Hi,

The mobile joomla pro adds 'user-agent' to the Vary response header. This is a really, really bad thing to do as it means any downstream caches will have to maintain a separate cache-copy for every single user-agent that accesses the site. Basically it means any site behind a CDN might as well not have the CDN there.

Similarly, anyone running Varnish is going to have similar issues.

I think I can see why you've added it - to ensure that a mobile device never gets served a desktop page (and vice-versa). My aim is to remove this header from the plugin, but I need to understand exactly what the logic for adding it was so that I can create an appropriate alternative (i.e. minimise the impact).

Could you explain what you were hoping to achieve? Obviously any changes/improvements will get contributed back.

Thanks

It's because of detecting of mobile mode (desktop, smartphone, iphone, or tablet) is based on User-Agent header. I don't know other way to prevent incorrect serving by proxies.

In the case of Varnish it would be possible to write vcl_recv subroutine to detect device type, but it is specific case, so I think that Vary: User-Agent should be enabled by default. And anyway, it is not easy to transform mobile detetcting plugins to Varnish subroutine (if possible).