This document summarizes insights from redesigning the mobilesport.ch website. The main goals were to improve response times and make exercises easier to handle. Statistics on the site's content are provided. Testing showed that moving from Apache to Nginx improved performance. Caching, AJAX, and Memcached were implemented to enhance speed. Problems were experienced with the WPML plugin, including bugs and slow support. Lessons learned include issues with plugins and caching, and how refactoring requires thorough analysis.

1. WordPress Zurich Meetup
Mobilesport.ch - Insights
02. Juni 2014

2. Table of contents
mobilesport.ch - Insights
 What is the idea of mobilesport.ch
 Main goals of the relaunch
 A few statistics
 Does „strong“ hardware make your WordPress faster?
 Nginx vs. Apache
 Site caching, AJAX and memcached
 Used plugins
 The WPML struggle is real
 Learnings

3. What is the idea of mobilesport.ch
mobilesport.ch - Insights
 Platform for sports trainers and teachers
 …And other people who are keen on sports
 Search and find exercises covering their needs
 Put exercises together on lists
 Re-use and share exercise lists with others
 And of course: Use the contents in their lessons or make
their own lessons to keep themselves fit

4. What is the idea of mobilesport.ch
mobilesport.ch - Insights

5. What is the idea of mobilesport.ch
mobilesport.ch - Insights

6. What is the idea of mobilesport.ch
mobilesport.ch - Insights

7. Main goals
mobilesport.ch - Insights
 1. Faster response times
 2. Easier to handle and filter sports exerices
 3. Refactor / modernize code base (our goal)

8. A few statistics
mobilesport.ch - Insights
 11‘950 posts
 4‘222 in german, 4‘171 in french, 3‘557 in italian
 191‘457 post meta data records
 1‘440 terms
 223‘578 term relationships
 1‘258 registered users
 2‘387 favorite lists
 33‘377 list items
 And this, combined with the WPML plugin is
essentially what made it slow.

9. Does „strong“ hardware make your WordPress faster?
mobilesport.ch - Insights

10. Does „strong“ hardware make your WordPress faster?
mobilesport.ch - Insights
 More CPU or RAM != Faster Request
 More CPU/RAM == More Request/sec
 More RAM == More possibilities to cache
How to make a single request faster?
 Fast basic installation (i.e. nginx/php5-fpm/hhvm)
 Write efficient code
 Cache as much as possible

11. nginx vs. apache2 - Installation
mobilesport.ch - Insights
Live Machine Test Machine
Installation Type Physical Server VPS / Amazon EC2
CPU 2x6 2.5 GHz Cores (Xeon) 1 vCPU (Xeon E5-2670)
RAM 8x8 GB (64GB total) 3.75 GB
Harddisks Native SSD EBS Network Storage
Webserver Apache 2.2.22 Nginx 1.4.1
PHP Installation mod_php5 / apache2handler php5-fpm
PHP Version PHP 5.4.x PHP 5.5.x
MySQL Version 5.5.37 5.5.37
Memcached 1.4.14 1.4.14

12. nginx vs. apache2 - Results
mobilesport.ch - Insights
Live Machine Test Machine
Uncached Request (HT Disabled) 1.1s – 1.3s Not tested
Uncached Request (HT Enabled) 700 – 800ms 400 – 500ms
WordPress Ajax Request 200 – 350ms 100 – 200ms
Cached Request (HTML Cache) 30 – 60ms 20 – 50ms
Cached Requests/sec - simple siege ~2500 Req/s ~180 Req/s
Cached Requests/sec – CPU Usage 10-15% 20-30%
Uncached Requests/sec - simple siege ~50 Req/s ~20 Req/s
Uncached Requests/sec – CPU Usage 30-35% +100%

13. Site caching, AJAX, memcached
mobilesport.ch - Insights
What makes the new mobilesport.ch faster?
 Site caching (Serving cached sites from wp-config.php)
 Using AJAX for dynamic content
 Don‘t load certain modules while DOING_AJAX
 Cache complex business logic (wp_cache_*)
 Cache complex DB queries
 Use memcached as WP_Object_Cache

14. Plugins
mobilesport.ch - Insights
Which plugins did we use?
 Antispam Bee
 Contact Form 7
 Google XML Sitemaps
 Installer (Especially for WPML)
 JWPlayer 6 Plugin
 TinyMCE Advanced
 WPML
 wpSEO

15. The WPML struggle is real
mobilesport.ch - Insights
Maybe you have seen tweets like these:

16. The WPML struggle is real
mobilesport.ch - Insights
What were the problems
 Various bugs with memcached
 Looks like WPML is not actually tested for persistent caching
 Proper cache invalidation missing
 Very slow support
 Support answers quite fast, but…
 Solutions are developed slowly (or not at all)
 New (major) bugs with every update
 We are live, but there are still unfixed bugs
 Memcached is „completely disabled“ in backend
 Features like bulk editing removed

17. The WPML struggle is real
mobilesport.ch - Insights
What were the problems
 Various bugs with memcached
 Looks like WPML is not actually tested for persistent caching
 Proper cache invalidation missing
 Very slow support
 Support answers quite fast, but…
 Solutions are developed slowly (or not at all)
 New (major) bugs with every update
 We are live, but there are still unfixed bugs
 Memcached is „completely disabled“ in backend
 Features like bulk editing removed

18. Learnings
mobilesport.ch - Insights
 We‘re not going to use WPML anymore
 Hint: We migrated every project to our own ML solution
 Mobilesport.ch is our last project where we use WPML
 When using memcached
 …Make sure you have enough RAM allocated
 …Make sure that all plugins work properly
 If possible, use nginx/php5-fpm configurations
 You might want to try hhvm instead of php5-fpm
 Refactoring a whole code base needs a lot of analysis
 Updating WordPress or a plugin can cause serious issues

19. Michael Sebel
Software-Engineer
Twitter: @msebel
michael.sebel@blogwerk.com
Questions and contact
mobilesport.ch - Insights