Deploying PHP 7
Scotland PHP
Edinburgh
Oct.29, 2016
http://talks.php.net/scotphp16Rasmus Lerdorf
@rasmus
✔ engine improvements
- 100%+ performance gain on most real-world applications
- Lower memory usage, sometimes drastically lower
JIT?
Improve CPU cache usage
- Step 1: Decrease overall data
- Step 2: Better data locality and less indirections
- Step 3: Save the world!
- zval size reduced from 24 to 16 bytes
- Hashtable size reduced from 72 to 56 bytes
- Hashtable bucket size reduced from 72 to 32 bytes
- Immutable array optimization
$a = [];
for($i=0; $i < 100000;$i++) {
$a[] = ['abc','def','ghi','jkl','mno','pqr'];
}
echo memory_get_usage(true);
// PHP 5.x 109M
// PHP 7.0 42M no opcache
// PHP 7.0 6M with opcache enabled- New memory allocator similar to jemalloc
- Faster hashtable iteration API
- Array duplication optimization
- PCRE JIT enabled by default
- Precomputed string hashes
- Fast ZPP (ZendParseParameters) implementation
- Faster stack-allocated zvals (instead of heap)
- Optimized VM calling
- Global register variables with gcc 4.8+
- plus hundreds of micro-optimizations
JIT?
GCC Feedback-Directed Optimization (FDO)
$ make clean
$ make -j8 prof-gen
...
$ sapi/cgi/php-cgi -T 1000 /var/www/wordpress/index.php > /dev/null
$ make prof-clean
$ make -j8 prof-useHad to fix one line of code in the Avalon database library:
diff --git a/database/model.php b/database/model.php
index 6c5f7da..c93e726 100644
--- a/database/model.php
+++ b/database/model.php
@@ -397,7 +397,7 @@ public function __get($var) {
$belongs_to['column'] = $var . '_id';
}
$model = $belongs_to['model'];
- return $this->$var = $model::find($belongs_to['foreign_key'], $this->$belongs_to['column']);
+ return $this->$var = $model::find($belongs_to['foreign_key'], $this->{$belongs_to['column']});
} else {
$val = $this->$var;✔ engine improvements
- 100%+ performance gain on most real-world applications
- Lower memory usage, sometimes drastically lower
✔ Exceptions on Fatals
function call_method($obj) {
$obj->method();
}
call_method(null);Fatal error: Uncaught Error: Call to a member function method() on null in file:2
Stack trace:
#0 file(4): call_method(NULL)
#1 {main}
thrown in file on line 2try {
call_method(null);
} catch (Error $e) {
echo "Caught Exception: {$e->getMessage()}\n";
}Caught Exception: Call to a member function method() on nullPHP 7 Exception Hierarchy
- Throwable
- ➥ Exception implements Throwable
- ➥ Error implements Throwable
- ➥ TypeError extends Error
- ➥ ParseError extends Error
✔ Return Types
function get_config(): array {
return 42;
}
get_config();Fatal error: Uncaught TypeError: Return value of get_config() must be
of the type array, integer returned in file:2
Stack trace:
#0 file(4): get_config()
#1 {main}
thrown in file on line 2✔ Coercive Scalar Types
function logmsg(string $msg, int $level, float $severity) {
var_dump($msg); // string(1) "1"
var_dump($level); // int(2)
var_dump($severity); // float(3)
}
logmsg(1, "2.5 bananas", 3);Notice: A non well formed numeric value encountered in file on line 2✔ Strict Scalar Types
declare(strict_types=1);
...
logmsg(1, "2.5", 3);Fatal error: Uncaught TypeError: Argument 1 passed to logmsg() must be of the
type string, integer given, called in file on line 7 and defined in file:3
Stack trace:
#0 file(7): logmsg(1, '2.5', 3)
#1 {main}
thrown in file on line 2✔ Anonymous Classes
return new class($controller) implements Page {
public function __construct($controller) {
/* ... */
}
/* ... */
};
class MyObject extends MyStuff {
public function getInterface() {
return new class implements MyInterface {
/* ... */
};
}
}✔ Coalesce Operator
$a = NULL;
$b = 0;
$c = 2;
echo $a ?? $b; // 0
echo $c ?? $b; // 2
echo $a ?? $b ?? $c; // 0
echo $a ?? $x ?? $c; // 2✔ Spaceship Operator
function cmp_php5($a, $b) {
return ($a < $b) ? -1 : (($a >$b) ? 1 : 0);
}
function cmp_php7($a, $b) {
return $a <=> $b;
}✔ Removal of many deprecated features
(Your PHP4 code will break!)
