PHP Profiling/performance

PHP profiling/perfomance

Processing time,Transmission time

CPU Bandwith MemoryI/O

PHP profiling/perfomance

• Expected traffic• Traffic growth• Scalability means• Evolutions to come…

Set the context

• Contextually : search engine, file generation, task…

Establish the objectives

PHP profiling/perfomance

•Language•Framework•Libraries•…

Adapt technologies

PHP profiling/perfomance

• Smart, structured code• Lazy loading• Static variables (singletons/registries)• Cache

Code

• Autoloader• Reduce and order include_path• Client cache (HTTP headers Cache-Control, Expire)• Avoid regexps• …

Good practices

• Php.ini : realpath_cache_size• Nginx : worker_processes, open_file_cache, multi_accept, keepalive, gzip• Cache op-code• Disable logs

Server configuration

PHP profiling/perfomance

• Ponctual inefficiencies/bottlenecks detection

• Monitoring (analytics, alert tools)• Take comparison points (before/after)• Know when to stop• Never rely on intuition!

Measure

PHP profiling/perfomance

Load tests• ApacheBenchmark• Siege• Httperf• …

Profiling• Xdebug• XHProf• …

Measuring tools

PHP profiling/perfomance

ApacheBenchmarkab -n 50 -c 2 -v 1 -p 'post.txt' -T 'application/json'-H 'Authorization: Bearer eyJ0eXAi.eyJpc3nYXJ.KznbYbc' 'http://api.gma.my/account/authenticate?alt=json&metadata[foo]=Hello&metadata[bar]=World&metadata[random Val]=Ted'> bench.txt

{ "application_key":"afaf770", "email":"ndegardin@tribalnova.com", "key":"ndegardin« }

post.txt

PHP profiling/perfomance

…Concurrency Level: 2Time taken for tests: 25.704 secondsComplete requests: 50Failed requests: 44 (Connect: 0, Receive: 0, Length: 44, Exceptions: 0)Write errors: 0Non-2xx responses: 50Total transferred: 2231974 bytesTotal POSTed: 28100HTML transferred: 2220474 bytesRequests per second: 1.95 [#/sec] (mean)Time per request: 1028.176 [ms] (mean)Time per request: 514.088 [ms] (mean, across all concurrent requests)Transfer rate: 84.80 [Kbytes/sec] received 1.07 kb/s sent 85.86 kb/s total

Connection Times (ms) min mean[+/-sd] median maxConnect: 0 0 0.1 0 0Processing: 704 1014 154.5 990 1693Waiting: 704 1014 154.5 990 1693Total: 705 1015 154.5 990 1693…

bench.txt

PHP profiling/perfomance

• PHP profiling extension• Developed by Facebook• The basic version stores traces • I diddn’t succeed in using the bundled

PHP/HTML app…• With XHPROF, the profiling is triggered by

calling xhprof_enable(), xhprof_disable()• Cool solution : auto_append_file,

auto_prepend_file in php.ini

XHProf

PHP profiling/perfomance

• Website http://xhprof.io• Sources https://github.com/gajus/xhprof.io• Profiling stored in database• php.ini

• auto_append_file=/var/www/xhprofio/inc/append.php• auto_prepend_file=/var/www/xhprofio/inc/prepend.php

• Not my recommandation

XHProf.io

PHP profiling/perfomance

• Sources https://github.com/sepehr/xhprof• Profiling stored in database (one table « details »)• Very good profiler• php.ini• auto_prepend_file=/var/www/xhprof/external/header.php• auto_append_file=/var/www/xhprof/external/footer.php

• In CGI :• activation by cookie _profile=1 • or by adding the parameter _profile=1 to the URL (adds the cookie,

then redirects)• In CLI :• auto_prepend/auto_append in/etc/php5/cli/php.ini• activation by « export XHPROF_PROFILE=1 »

XHGUI

PHP profiling/perfomance

• Activate profiling by vhost in Apache

• Activate profiling by using a nginx/PHP-FPM pool :/etc/php5/fpm/pool.d/www.conf :

• Activate profiling by vhost in nginx/PHP-FPM, in a location section

XHProf notes

fastcgi_param PHP_ADMIN_VALUE "auto_prepend_file=/var/www/xhprof/external/header.php\nauto_append_file=/var/ www/xhprof/external/footer.php";

php_admin_value auto_prepend_file "/var/www/xhprof/external/header.php"php_admin_value auto_append_file "/var/www/xhprof/external/footer.php"

php_admin_value[auto_prepend_file] = /var/www/xhprofio/inc/prepend.php"php_admin_value[auto_appendfile] = /var/www/xhprofio/inc/append.php"

PHP profiling/perfomance

• Web site http://xdebug.org/• Developed by Derik Rethans• PHP extension, now generally bundled with PHP• Features :

• Debugging functions (time, calls, scream) • Maximum nesting protection• Enhanced stacktraces• Remote debugging• Profiling• Code coverage

Xdebug

PHP profiling/perfomance

Xdebug notes about debugging

zend_extension=/usr/lib/php5/20090626/xdebug.so

xdebug.remote_enable = 1xdebug.remote_handler = "dbgp"xdebug.remote_port = 9000xdebug.remote_mode = reqxdebug.remote_host = 192.168.56.1

xdebug.profiler_enable = 1xdebug.profiler_output_dir = /var/log/xdebugxdebug.profiler_output_name = cachegrind.out.%H_%s_%R.xt

php.ini

PHP profiling/perfomance

• Prevent nginx from sending a gateway timeout (504) :in /etc/nginx/nginx.conf, add

• Remote debug events triggered externally by setting a XDEBUG_SESSION cookie and, if needed, mapping paths (client/server) in your IDE

• Remote debug CLI scripts by running export XDEBUG_CONFIG="idekey=netbeans-xdebug"and setting php.ini xdebug.remote_host

Xdebug notes about debugging

fastcgi_read_timeout 3000; keepalive_timeout 3000; keepalive_requests 3000; client_header_timeout 3000; client_body_timeout 3000;

nginx.conf

PHP profiling/perfomance

• The traces are stored as files• It often weights about 2Mo (be careful when forgetting it)• Using a fixed name (without timestamp) in php.ini

xdebug.profiler.output_name allows a run script to erase the previous one

• No official Xdebug trace extension, I suggest cachegrind.out.[…].xt

• Profilers :• WinCacheGrind (Windows) : somewhat simple• WebGrind (Web) : « For quick’n’dirty optimizations it does the

job »• KCacheGrind (KDE) : the best one• PHPStorm : not really useful

Xdebug notes about profiling

PHP profiling/perfomance

• To run it under Windows, use KDE4Win (package system similar to Cygwin’s one), it should be in the « kdesdk » package. Not available on all mirrors.

• Install GraphViz to enable drawing some charts (and add its /bin directory the the PATH)

• Check the Call Graph view!

kCacheGrind

PHP profiling/perfomance

• About different times :• The wall time includes I/O (network latency, database

accesses, waiting for an user input…)• The including time includes the children call• The CPU exclusion time (self time in KCacheGrind) is the

more relevant value• Switch between display formats :

• Percentage is better for comparing values• Time is better for assessing values

• Tweaking script parameters (input configuration, number of entries processed in database, number of iterations…) may allow to observe different phenomena

Notes about profiling

Nicolas Degardinndegardin@tribalnova.com

Merci !