Improving PHP Application performance with APC Presented by James McLean

Improving PHP Application Performance with APC Who is this clown? PHP Introduction APC Introduction Testing Environment Opcodes? APC Installation APC Configuration APC Shared Memory APC Vanilla Install Performance APC & Stat APC & Caching Variables Conclusion

Who is this clown?

PHP Introduction

APC Introduction

Testing Environment

Opcodes?

APC Installation

APC Configuration

APC Shared Memory

APC Vanilla Install Performance

APC & Stat

APC & Caching Variables

Conclusion

Who is this clown? PHP User since early Version 3. PHP Developer since early 2000 Zend Certified Engineer, PHP5 Web Developer at Iugo Pty Ltd, Adelaide. irc://irc.freenode.org/#phpc Channel Operator Personal Blog: http://blog.phpguy.org

PHP User since early Version 3.

PHP Developer since early 2000

Zend Certified Engineer, PHP5

Web Developer at Iugo Pty Ltd, Adelaide.

irc://irc.freenode.org/#phpc Channel Operator

Personal Blog: http://blog.phpguy.org

PHP Introduction PHP: Hypertext Preprocessor PHP/FI, Created in 1995 by Rasmus Lerdorf General Purpose Language Ideally suited to Web Development Can be used on the command line and for shell scripting, even for GUI apps!

PHP: Hypertext Preprocessor

PHP/FI, Created in 1995 by Rasmus Lerdorf

General Purpose Language

Ideally suited to Web Development

Can be used on the command line and for shell scripting, even for GUI apps!

APC Introduction APC: Alternative PHP Cache. Free, Open Source Opcode Cache. Benefit from simply installing the module, no code changes required. Ability to cache variables with code changes.

APC: Alternative PHP Cache.

Free, Open Source Opcode Cache.

Benefit from simply installing the module, no code changes required.

Ability to cache variables with code changes.

Testing Environment All tests were performed with the following: Intel Core 2 Quad Q9450 @ 3.2Ghz 8GB DDR2 800Mhz RAM APC 3.0.19, PHP 5.2.6 & PHP 5.2.6 From Gentoo Portage Custom OO PHP5 Framework PDO Used for all Database Access ab2 -k -c 50 -t 300 http://devwww.vortexdvd.com/

All tests were performed with the following:

Intel Core 2 Quad Q9450 @ 3.2Ghz

8GB DDR2 800Mhz RAM

APC 3.0.19, PHP 5.2.6 & PHP 5.2.6 From Gentoo Portage

Custom OO PHP5 Framework

PDO Used for all Database Access

ab2 -k -c 50 -t 300 http://devwww.vortexdvd.com/

Opcodes? Opcodes are, simply, compiled PHP code. Discarded after the page has been executed. PHP Page Compilation: - Scanning / Lexing. Plain Text Code turned into Tokens - Parsing. Tokens are collected into Expressions. - Compilation. Expressions are translated into Opcodes for Execution. - Execution. Opcode stacks are processed, one at a time. APC caches the Opcodes for later execution!

Opcodes are, simply, compiled PHP code.

Discarded after the page has been executed.

PHP Page Compilation:

- Scanning / Lexing. Plain Text Code turned into Tokens

- Parsing. Tokens are collected into Expressions.

- Compilation. Expressions are translated into Opcodes for Execution.

- Execution. Opcode stacks are processed, one at a time.

APC caches the Opcodes for later execution!

APC Installation Quick and Easy to install! PECL - http://pecl.php.net - # pecl install apc . GNU/Linux Package Managers. - Gentoo Portage: dev-php5/pecl-apc . - Debian/Ubuntu: # pecl install apc Windows: http://pecl4win.php.net Ensure the module is loaded into php.ini. - extension=apc.so

Quick and Easy to install!

PECL - http://pecl.php.net

- # pecl install apc .

GNU/Linux Package Managers.

- Gentoo Portage: dev-php5/pecl-apc .

- Debian/Ubuntu: # pecl install apc

Windows: http://pecl4win.php.net

Ensure the module is loaded into php.ini.

- extension=apc.so

APC Configuration In a basic APC installation, two major configuration options affect the performance of your applications apc.shm_size – Shared Memory Size. apc.stat – Stat files.

In a basic APC installation, two major configuration options affect the performance of your applications

apc.shm_size – Shared Memory Size.

apc.stat – Stat files.

APC Shared Memory apc.shm_size controls how much memory will be set aside for APC to use. Memory is cheap! Increasing the memory available to APC will not always improve performance signifigantly.

apc.shm_size controls how much memory will be set aside for APC to use.