- ext/ereg (use ext/pcre instead)
- preg_replace() eval modifier (use preg_replace_callback() instead)
- ext/mysql (use ext/mysqli or ext/pdo_mysql instead)
- Assignment of new by reference
- Scoped calls of non-static methods from incompatible $this context
- dl() in php-fpm
- set_magic_quotes_runtime() and magic_quotes_runtime()
- set_socket_blocking() (use stream_set_blocking() instead)
- mcrypt_generic_end() (use mcrypt_generic_deinit() instead)
- mcrypt_ecb, mcrypt_cbc, mcrypt_cfb and mcrypt_ofb
(use mcrypt_encrypt() and mcrypt_decrypt() instead)
- datefmt_set_timezone_id() and IntlDateFormatter::setTimeZoneID()
(use datefmt_set_timezone() or IntlDateFormatter::setTimeZone() instead)
- xsl.security_prefs (use XsltProcessor::setSecurityPrefs() instead)
- iconv.input_encoding, iconv.output_encoding, iconv.internal_encoding,
mbstring.http_input, mbstring.http_output and mbstring.internal_encoding
(use php.input_encoding, php.internal_encoding and php.output_encoding instead)
- $is_dst parameter of the mktime() and gmmktime() functions
- # style comments in ini files (use ; style comments instead)
- String category names in setlocale() (use LC_* constants instead)
- Unsafe curl file uploads (use CurlFile instead)
- PDO::PGSQL_ATTR_DISABLE_NATIVE_PREPARED_STATEMENT driver option
(use PDO::ATTR_EMULATE_PREPARES instead)
- CN_match and SNI_server_name stream context option (use peer_name instead)✔ New reserved words:
- bool
- int
- float
- string
- null
- false
- true
- resource
- object
- mixed
- numeric
✔ 64-bit integer support on Windows
✔ Cleanup edge-case integer overflow/underflow
✔ Support for strings with length >= 2^31 bytes in 64 bit builds.
✔ Parse error on invalid numeric literals
$mask = 0855; // Parse error: Invalid numeric literal✔ Uniform variable syntax
// left-to-right
$this->$belongs_to['column']
// vs.
$this->{$belongs_to['column']}
// support missing combinations of operations
$foo()['bar']()
[$obj1, $obj2][0]->prop
getStr(){0}
// support nested ::
$foo['bar']::$baz
$foo::$bar::$baz
$foo->bar()::baz()
// support nested ()
foo()()
$foo->bar()()
Foo::bar()()
$foo()()
// support operations on arbitrary (...) expressions
(...)['foo']
(...)->foo
(...)->foo()
(...)::$foo
(...)::foo()
(...)()
// two more practical examples for the last point
(function() { ... })()
($obj->closure)()
// support all operations on dereferencable scalars
// (not very useful)
"string"->toLower()
[$obj, 'method']()
'Foo'::$bar✔ Unicode Codepoint Escape Syntax
echo "\u{202E}Right-to-left text";
echo " \u{26BD}";Right-to-left text ⚽
✔ ICU IntlChar class added to intl extension
✔ CSPRNG
$int = random_int(-500, 500);
$bytes = random_bytes(10);
var_dump( $int );
var_dump( bin2hex($bytes) );int(-433) string(20) "dafd192c3a58142e2586"
Top-5 Things that might bite you
For the full list see
Left-to-right semantics for complicated expressions
$$foo['bar']['baz'] // interpreted as ($$foo)['bar']['baz']
$foo->$bar['baz'] // interpreted as ($foo->$bar)['baz']
$foo->$bar['baz']() // interpreted as ($foo->$bar)['baz']()
Foo::$bar['baz']() // interpreted as (Foo::$bar)['baz']()To restore the previous behaviour add explicit curly braces:
${$foo['bar']['baz']}
$foo->{$bar['baz']}
$foo->{$bar['baz']}()
Foo::{$bar['baz']}()Detection: phan or unit test failures
Removed support for /e (PREG_REPLACE_EVAL) modifier
echo preg_replace('/:-:(.*?):-:/e', '$this->pres->\\1', $text);Change to:
echo preg_replace_callback(
'/:-:(.*?):-:/',
function($matches) {
return $this->pres->{$matches[1]}; // Careful!
