Comments on: Increasing the Performance of WURFL (for at least one case) http://www.thisismobility.com/blog/2006/06/10/increasing-the-performance-of-wurfl-for-at-least-one-case/ Ripping mobility from the clutches of telecom Fri, 21 Nov 2008 13:36:27 +0000 http://wordpress.org/?v=2.6.3 By: miker http://www.thisismobility.com/blog/2006/06/10/increasing-the-performance-of-wurfl-for-at-least-one-case/#comment-9507 miker Thu, 22 Jun 2006 16:18:10 +0000 http://www.thisismobility.com/blog/?p=131#comment-9507 Hey Andrea, Actually, I had read the stuff about caching at wurfl.sourceforge.net, but I found a lot of them weren't true for the environment I was working in. I think it's because I'm working with a much bigger active device list than most sites do. The churn in the agent2id cache was actually generating a lot more load than it was saving. I made a few other changes I think might be interesting for folks running sites with frequent turnover in active devices: http://www.thisismobility.com/blog/?p=141 I haven't done the exploding of every device's capabilities into every cache file, but I think that might be a good one. Thanks for the reply! - Mike Hey Andrea,
Actually, I had read the stuff about caching at wurfl.sourceforge.net, but I found a lot of them weren’t true for the environment I was working in. I think it’s because I’m working with a much bigger active device list than most sites do. The churn in the agent2id cache was actually generating a lot more load than it was saving. I made a few other changes I think might be interesting for folks running sites with frequent turnover in active devices:

http://www.thisismobility.com/blog/?p=141

I haven’t done the exploding of every device’s capabilities into every cache file, but I think that might be a good one. Thanks for the reply!
- Mike

]]> By: Andrea Trasatti http://www.thisismobility.com/blog/2006/06/10/increasing-the-performance-of-wurfl-for-at-least-one-case/#comment-9423 Andrea Trasatti Thu, 22 Jun 2006 10:30:13 +0000 http://www.thisismobility.com/blog/?p=131#comment-9423 Hi Mike, thanks for the good post on WURFL. It's always good to see people's experiments. It's just a pity that you took this time hacking the PHP library when you could have found the exact same conclusions on the WURFL website. Take a look at this page and paragraph: http://wurfl.sourceforge.net/php/index.php#caching There is also another performance improvement that you might consider, that is to reduce the number of files in the directory. You could: a) generate symbolic links when a device in WURFL doesn't have any specific capability instead of a real file. This breaks a little bit the fall_back tree, but if performance is your concern, this should help b) store the tiny cache files in a directory tree instead of a single directory. Using the first 3-4 characters should be enough. A final optimization that I considered but never implemented was to explode every device's capabilities in every single cache file. This will mean that when a user-agent hits your site you will find all the device information in a single cache file and not load 3, 4 or 5 tiny files. Of course APC helps you in your current configuration as it has all the most common files in shared memory which is even faster the loading a file. You could do this in the update_cache.php script, because I can tell you it will take time. Some performance tests showed that depending on the file size, sometimes var_dump is better performing, some other times serialize is better. I'll leave to you these tests, if you'd like. wurfl_parser.php already has the lines, you just need to adapt them to the multicache. - Andrea Hi Mike,
thanks for the good post on WURFL. It’s always good to see people’s experiments. It’s just a pity that you took this time hacking the PHP library when you could have found the exact same conclusions on the WURFL website. Take a look at this page and paragraph:
http://wurfl.sourceforge.net/php/index.php#caching

There is also another performance improvement that you might consider, that is to reduce the number of files in the directory. You could:
a) generate symbolic links when a device in WURFL doesn’t have any specific capability instead of a real file. This breaks a little bit the fall_back tree, but if performance is your concern, this should help
b) store the tiny cache files in a directory tree instead of a single directory. Using the first 3-4 characters should be enough.

A final optimization that I considered but never implemented was to explode every device’s capabilities in every single cache file. This will mean that when a user-agent hits your site you will find all the device information in a single cache file and not load 3, 4 or 5 tiny files. Of course APC helps you in your current configuration as it has all the most common files in shared memory which is even faster the loading a file. You could do this in the update_cache.php script, because I can tell you it will take time.

Some performance tests showed that depending on the file size, sometimes var_dump is better performing, some other times serialize is better. I’ll leave to you these tests, if you’d like. wurfl_parser.php already has the lines, you just need to adapt them to the multicache.

- Andrea

]]> By: Mike Rowehl: This is Mobility » Blog Archive » WURFL Lightweight for PHP http://www.thisismobility.com/blog/2006/06/10/increasing-the-performance-of-wurfl-for-at-least-one-case/#comment-9350 Mike Rowehl: This is Mobility » Blog Archive » WURFL Lightweight for PHP Wed, 21 Jun 2006 22:40:42 +0000 http://www.thisismobility.com/blog/?p=131#comment-9350 [...] I had another one of those WURFL hacking episodes aimed at getting WURFL to work better for sites with large groups of active devices. And here it is. I’ve started calling it WURFL lightweight. Everyone looks up device info by user agent, so it’s optimized for that. It also assumes a few things: [...] [...] I had another one of those WURFL hacking episodes aimed at getting WURFL to work better for sites with large groups of active devices. And here it is. I’ve started calling it WURFL lightweight. Everyone looks up device info by user agent, so it’s optimized for that. It also assumes a few things: [...]

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