Install Xdebug

Still now I’ve found Xdebug as the most useful tool to profile the bottleneck of an API. To understand the profiling result step by step- there is Webgrind.

To install Xdebug-

$ sudo apt-get install php5-xdebug

On successful installation, it should list up
$ ls /usr/lib/php5/20121212/xdebug.so

/usr/lib/php5/20121212/xdebug.so

Add Xdebug config
$ sudo vim /etc/php5/mods-available/xdebug.ini

;;;;;;;;;;;;;;;;;;;
; Xdebug config   ;
;;;;;;;;;;;;;;;;;;;
zend_extension="/usr/lib/php5/20121212/xdebug.so"
xdebug.remote_enable=1
xdebug.remote_connect_back=1
xdebug.profiler_enable=0
xdebug.profiler_enable_trigger=1
xdebug.profiler_output_dir=/tmp/
xdebug.remote_handler=dbgp
xdebug.remote_mode=req
xdebug.remote_host=127.0.0.1
xdebug.remote_port=9000

Restart fpm
$ sudo service php5-fpm restart

That’s all to setup xdebug. Just to confirm the setup, check config
$ php -i | grep "xdebug"

/etc/php5/cli/conf.d/20-xdebug.ini,
xdebug
xdebug support => enabled

and all other config details should show up there

Now send request using ?XDEBUG_PROFILE=1 e.g. http://domain/api?XDEBUG_PROFILE=1

The output should be available here
$ ls -lth /tmp/*.out.*

-rw-r--r-- 1 www-data www-data  55M Nov  9 09:16 /tmp/cachegrind.out.26030

Now watch every steps using webgrind.