},
$text);Detection: grep, warnings in logs or unit test failures
$HTTP_RAW_POST_DATA global removed
if (empty($GLOBALS['HTTP_RAW_POST_DATA']) &&
strpos($_SERVER['CONTENT_TYPE'], 'www-form-urlencoded') === false) {
$GLOBALS['HTTP_RAW_POST_DATA'] = file_get_contents("php://input");
}Detection: grep, warnings in logs or unit test failures
session.lazy_write enabled by default
session.lazy_write = 0Detection: Can cause out-of-band session read timing issues
Invalid octal literals now produce a parse error
echo 05678; // PHP 5.x outputs 375Parse error: Invalid numeric literal in file.php on line 2
Detecting parse errors is easy: php -l
Static Analysis
% phan -h
Usage: ./phan [options] [files...]
-f, --file-list <filename>
A file containing a list of PHP files to be analyzed
-r, --file-list-only
A file containing a list of PHP files to be analyzed to the
exclusion of any other directories or files passed in. This
is useful when running Phan from a stored state file and
passing in a small subset of files to be re-analyzed.
-l, --directory <directory>
A directory to recursively read PHP files from to analyze
-3, --exclude-directory-list <dir_list>
A comma-separated list of directories for which any files
included from that directory will not be analysis. Note
that adding a directory here will not cause its files to
be parsed.
-d, --project-root-directory
Hunt for a directory named .phan in the current or parent
directory and read configuration file config.php from that
path.
-m <mode>, --output-mode
Output mode from 'text', 'json', 'codeclimate', or 'checkstyle'
-o, --output <filename>
Output filename
-p, --progress-bar
Show progress bar
-a, --dump-ast
Emit an AST for each file rather than analyze
-e, --expand-file-list
Expand the list of files passed in to include any files
that depend on elements defined in those files. This is
useful when running Phan from a state file and passing in
just the set of changed files.
-q, --quick
Quick mode - doesn't recurse into all function calls
-b, --backward-compatibility-checks
Check for potential PHP 5 -> PHP 7 BC issues
-i, --ignore-undeclared
Ignore undeclared functions and classes
-y, --minimum-severity <level in {0,5,10}>
Minimum severity level (low=0, normal=5, critical=10) to report.
Defaults to 0.
-c, --parent-constructor-required
Comma-separated list of classes that require
parent::__construct() to be called
-x, --dead-code-detection
Emit issues for classes, methods, functions, constants and
properties that are probably never referenced and can
possibly be removed.
-j, --processes <int>
The number of parallel processes to run during the analysis
phase. Defaults to 1.
-z, --signature-compatibility
Analyze signatures for methods that are overrides to ensure
compatiiblity with what they're overriding.
-h,--help
This help information% phan -i -b display.php
display.php:416 CompatError expression may not be PHP 7 compatibleecho preg_replace('/:-:(.*?):-:/e', '$this->pres->\\1', $text);echo preg_replace_callback(
'/:-:(.*?):-:/',
function($matches) {
return $this->pres->$matches[1]; // Oops!