Memory is cheap!

Increasing the memory available to APC will not always improve performance signifigantly.

APC Vanilla Install Performance As mentioned before, you can get a performance gain, simply from installing the module. No APC Enabled: APC Enabled, Vanilla Settings: Requests per second: 71.27 [#/sec] (mean) Time per request: 701.510 [ms] (mean) Time per request: 14.030 [ms] (mean, across all concurrent requests) Transfer rate: 898.79 [Kbytes/sec] received Requests per second: 93.55 [#/sec] (mean) Time per request: 534.454 [ms] (mean) Time per request: 10.689 [ms] (mean, across all concurrent requests) Transfer rate: 1181.05 [Kbytes/sec] received Whoa!

As mentioned before, you can get a performance gain, simply from installing the module.

No APC Enabled:

APC Enabled, Vanilla Settings:

APC & Stat No.. Not that stat...

No.. Not that stat...

APC & Stat By Default, PHP checks the modification time of the script and all includes at Execution. You can disable stat checking, for extra performance! Web Server restarts required when files change.

By Default, PHP checks the modification time of the script and all includes at Execution.

You can disable stat checking, for extra performance!

Web Server restarts required when files change.

APC & Stat Stat Testing: $ ab2 -k -c 50 -t 300 http://devwww.vortexdvd.com/ apc.stat = on apc.stat = off Requests per second: 129.46 [#/sec] (mean) Time per request: 386.208 [ms] (mean) Time per request: 7.724 [ms] (mean, across all concurrent requests) Transfer rate: 1634.77 [Kbytes/sec] received Requests per second: 278.58 [#/sec] (mean) Time per request: 179.481 [ms] (mean) Time per request: 3.590 [ms] (mean, across all concurrent requests) Transfer rate: 3516.54 [Kbytes/sec] received EPIC WIN!!

Stat Testing:

$ ab2 -k -c 50 -t 300 http://devwww.vortexdvd.com/

apc.stat = on

apc.stat = off

APC & Stat Turning off File Stat yields an excellent performance benefit! Best if your site files don't change very often. Requires a web-server restart when the files are changed.

Turning off File Stat yields an excellent performance benefit!

Best if your site files don't change very often.

Requires a web-server restart when the files are changed.

APC & Variable Caching APC allows you to cache variables for speed. Large variables and variables that dont change often, ideally suited to variable caching. Caching Database Query Result Sets can result in extra performance, and save your database!

APC allows you to cache variables for speed.

Large variables and variables that dont change often, ideally suited to variable caching.

Caching Database Query Result Sets can result in extra performance, and save your database!

APC & Variable Caching Custom code to enable or disable use of the Query Cache. Query Cache Disabled Query Cache Enabled Requests per second: 124.55 [#/sec] (mean) Time per request: 401.436 [ms] (mean) Time per request: 8.029 [ms] (mean, across all concurrent requests) Transfer rate: 1572.57 [Kbytes/sec] received Requests per second: 91.97 [#/sec] (mean) Time per request: 543.680 [ms] (mean) Time per request: 10.874 [ms] (mean, across all concurrent requests) Transfer rate: 1160.01 [Kbytes/sec] received WIN!

Custom code to enable or disable use of the Query Cache.

Query Cache Disabled

Query Cache Enabled

Conclusion APC is a great way to get some 'free speed' out of your applications. - Benefit from installing the module, vanilla config! - Minor config changes for a huge benefit with Stat APC doesn't suit everyone and all situations. - Does not suit distributed servers or load balanced. Overall, APC is worth a look next time you need to improve your PHP application performance.

APC is a great way to get some 'free speed' out of your applications.

- Benefit from installing the module, vanilla config!

- Minor config changes for a huge benefit with Stat

APC doesn't suit everyone and all situations.

- Does not suit distributed servers or load balanced.

Overall, APC is worth a look next time you need to improve your PHP application performance.

References http://www.php.net/apc http://www.debian-administration.org/articles/574 http://blog.phpguy.org/2007/09/20/apc-and-web-application-performance/ http://blog.phpguy.org/2007/09/21/apc-and-web-application-performance-take-2/ http://blog.libssh2.org/index.php?/archives/92-Understanding-Opcodes.html

http://www.php.net/apc

http://www.debian-administration.org/articles/574

http://blog.phpguy.org/2007/09/20/apc-and-web-application-performance/

http://blog.phpguy.org/2007/09/21/apc-and-web-application-performance-take-2/

http://blog.libssh2.org/index.php?/archives/92-Understanding-Opcodes.html