404's from one user agent and a suggestion

Morning Grzegorz;
Regarding WPFC’s cache; there’s code in AO to purge WPFC’s cache as well, but maybe Emre (the dev) changed something on his side. I’ll test later today and fix if possible.

Regarding 404’s from mobile browsers with a google site as referrer; the browser is Chrome on Android, which indeed has “Mobile Safari” in the user agent string. Either those indeed have a bug, making them cache the pages for too long a time or they use the (old) HTML from Google’s cache (maybe with accelerated browsing in Chrome). Have you seen this yourself on a mobile phone?

Afraid I don’t see an easy workaround for that. Maybe manually create a “fallback.js” and “fallback.css” and redirect (using .htaccess) to those in the requested files are not found?

frank

hmmm … do you have “mobile” and “browser caching” active in WPFC?

The behavior is the same regardless of that option in WPFC – I’ve tried it on and off.
I am an apple shop as well as most my colleagues from my work. Well, we get that apple stuff from the employer, so almost nobody has android phones nor tablets. I found two devices but everything was OK with them and they haven’t generated any 404’s. I had no way to test it more, but I admin I haven’t gone the extra mile as for sure I know more people with androids.

I dug into that now and according to wiki: https://en.wikipedia.org/wiki/Chromium_%28web_browser%29 chromium engine had version 40.0.2214.91 on 21 January 2015 – exactly year ago. I don’t see any newer version in the logs so it seems it might have been one off bug. Strange that people don’t upgrade their apps. The devices I tested might have used the latest version.

I thought about creating a fallback file and redirecting to it in case of 404, but your plugin produces so many js and css files after every cache clean – they differ and I had no idea which one to choose – any advice on that?

Thanks for the fantastic support.

if AO creates that many files, you might want to look into the “cache size” part of the FAQ.

regarding contents of “fallback”-files; go to a random page (the most default one) and copy the JS and CSS from that one?

oh, are you hosted on windows or linux?

frank

I am hosted on Linux of course. OK, I think I will manage. Thanks a lot!

I am hosted on Linux of course.

??

(looking into the WPFC cache purging failing, Emre uses rename() which has known quirks on windows, but if you’re on linux then that’s not the problem)

could you check if you have any WPFC-related errors in your PHP-errorlog?

I for example have;

[04-Feb-2016 09:13:14 UTC] PHP Warning: rename(E:\xampp\htdocs\wordpress\wp-content\plugins/cache/all,E:\xampp\htdocs\wordpress\wp-content\plugins/cache/tmpWpfc/1454577194): Access is denied. (code: 5) in E:\xampp\htdocs\wordpress\wp-content\plugins\wp-fastest-cache\wpFastestCache.php on line 580

on a windows machine. I wonder if there’s similar stuff in your errorlog ..

No, I am checking my php error log and I haven’t seen anything like that. Regarding my suggestion – when you display the string that the cache has been cleaned maybe you could add also that the caching plugin has been cleaned as well?

Frank, I am changing it to not resolved as I checked: https://en.wikipedia.org/wiki/Google_Chrome_release_history
It seems all Chrome builds in last 2-3 years use the layout engine 537.36. So the bug affects not one Chrome version, but all recent versions. Do you know what we could do to fix it?

I can live with unresolved topics B-)

Nothing more AO can do really, as this isn’t a problem of AO but of certain useragents (Chrome on Android) in certain cases requesting a page (not by normal browsing, but from _a_ cache, maybe google’s) which has references to AO-files which you deleted already ??

so you could always not empty AO’s cache? and the “fallback JS/CSS” solution would also be a nice workaround.

have a nice weekend,
frank

Yes, but the problem is I don’t delete any files. It seems it is WP fastest cache that deletes all your cache files by the way :/
I think I will report it as a bug to Emre.