},
$text);echo preg_replace_callback(
'/:-:(.*?):-:/',
function($matches) {
return $this->pres->{$matches[1]}; // Ok
},
$text);% git clone https://github.com/Seldaek/monolog.git
% cd monolog
% find . -name '*.php' | grep -v test > filelist.txt
% phan -i -f filelist.txt
./src/Monolog/Handler/ChromePHPHandler.php:178 PhanTypeMismatchReturn Returning type int but headersAccepted() is declared to return bool
./src/Monolog/Handler/ElasticSearchHandler.php:124 PhanTypeMismatchArgumentInternal Argument 3 (previous) is \elastica\exception\exceptioninterface but \runtimeexception::__construct() takes \runtimeexception|\throwable
./src/Monolog/Handler/FirePHPHandler.php:81 PhanTypeMismatchReturn Returning type array but createRecordHeader() is declared to return string
./src/Monolog/Handler/FirePHPHandler.php:153 PhanTypeMismatchArgumentInternal Argument 1 (array_arg) is string but \current() takes array
./src/Monolog/Handler/FirePHPHandler.php:154 PhanTypeMismatchArgumentInternal Argument 1 (array_arg) is string but \current() takes array
./src/Monolog/Handler/FirePHPHandler.php:154 PhanTypeMismatchArgumentInternal Argument 1 (array_arg) is string but \key() takes array
./src/Monolog/Handler/FlowdockHandler.php:70 PhanTypeMissingReturn Method \monolog\handler\flowdockhandler::getdefaultformatter is declared to return \monolog\formatter\formatterinterface but has no return value
./src/Monolog/Handler/GelfHandler.php:55 PhanTypeMismatchProperty Assigning null to property but \monolog\handler\gelfhandler::publisher is \gelf\imessagepublisher|\gelf\publisher|\gelf\publisherinterface
./src/Monolog/Handler/MandrillHandler.php:49 PhanSignatureMismatch Declaration of function send($content, array $records) should be compatible with function send(string $content, array $records) defined in ./src/Monolog/Handler/MailHandler.php:46
./src/Monolog/Handler/NativeMailerHandler.php:117 PhanSignatureMismatch Declaration of function send($content, array $records) should be compatible with function send(string $content, array $records) defined in ./src/Monolog/Handler/MailHandler.php:46
./src/Monolog/Handler/RedisHandler.php:41 PhanTypeMismatchDefault Default value for int $capSize can't be bool
./src/Monolog/Handler/SocketHandler.php:115 PhanTypeMismatchProperty Assigning float to property but \monolog\handler\sockethandler::timeout is int
./src/Monolog/Handler/SocketHandler.php:126 PhanTypeMismatchProperty Assigning float to property but \monolog\handler\sockethandler::writingTimeout is int
./src/Monolog/Handler/SocketHandler.php:218 PhanTypeMismatchArgumentInternal Argument 2 (seconds) is float but \stream_set_timeout() takes int
./src/Monolog/Handler/SocketHandler.php:218 PhanTypeMismatchArgumentInternal Argument 3 (microseconds) is float but \stream_set_timeout() takes int
./src/Monolog/Handler/SocketHandler.php:274 PhanTypeMismatchProperty Assigning resource to property but \monolog\handler\sockethandler::resource is null
./src/Monolog/Handler/StreamHandler.php:65 PhanTypeMismatchProperty Assigning null to property but \monolog\handler\streamhandler::stream is resource|string
./src/Monolog/Handler/StreamHandler.php:86 PhanTypeMismatchProperty Assigning null to property but \monolog\handler\streamhandler::stream is resource|string
./src/Monolog/Handler/StreamHandler.php:105 PhanTypeMismatchProperty Assigning array|string to property but \monolog\handler\streamhandler::errorMessage is null
./src/Monolog/Handler/SwiftMailerHandler.php:43 PhanSignatureMismatch Declaration of function send($content, array $records) should be compatible with function send(string $content, array $records) defined in ./src/Monolog/Handler/MailHandler.php:46
./src/Monolog/Handler/SyslogUdp/UdpSocket.php:38 PhanTypeMismatchProperty Assigning null to property but \monolog\handler\syslogudp\udpsocket::socket is resourceChromePHPHandler.php:178 PhanTypeMismatchReturn Returning type int but headersAccepted() is declared to return bool/**
* Verifies if the headers are accepted by the current user agent
*
* @return Boolean
*/
protected function headersAccepted() {
if (empty($_SERVER['HTTP_USER_AGENT'])) {
return false;
}
return preg_match('{\bChrome/\d+[\.\d+]*\b}', $_SERVER['HTTP_USER_AGENT']);
}
FirePHPHandler.php:154 PhanTypeMismatchArgumentInternal Argument 1 (array_arg) is string but \current() takes array/**
* Base header creation function used by init headers & record headers
*
* @param array $meta Wildfire Plugin, Protocol & Structure Indexes
* @param string $message Log message
* @return array Complete header string ready for the client as key and message as value
*/
protected function createHeader(array $meta, $message) {
$header = sprintf('%s-%s', self::HEADER_PREFIX, join('-', $meta));
return array($header => $message);
}
/**
* Creates message header from record
*
* @see createHeader()
* @param array $record
* @return string
*/
protected function createRecordHeader(array $record)
{
// Wildfire is extensible to support multiple protocols & plugins in a single request,
// but we're not taking advantage of that (yet), so we're using "1" for simplicity's sake.
