/Standards

Run :phpcs --standard=PHPCompatibility <path>

PHPCompatibility

Let's see what it looks like

Important notes

Large directories → can be slow !

Use --extensions=php,phtmlNo point scanning .js files

Static analysisDoesn't run code

Can not detect every single incompatibility

Provides filename and line number

The result

Zend Framework 1.7 appPHP 5.2 : working fine

PHP 5.3 : fail !

function goto()

Some common apps – phpBB (latest)

FILE: /usr/src/phpBB3/adm/index.php--------------------------------------------------------------------------------FOUND 0 ERROR(S) AND 2 WARNING(S) AFFECTING 1 LINE(S)-------------------------------------------------------------------------------- 48 | WARNING | INI directive 'safe_mode' is deprecated in PHP 5.3 and forbidden in PHP 5.4. 48 | WARNING | INI directive 'safe_mode' is deprecated in PHP 5.3 and forbidden in PHP 5.4.--------------------------------------------------------------------------------

Common apps - MediaWiki

FILE: /usr/src/mediawiki-1.19.8/includes/GlobalFunctions.php--------------------------------------------------------------------------------FOUND 0 ERROR(S) AND 1 WARNING(S) AFFECTING 1 LINE(S)-------------------------------------------------------------------------------- 2705 | WARNING | The use of function dl is discouraged in PHP version 5.3 and | | discouraged in PHP version 5.4 and discouraged in PHP version | | 5.5--------------------------------------------------------------------------------

Common apps – Wordpress (latest)

FILE: /usr/src/wordpress/wp-admin/includes/class-pclzip.php--------------------------------------------------------------------------------FOUND 2 ERROR(S) AFFECTING 2 LINE(S)-------------------------------------------------------------------------------- 5340 | ERROR | The use of function set_magic_quotes_runtime is discouraged in | | PHP version 5.3 and forbidden in PHP version 5.4 and forbidden | | in PHP version 5.5 5371 | ERROR | The use of function set_magic_quotes_runtime is discouraged in | | PHP version 5.3 and forbidden in PHP version 5.4 and forbidden | | in PHP version 5.5--------------------------------------------------------------------------------

FILE: /usr/src/wordpress/wp-includes/SimplePie/Item.php--------------------------------------------------------------------------------FOUND 0 ERROR(S) AND 1 WARNING(S) AFFECTING 1 LINE(S)-------------------------------------------------------------------------------- 125 | WARNING | INI directive 'zend.ze1_compatibility_mode' is deprecated in | | PHP 5.3 and forbidden in PHP 5.4.--------------------------------------------------------------------------------

FILE: /usr/src/wordpress/wp-includes/wp-db.php--------------------------------------------------------------------------------FOUND 16 ERROR(S) AFFECTING 16 LINE(S)-------------------------------------------------------------------------------- 641 | ERROR | Extension 'mysql_' is deprecated since PHP 5.5 - use mysqli | | instead. 646 | ERROR | Extension 'mysql_' is deprecated since PHP 5.5 - use mysqli | | instead.

Conclusion

No 100% detection

But : 95% automation = lots of time saved !

First : PHPCompatibility on local machine

Then : use your CI/test environment and run unit tests

Start upgrading !

Questions ?

Questions ?

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Thanks !

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