APM (Alternative PHP Monitor)

APM (Alternative PHP Monitor) is a monitoring extension enabling native Application Performance Management (APM) for PHP. It doesn't require any modification to your application's code and let's you collect performance metrics as well as catching issues that may arise.

Installing

From PECL:

1. $ sudo pecl install apm

From source:

1. $ git clone https://github.com/patrickallaert/php-apm.git

2. $ cd php-apm

3. $ phpize

4. Configure the extension, by default, sqlite3, MariaDB/MySQL, StatsD and Socket support are enabled:

   $ ./configure [--with-sqlite3[=DIR]] [--with-mysql[=DIR]] [--enable-statsd] [--enable-socket] [--with-debugfile[=FILE]]
   

   To disable the support of a --with-* switch, use: --without-*, example: $ ./configure --without-sqlite3 To disable the support of a --enable-* switch, use: --disable-*, example: $ ./configure --disable-socket

5. Compile it:

   $ make [-j]
   

   Tip: use -j to activate parallel compilation.

6. Install it:

   $ sudo make install
   

Upgrading

From 2.0 to 2.1

MariaDB / MySQL

ALTER TABLE request ADD COLUMN method TEXT NOT NULL;

SQLite

ALTER TABLE request ADD COLUMN method TEXT NOT NULL DEFAULT '';

Configuration

Common

1. Activate the extension in the php configuration by adding:

   extension=apm.so

   Note: APM depends on JSON, so the apm.so extension must be loaded after JSON!

MariaDB/MySQL driver

The MariaDB/MySQL driver lets you store errors and stats in a local, remote or shared database.

1. Create a user/database for storing APM events.

2. Set the following settings in the php configuration:

   apm.mysql_enabled=1
   ; Error reporting level specific to the MariaDB/MySQL driver, same level as for PHP's *error_reporting*
   apm.mysql_error_reporting=E_ALL|E_STRICT
   apm.mysql_host=<host>
   ;apm.mysql_port=<port>
   apm.mysql_user=<user>
   apm.mysql_pass=<password>
   apm.mysql_db=<dbname>

SQLite driver

The SQLite driver lets you store errors and stats in a local SQLite database.

Note that if performance matters, you should better use the MariaDB/MySQL driver.

1. Create the directory for the SQLite database as it will be referenced in the setting: apm.sqlite_db_path (see next step):

   $ mkdir -p /var/php/apm/db/
   $ chmod a+rwx /var/php/apm/db/
   

2. Set the following settings in the php configuration:

   apm.sqlite_enabled=1
   ; The directory containing the "events" file
   apm.sqlite_db_path="/path/to/directory/configured/in/previous/step."
   ; Error reporting level specific to the SQLite3 driver, same level as for PHP's *error_reporting*
   apm.sqlite_error_reporting=E_ALL|E_STRICT

StatsD driver

The StatsD driver is handy to send performance metrics of your web sites/applications directly to StatsD, without interfering with your code. The most common backend for StatsD is Graphite, see [Etsy's blog post on StatsD/Graphite], but other backends exist as well.

1. Install StatsD.

2. Configure it in the php configuration:

   ; Whether to enable the statsd driver
   apm.statsd_enabled=On
   ; Host of the statsd server
   apm.statsd_host=localhost
   ; Port of the statsd server
   apm.statsd_port=3306

Socket driver

The socket driver lets you send errors and stats directly by Unix and/or TCP sockets. This is handy if you want to write you own piece of code to handle those.

1. Configure it in the php configuration:

   ; Whether to enable the socket driver
   apm.socket_enabled=On
   ; Socket path (accept multiple entries, separated by "|", prefixed with "file:" or "tcp:")
   ; Example: apm.socket_path=file:/var/tmp/apm.sock|tcp:localhost:1234
   apm.socket_path=file:/tmp/apm.sock

Web frontend

The web frontend to visualize the data is now available at: https://github.com/patrickallaert/php-apm-web

Advanced configuration

; Application identifier, helps identifying which application is being monitored
apm.application_id="My application"
; Enable the capture of events such as errors, notices, warnings,...
apm.event_enabled=On|Off
; Maximum duration in ms a request can take before it gets recorded
apm.stats_duration_threshold="100"
; Maximum User CPU time in ms a request can take before it gets recorded
apm.stats_user_cpu_threshold="100"
; Maximum System CPU time in ms a request can take before it gets recorded
apm.stats_sys_cpu_threshold="10"
; Boolean controlling whether the stacktrace should be stored or not
apm.store_stacktrace=On|Off
; Boolean controlling whether the ip should be stored or not
apm.store_ip=On|Off
; Boolean controlling whether the cookies should be stored or not
apm.store_cookies=On|Off
; Boolean controlling whether the POST variables should be stored or not
apm.store_post=On|Off
; Maximum recursion depth used when dumping a variable
; NOTE: With today's application complexity, the amount of data collected in stacktraces
; including arguments can lead to several thousands of MiB of memory consumed.
; We recommend increasing this value with care.
apm.dump_max_depth=1

; For the configuration below, <driver_name> can be any of: sqlite, mysql, statsd or socket

; Activate or deactivate a specific driver (note also that it must be compiled in to be activated).
apm.<driver_name>_enabled=On|Off
; Whether to collect stats for this driver (ATTENTION: Has a small performance overhead when used with a DB drivers!)
apm.<driver_name>_stats_enabled=On|Off
; Error reporting level specific to this driver
apm.<driver_name>_error_reporting=E_ALL|E_STRICT
; Control which exceptions to collect (0: none exceptions collected, 1: collect uncaught exceptions (default), 2: collect ALL exceptions)
apm.<driver_name>_exception_mode=1
; Stores silenced events (Errors, warnings, notices,... that are muted with the PHP '@' operator)
apm.<driver_name>_process_silenced_events=On|Off

For a list of all PHP ini directives, take a look at the apm.ini file.

Common issues

• SQLite database isn't created: this usually happens when your webserver or PHP process (fcgi, fpm) has no filesystem access:

  • Check your configuration: maybe SQLite isn't configured properly for APM
  • Check permissions on the directory and events file for the user that PHP runs as (sometimes it's your webserver user)
  • Check open_basedir restrictions

• Not all data on the specific PHP scripts in which errors occur is collected:

  • Usually an access issue, check permissions
  • Sometimes this is due to open_basedir restrictions

• APM is configured correctly, but nothing shows up, and phpinfo() doesn't show anyting related to APM:

  • APM wasn't actually loaded, check if the ini file you configured is actually used by PHP
  • the APM module was tried, but fatal errors prevented it from loading; check the PHP error log, usually a dependency like JSON wasn't loaded yet