return $this->createHeader(
array(1, 1, 1, self::$messageIndex++),
$record['formatted']
);
}
/**
* Creates & sends header for a record, ensuring init headers have been sent prior
*
* @see sendHeader()
* @see sendInitHeaders()
* @param array $record
*/
protected function write(array $record)
{
if (!self::$sendHeaders) {
return;
}
// WildFire-specific headers must be sent prior to any messages
if (!self::$initialized) {
self::$initialized = true;
self::$sendHeaders = $this->headersAccepted();
if (!self::$sendHeaders) {
return;
}
foreach ($this->getInitHeaders() as $header => $content) {
$this->sendHeader($header, $content);
}
}
$header = $this->createRecordHeader($record);
if (trim(current($header)) !== '') {
$this->sendHeader(key($header), current($header));
}
}PHP 7 Tuning
Check your phpinfo()
Opcache
opcache.memory_consumption=2048
opcache.max_accelerated_files=100000
opcache.validate_timestamps=1
opcache.revalidate_freq=2
opcache.save_comments=0
opcache.enable_file_override=0
opcache.enable_cli=0
opcache.max_wasted_percentage=10
opcache.interned_strings_buffer=128
opcache.fast_shutdown=1
opcache.huge_code_pages=1Opcache
Huge Pages
$ sysctl -w vm.nr_hugepages=512
vm.nr_hugepages = 512
(Add it to your /etc/sysctl.conf)
$ grep Huge /proc/meminfo
AnonHugePages: 6144 kB
HugePages_Total: 512
HugePages_Free: 300
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kBUSE_ZEND_ALLOC_HUGE_PAGES=1 httpd ...increase realpath_cache_size
realpath_cache_size=128kIf using MySQL, use mysqlnd
Check your command buffer usage
DocumentRoot on tmpfs
$ mount | grep tmpfs
tmpfs on /var/www type tmpfs (rw,relatime,size=12288000k,mode=755)
$ ls -la /var/www
total 5
drwxr-xr-x 5 root root 160 Feb 23 02:47 .
drwxr-xr-x 26 root root 4096 Feb 7 19:40 ..
lrwxrwxrwx 1 root root 14 Feb 23 02:47 current -> /var/www/A
drwxrwxr-x 25 apache apache 640 Feb 11 22:04 A
drwxrwxr-x 25 apache apache 640 Feb 11 22:04 BApplication-level changes?
Remember this?
$a = [];
for($i=0; $i < 100000;$i++) {
$a[] = ['abc','def','ghi','jkl','mno','pqr'];
}
echo memory_get_usage(true);
// PHP 5.x 109M
// PHP 7.0 42M no opcache
// PHP 7.0 6M with opcache enabledUse it!
include 'config.php'; // $config = [ ... ]include 'countries.php'; // $countries = [ 'CA'=>'Canada', ... ]Hyperthreading and NUMA
- HyperThreading handles extreme loads better
- If you don't have multi-socket servers, turn on HT and move on
- For multi-socket servers, things get interesting
$ lscpu
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 48
On-line CPU(s) list: 0-47
Thread(s) per core: 2
Core(s) per socket: 12
Socket(s): 2
NUMA node(s): 2
NUMA node0 CPU(s): 0-11,24-35
NUMA node1 CPU(s): 12-23,36-47
Solutions?
- numactl --interleave=all httpd/php-fpm
- split multi-socket with containers
- BIOS Snoop Mode setting? HS/ES/COD?
- ignore it
Let's deploy it!
Atomic
No performance hit
- No restarts
- No LB removal
- No thundering herd
- Cache reuse
Must be able to serve two versions of the site concurrently!
Requests that begin on DocumentRoot A must finish on A
Set the DocumentRoot to symlink target!
Easy with nginx
fastcgi_param DOCUMENT_ROOT $realpath_rootApache
Avoid hardcoding full paths
Watch your include_path setting
incpath extension can resolve your include_path for you
Version all static assets
DB Schema changes need special care
PHP 7 in production
Thank You
Report Bugs
Useful bug reports, please!